United States Natural Gas Fund, LP - Annual Report: 2012 (Form 10-K)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

or

Commission file number: 001-33096

United States Natural Gas Fund, LP

(Exact name of registrant as specified in its charter)

1999 Harrison Street, Suite 1530

Oakland, California 94612

(Address of principal executive offices) (Zip code)

(510) 522-9600

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.     ¨  Yes    x  No

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    ¨  Yes    x  No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    x  Yes    ¨  No

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    x  Yes    ¨  No

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    ¨  Yes    x  No

The aggregate market value of the registrant’s units held by non-affiliates of the registrant as of June 30, 2012 was: $1,162,540,322.

The registrant had 56,266,476 outstanding units as of February 22, 2013.

DOCUMENTS INCORPORATED BY REFERENCE:

None.

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UNITED STATES NATURAL GAS FUND, LP

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Part I

Item 1. Business.

What is USNG?

The United States Natural Gas Fund, LP (“USNG”) is a Delaware limited partnership organized on September 11, 2006. USNG maintains its main business office at 1999 Harrison Street, Suite 1530, Oakland, California 94612. USNG is a commodity pool that issues limited partnership interests (“units”) traded on the NYSE Arca, Inc. (the “NYSE Arca”). It operates pursuant to the terms of the Third Amended and Restated Agreement of Limited Partnership dated as of December 31, 2010 (as amended from time to time, the “LP Agreement”), which grants full management control to its general partner, United States Commodity Funds LLC (“USCF”).

The investment objective of USNG is for the daily changes in percentage terms of its units’ per unit net asset value (“NAV”) to reflect the daily changes in percentage terms of the spot price of natural gas delivered at the Henry Hub, Louisiana, as measured by the daily changes in the price of the futures contract for natural gas traded on the New York Mercantile Exchange (the “NYMEX”), that is the near month contract to expire, except when the near month contract is within two weeks of expiration, in which case it will be measured by the futures contract that is the next month contract to expire, less USNG’s expenses. It is not the intent of USNG to be operated in a fashion such that the per unit NAV will equal, in dollar terms, the spot price of natural gas or any particular futures contract based on natural gas. It is not the intent of USNG to be operated in a fashion such that its per unit NAV will reflect the percentage change of the price of any particular futures contract as measured over a time period greater than one day. USCF believes that it is not practical to manage the portfolio to achieve such an investment goal when investing in Futures Contracts (as defined below) and Other Natural Gas-Related Investments (as defined below). USNG’s units began trading on April 18, 2007. USCF is the general partner of USNG and is responsible for the management of USNG.

Who is USCF?

USCF is a single member limited liability company that was formed in the state of Delaware on May 10, 2005. Prior to June 13, 2008, USCF was known as Victoria Bay Asset Management, LLC. It maintains its main business office at 1999 Harrison Street, Suite 1530, Oakland, California 94612. USCF is a wholly owned subsidiary of Wainwright Holdings, Inc., a Delaware corporation (“Wainwright”). Mr. Nicholas Gerber (discussed below) controls Wainwright by virtue of his ownership of Wainwright’s shares. Wainwright is a holding company that previously owned an insurance company organized under Bermuda law (which has been liquidated) and a registered investment adviser firm named Ameristock Corporation, which has been distributed to the Wainwright shareholders. USCF is a member of the National Futures Association (the “NFA”) and registered as a commodity pool operator (“CPO”) with the Commodity Futures Trading Commission (the “CFTC”) on December 1, 2005.

USCF also serves as general partner or sponsor of the United States Oil Fund, LP (“USOF”), the United States 12 Month Oil Fund, LP (“US12OF”), the United States Gasoline Fund, LP (“UGA”), the United States Diesel-Heating Oil Fund, LP (formerly, the United States Heating Oil Fund, LP) (“USDHO”), the United States Short Oil Fund, LP (“USSO”), the United States 12 Month Natural Gas Fund, LP (“US12NG”), the United States Brent Oil Fund, LP (“USBO”), the United States Commodity Index Fund (“USCI”), the United States Copper Index Fund (“CPER”), the United States Agriculture Index Fund (“USAG”) and the United States Metals Index Fund (“USMI”). USOF, US12OF, UGA, USDHO, USSO, US12NG, USBO, USCI, CPER, USAG and USMI are actively operating funds and all are listed on the NYSE Arca. All funds listed previously are referred to collectively herein as the “Related Public Funds.” The Related Public Funds are subject to reporting requirements under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). For more information about each of the Related Public Funds, investors in USNG may call 1.800.920.0259 or visit www.unitedstatescommodityfunds.com or the SEC’s website at www.sec.gov.

USCF has also filed registration statements to register units of the United States Sugar Fund (“USSF”), the United States Natural Gas Double Inverse Fund (“UNGD”), the United States Gasoil Fund (“USGO”) and the United States Asian Commodities Basket Fund (“UAC”), each of which is a series of the United States Commodity Funds Trust I, and the US Golden Currency Fund (“HARD”), a series of the United States Currency Funds Trust. USSF, UNGD, USGO and HARD are currently not available to the public, as such funds are still in the process of review by various regulatory agencies which have regulatory authority over USCF and such funds. UAC has been declared effective by the regulatory agencies which have regulatory authority over USCF and UAC, but at the time of filing of this annual report on Form 10-K, UAC has not been made available to the public.

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USCF is required to evaluate the credit risk of USNG to the futures commission merchant (“FCM”), oversee the purchase and sale of USNG’s units by certain authorized purchasers (“Authorized Purchasers”), review daily positions and margin requirements of USNG and manage USNG’s investments. USCF also pays the fees of ALPS Distributors, Inc., which serves as the marketing agent for USNG (the “Marketing Agent”), and Brown Brothers Harriman & Co. (“BBH&Co.”), which serves as the administrator (the “Administrator”) and the custodian (the “Custodian”) for USNG.

Limited partners have no right to elect USCF as the general partner on an annual or any other continuing basis. If USCF voluntarily withdraws as general partner, however, the holders of a majority of USNG’s outstanding units (excluding for purposes of such determination units owned, if any, by the withdrawing USCF and its affiliates) may elect its successor. USCF may not be removed as general partner except upon approval by the affirmative vote of the holders of at least 66 and ²/3 percent of USNG’s outstanding units (excluding units owned, if any, by USCF and its affiliates), subject to the satisfaction of certain conditions set forth in the LP Agreement.

The business and affairs of USCF are managed by a board of directors (the “Board”), which is comprised of three management directors (the “Management Directors”), some of whom are also its executive officers, and three independent directors who meet the independent director requirements established by the NYSE Arca Equities Rules and the Sarbanes-Oxley Act of 2002. The Management Directors have the authority to manage USCF pursuant to its LLC Agreement, as amended from time to time. Through its Management Directors, USCF manages the day-to-day operations of USNG. The Board has an audit committee which is made up of the three independent directors (Peter M. Robinson, Gordon L. Ellis and Malcolm R. Fobes III). For additional information relating to the audit committee, please see “Item 10. Directors, Executive Officers and Corporate Governance – Audit Committee” in this annual report on Form 10-K.

How Does USNG Operate?

An investment in the units provides a means for diversifying an investor’s portfolio or hedging exposure to changes in natural gas prices. An investment in the units allows both retail and institutional investors to easily gain this exposure to the natural gas market in a transparent, cost-effective manner.

The net assets of USNG consist primarily of investments in futures contracts for natural gas, crude oil, diesel-heating oil, gasoline, and other petroleum-based fuels that are traded on the NYMEX, ICE Futures or other U.S. and foreign exchanges (collectively, “Futures Contracts”) and, to a lesser extent, in order to comply with regulatory requirements or in view of market conditions, other natural gas-related investments such as cash-settled options on Futures Contracts, forward contracts for natural gas, cleared swap contracts and non-exchange traded (“over-the-counter”) transactions that are based on the price of natural gas, oil and other petroleum-based fuels, Futures Contracts and indices based on the foregoing (collectively, “Other Natural Gas-Related Investments”). Market conditions that USCF currently anticipates could cause USNG to invest in Other Natural Gas-Related Investments include those allowing USNG to obtain greater liquidity or to execute transactions with more favorable pricing. For convenience and unless otherwise specified, Futures Contracts and Other Natural Gas-Related Investments collectively are referred to as “Natural Gas Interests” in this annual report on Form 10-K. USNG invests substantially the entire amount of its assets in Futures Contracts while supporting such investments by holding the amounts of its margin, collateral and other requirements relating to these obligations in short-term obligations of the United States of two years or less (“Treasuries”), cash and cash equivalents. The daily holdings of USNG are available on USNG’s website at www.unitedstatesnaturalgasfund.com.

The investment objective of USNG is for the daily changes in percentage terms of its units’ per unit NAV to reflect the daily changes in percentage terms of the spot price of natural gas delivered at the Henry Hub, Louisiana as measured by the daily changes in the price of the Futures Contract on natural gas traded on the NYMEX that is the near month contract to expire, except when the near month contract is within two weeks of expiration, in which case it will be measured by the futures contract that is the next month contract to expire (the “Benchmark Futures Contract”), less USNG’s expenses. It is not the intent of USNG to be operated in a fashion such that its per unit NAV will equal, in dollar terms, the spot price of natural gas or any particular futures contract based on natural gas. It is not the intent of USNG to be operated in a fashion such that its per unit NAV will reflect the percentage change of the price of any particular futures contract as measured over a time period greater than one day. USNG may invest in interests other than the Benchmark Futures Contract to comply with accountability levels and position limits. For a detailed discussion of accountability levels and position limits, see “Item 1. Business – What are Futures Contracts?” below in this annual report on Form 10-K.

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USCF employs a “neutral” investment strategy in order to track changes in the price of the Benchmark Futures Contract regardless of whether the price goes up or goes down. USNG’s “neutral” investment strategy is designed to permit investors generally to purchase and sell USNG’s units for the purpose of investing indirectly in natural gas in a cost-effective manner, and/or to permit participants in the natural gas or other industries to hedge the risk of losses in their natural gas-related transactions. Accordingly, depending on the investment objective of an individual investor, the risks generally associated with investing in natural gas and/or the risks involved in hedging may exist. In addition, an investment in USNG involves the risk that the changes in the price of USNG’s units will not accurately track the changes in the Benchmark Futures Contract, and that changes in the Benchmark Futures Contract will not closely correlate with changes in the spot prices of natural gas.

The Benchmark Futures Contract is changed from the near month contract to the next month contract over a four-day period. Each month, the Benchmark Futures Contract changes starting at the end of the day on the date two weeks prior to expiration of the near month contract for that month. During the first three days of the period, the applicable value of the Benchmark Futures Contract is based on a combination of the near month contract and the next month contract as follows: (1) day 1 consists of 75% of the then near month contract’s price plus 25% of the price of the next month contract, divided by 75% of the near month contract’s prior day’s price plus 25% of the price of the next month contract, (2) day 2 consists of 50% of the then near month contract’s price plus 50% of the price of the next month contract, divided by 50% of the near month contract’s prior day’s price plus 50% of the price of the next month contract, and (3) day 3 consists of 25% of the then near month contract’s price plus 75% of the price of the next month contract, divided by 25% of the near month contract’s prior day’s price plus 75% of the price of the next month contract. On day 4, the Benchmark Futures Contract is the next month contract to expire at that time and that contract remains the Benchmark Futures Contract until the beginning of the following month’s change in the Benchmark Futures Contract over a four-day period.

On each day during the four-day period, USCF anticipates it will “roll” USNG’s positions in Natural Gas Interests by closing, or selling, a percentage of USNG’s positions in Natural Gas Interests and reinvesting the proceeds from closing those positions in new Natural Gas Interests that reflect the change in the Benchmark Futures Contract.

The anticipated dates that the monthly four-day roll period will commence are posted on USNG’s website at www.unitedstatesnaturalgasfund.com, and are subject to change without notice.

USNG’s total portfolio composition is disclosed on its website each business day that the NYSE Arca is open for trading. The website disclosure of portfolio holdings is made daily and includes, as applicable, the name and value of each Natural Gas Interest, the specific types of Other Natural Gas-Related Investments and characteristics of such Other Natural Gas-Related Investments, the name and value of each Treasury and cash equivalent, and the amount of cash held in USNG’s portfolio. USNG’s website is publicly accessible at no charge. USNG’s assets used for margin and collateral are held in segregated accounts pursuant to the Commodity Exchange Act (the “CEA”) and CFTC regulations.

The units issued by USNG may only be purchased by Authorized Purchasers and only in blocks of 100,000 units called Creation Baskets. The amount of the purchase payment for a Creation Basket is equal to the aggregate NAV of the units in the Creation Basket. Similarly, only Authorized Purchasers may redeem units and only in blocks of 100,000 units called Redemption Baskets. The amount of the redemption proceeds for a Redemption Basket is equal to the aggregate NAV of units in the Redemption Basket. The purchase price for Creation Baskets, and the redemption price for Redemption Baskets are the actual NAV calculated at the end of the business day when a request for a purchase or redemption is received by USNG. The NYSE Arca publishes an approximate per unit NAV intra-day based on the prior day’s per unit NAV and the current price of the Benchmark Futures Contract, but the price of Creation Baskets and Redemption Baskets is determined based on the actual per unit NAV calculated at the end of the day.

While USNG issues units only in Creation Baskets, units are listed on the NYSE Arca and investors may purchase and sell units at market prices like any listed security.

What is USNG’s Investment Strategy?

In managing USNG’s assets, USCF does not use a technical trading system that issues buy and sell orders. USCF instead employs a quantitative methodology whereby each time a Creation Basket is sold, USCF purchases Natural Gas Interests, such as the Benchmark Futures Contract, that have an aggregate market value that approximates the amount of Treasuries and/or cash received upon the issuance of the Creation Basket.

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By remaining invested as fully as possible in Futures Contracts or Other Natural Gas-Related Investments, USCF believes that the daily changes in percentage terms in USNG’s per unit NAV will continue to closely track the daily changes in percentage terms in the price of the Benchmark Futures Contract. USCF believes that certain arbitrage opportunities result in the price of the units traded on the NYSE Arca closely tracking the per unit NAV of USNG. Additionally, Futures Contracts traded on the NYMEX have closely tracked the spot price of natural gas. Based on these expected interrelationships, USCF believes that the changes in the price of USNG’s units traded on the NYSE Arca have closely tracked and will continue to closely track the changes in the spot price of natural gas. For performance data relating to USNG’s ability to track its benchmark, see “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations — Tracking USNG’s Benchmark” in this annual report on Form 10-K.

USCF endeavors to place USNG’s trades in Futures Contracts and Other Natural Gas-Related Investments and otherwise manage USNG’s investments so that “A” will be within plus/minus 10 percent of “B,” where:

USCF believes that market arbitrage opportunities will cause the daily changes in USNG’s unit price on the NYSE Arca to closely track the daily changes in USNG’s per unit NAV. USCF believes that the net effect of these two expected relationships and the relationships described above between USNG’s per unit NAV and the Benchmark Futures Contract will be that the daily changes in the price of USNG’s units on the NYSE Arca will closely track, in percentage terms, the changes in the spot price of a barrel of natural gas, less USNG’s expenses. For performance data relating to USNG’s ability to track its benchmark, see “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations – Tracking USNG’s Benchmark” in this annual report on Form 10-K.

The specific Futures Contracts purchased depend on various factors, including a judgment by USCF as to the appropriate diversification of USNG’s investments in futures contracts with respect to the month of expiration, and the prevailing price volatility of particular contracts. While USCF has made significant investments in NYMEX Futures Contracts, for various reasons, including the ability to enter into the precise amount of exposure to the natural gas market, position limits or other regulatory requirements limiting USNG’s holdings, and market conditions, it may invest in Futures Contracts traded on other exchanges or invest in Other Natural Gas-Related Investments. To the extent that USNG invests in Other Natural Gas-Related Investments, it would prioritize investments in contracts and instruments that are economically equivalent to the Benchmark Futures Contract, including cleared swaps that satisfy such criteria, and then, to a lesser extent, it would invest in other types of cleared swaps and other contracts, instruments and non-cleared swaps, such as swaps in the over-the-counter market. If USNG is required by law or regulation, or by one of its regulators, including a futures exchange, to reduce its position in the Futures Contract to the applicable position limit or to a specified accountability level or if market conditions dictate it would be more appropriate to invest in Other Natural Gas-Related Investments, a substantial portion of USNG’s assets could be invested in accordance with such priority in Other Natural Gas-Related Investments that are intended to replicate the return on the Benchmark Futures Contract. As USNG’s assets reach higher levels, it is more likely to exceed position limits, accountability levels or other regulatory limits and, as a result, it is more likely that it will invest in accordance with such priority in Other Natural Gas-Related Investments at such higher levels. In addition, market conditions that USCF currently anticipates could cause USNG to invest in Other Natural Gas-Related Investments include those allowing USNG to obtain greater liquidity or to execute transactions with more favorable pricing. See “Item 1. Business – Regulation” in this annual report on Form 10-K for a discussion of the potential impact of the Dodd-Frank Wall Street Reform and Consumer Protection Act (the “Dodd-Frank Act”) on USNG’s ability to invest in over-the-counter transactions and cleared swaps.

USCF may not be able to fully invest USNG’s assets in the Futures Contract having an aggregate notional amount exactly equal to USNG’s NAV. For example, as standardized contracts, the Futures Contracts are for a specified amount of a particular commodity, and USNG’s NAV and the proceeds from the sale of a Creation Basket are unlikely to be an exact multiple of the amounts of those contracts. As a result, in such circumstances, USNG may be better able to achieve the exact amount of exposure to changes in price of the Benchmark Futures Contract through the use of Other Natural Gas-Related Investments, such as over-the-counter contracts that have better correlation with changes in price of the Benchmark Futures Contract.

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USNG anticipates that to the extent it invests in Futures Contracts other than contracts on natural gas (such as futures contracts for light, sweet crude oil, diesel-heating oil and other petroleum-based fuels) and Other Natural Gas-Related Investments, it will enter into various non-exchange-traded derivative contracts to hedge the short-term price movements of such Futures Contracts and Other Natural Gas-Related Investments against the current Benchmark Futures Contract.

USCF does not anticipate letting USNG’s Futures Contracts expire and taking delivery of the underlying commodity. Instead, USCF closes existing positions, e.g., when it changes the Benchmark Futures Contract or Other Natural Gas-Related Investments or it otherwise determines it would be appropriate to do so and reinvests the proceeds in new Futures Contracts or Other Natural Gas-Related Investments. Positions may also be closed out to meet orders for Redemption Baskets and in such case proceeds for such baskets will not be reinvested.

What is the Natural Gas Market and the Petroleum-Based Fuel Market?

Natural Gas. Natural gas accounts for almost a quarter of U.S. energy consumption. The price of natural gas is established by the supply and demand conditions in the North American market, and more particularly, in the main refining center of the U.S. Gulf Coast. The natural gas market essentially constitutes an auction, where the highest bidder wins the supply. When markets are “strong” (i.e., when demand is high and/or supply is low), the bidder must be willing to pay a higher premium to capture the supply. When markets are “weak” (i.e., when demand is low and/or supply is high), a bidder may choose not to outbid competitors, waiting instead for later, possibly lower priced, supplies. Demand for natural gas by consumers, as well as agricultural, manufacturing and transportation industries, determines overall demand for natural gas. Since the precursors of product demand are linked to economic activity, natural gas demand will tend to reflect economic conditions. However, other factors such as weather significantly influence natural gas demand.

The NYMEX is the world’s largest physical commodity futures exchange and the dominant market for the trading of energy and precious metals. The Benchmark Futures Contract trades in units of 10,000 MMBtu and is based on delivery at the Henry Hub in Louisiana, the nexus of 16 intra- and interstate natural gas pipeline systems that draw supplies from the region’s prolific gas deposits. The pipelines serve markets throughout the U.S. East Coast, the Gulf Coast, the Midwest, and up to the Canadian border. Because of the volatility of natural gas prices, a vigorous basis market has developed in the pricing relationships between the Henry Hub and other important natural gas market centers in the continental United States and Canada. The NYMEX makes available for trading a series of basis swap futures contracts that are quoted as price differentials between approximately 30 natural gas pricing points and the Henry Hub. The basis contracts trade in units of 2,500 MMBtu on the New York Mercantile Exchange ClearPort^® trading platform. The New York Mercantile Exchange ClearPort^® is an electronic trading platform through which a slate of energy futures contracts are available for competitive trading. Transactions can also be consummated off-NYMEX and submitted to the NYMEX for clearing via the NYMEX ClearPort^® clearing website as an exchange of futures for physicals or an exchange of futures for swaps transactions.

Light, Sweet Crude Oil. Crude oil is the world’s most actively traded commodity. The futures contracts for light, sweet crude oil that are traded on the NYMEX are the world’s most liquid forum for crude oil trading, as well as the world’s largest volume futures contract trading on a physical commodity. Due to the liquidity and price transparency of oil futures contracts, they are used as a principal international pricing benchmark. The futures contracts for light, sweet crude oil trade on the NYMEX in units of 1,000 U.S. barrels (42,000 gallons) and, if not closed out before maturity, will result in delivery of oil to Cushing, Oklahoma, which is also accessible to the international spot markets via pipelines.

Demand for petroleum products by consumers, as well as agricultural, manufacturing and transportation industries, determines demand for crude oil by refiners. Since the precursors of product demand are linked to economic activity, crude oil demand will tend to reflect economic conditions. However, other factors such as weather also influence product and crude oil demand.

Crude oil supply is determined by both economic and political factors. Oil prices (along with drilling costs, availability of attractive prospects for drilling, taxes and technology, among other factors) determine exploration and development spending, which influence output capacity with a lag. In the short run, production decisions by the Organization of Petroleum Exporting Countries (“OPEC”) also affect supply and prices. Oil export embargoes and the current conflict in Iraq represent other routes through which political developments move the market. It is not possible to predict the aggregate effect of all or any combination of these factors.

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Diesel-Heating Oil. Diesel-heating oil, also known as No. 2 fuel oil, accounts for 25% of the yield of a barrel of crude oil, the second largest “cut” from oil after gasoline. The diesel-heating oil futures contract listed and traded on the NYMEX trades in units of 42,000 gallons (1,000 barrels) and is based on delivery in the New York harbor, the principal cash market center. The ICE Futures also offers a Diesel-Heating Oil Futures Contract which trades in units of 42,000 U.S. gallons (1,000 barrels). The Diesel-Heating Oil Futures Contract is cash-settled against the prevailing market price for diesel-heating oil delivered to the New York Harbor.

Gasoline. Gasoline is the largest single volume refined product sold in the U.S. and accounts for almost half of national oil consumption. The gasoline futures contract listed and traded on the NYMEX trades in units of 42,000 gallons (1,000 barrels) and is based on delivery at petroleum products terminals in the New York harbor, the major East Coast trading center for imports and domestic shipments from refineries in the New York harbor area or from the Gulf Coast refining centers. The price of gasoline has historically been volatile.

What are Futures Contracts?

Futures Contracts are agreements between two parties. One party agrees to buy a commodity such as natural gas from the other party at a later date at a price and quantity agreed upon when the contract is made. Futures Contracts are traded on futures exchanges, including the NYMEX. For example, the Benchmark Futures Contract is traded on the NYMEX in units of 10,000 MMBtu. Futures Contracts traded on the NYMEX are priced by floor brokers and other exchange members both through an “open outcry” of offers to purchase or sell the contracts and through an electronic, screen-based system that determines the price by matching electronically offers to purchase and sell. Additional risks of investing in Futures Contracts are included in “Item 1A. Risk Factors” in this annual report on Form 10-K.

Impact of Accountability Levels, Position Limits and Price Fluctuation Limits. Futures contracts include typical and significant characteristics. Most significantly, the CFTC and U.S. designated contract markets such as the NYMEX have established accountability levels and position limits on the maximum net long or net short futures contracts in commodity interests that any person or group of persons under common trading control (other than as a hedge, which an investment by USNG is not) may hold, own or control. The net position is the difference between an individual or firm’s open long contracts and open short contracts in any one commodity. In addition, most U.S.-based futures exchanges, such as the NYMEX, limit the daily price fluctuation for futures contracts. Currently, the ICE Futures imposes position and accountability limits that are similar to those imposed by U.S.-based futures exchanges and also limits the maximum daily price fluctuation, while some other non-U.S. futures exchanges have not adopted such limits.

The accountability levels for the Benchmark Futures Contract and other Futures Contracts traded on U.S.-based futures exchanges, such as the NYMEX, are not a fixed ceiling, but rather a threshold above which the NYMEX may exercise greater scrutiny and control over an investor’s positions. The current accountability level for investments for any one-month in the Benchmark Futures Contract is 6,000 net contracts. In addition, the NYMEX imposes an accountability level for all months of 12,000 net futures contracts for natural gas. In addition, the ICE Futures maintains the same accountability levels, position limits and monitoring authority for its natural gas contract as the NYMEX. If USNG and the Related Public Funds exceed these accountability levels for investments in the futures contract for natural gas, the NYMEX and ICE Futures will monitor such exposure and may ask for further information on their activities, including the total size of all positions, investment and trading strategy, and the extent of liquidity resources of USNG and the Related Public Funds. If deemed necessary by the NYMEX and/or ICE Futures, USNG could be ordered to reduce its aggregate position back to the accountability level. As of December 31, 2012, USNG held 17,891 NYMEX Natural Gas Futures NG contracts and 17,952 NYMEX Natural Gas Futures NN contracts. As of December 31, 2012, USNG held 30,192 natural gas cleared-swap contracts traded on the ICE Futures. USNG exceeded accountability levels of the NYMEX during the year ended December 31, 2012, when it held a maximum of 25,065 Natural Gas Futures NG contracts and 19,952 Natural Gas Financial Futures NN contracts, exceeding both the “any” and “all” month limits. No action was taken by the NYMEX and USNG did not reduce the number of Futures Contracts held as a result. USNG exceeded accountability levels of ICE Futures during the year ended December 31, 2012, when it held a maximum of 44,808 natural gas cleared swap contracts, exceeding the “any” month limit. No action was taken by ICE Futures and USNG did not reduce the number of cleared swap contracts held as a result.

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Position limits differ from accountability levels in that they represent fixed limits on the maximum number of futures contracts that any person may hold and cannot allow such limits to be exceeded without express CFTC authority to do so. In addition to accountability levels and position limits that may apply at any time, the NYMEX and ICE Futures impose position limits on contracts held in the last few days of trading in the near month contract to expire. It is unlikely that USNG will run up against such position limits because USNG’s investment strategy is to close out its positions and “roll” from the near month contract to expire to the next month contract during a four-day period beginning two weeks from expiration of the contract. For the year ended December 31, 2012, USNG did not exceed any position limits imposed by the NYMEX and ICE Futures.

In late 2011, the CFTC adopted rules that impose new position limits on Referenced Contracts (as defined below) involving 28 energy, metals and agricultural commodities (the “Position Limit Rules”). The Position Limit Rules were scheduled to become effective on October 12, 2012. However, on September 28, 2012, the United States District Court for the District of Columbia vacated these regulations on the basis of ambiguities in the provisions of the CEA (as modified by the Dodd-Frank Act) upon which the regulations were based. In its September 28, 2012 decision, the court remanded the Position Limit Rules to the CFTC with instructions to use its expertise and experience to resolve the ambiguities in the statute. On November 15, 2012, the CFTC indicated that it will move forward with an appeal of the District Court’s decision to vacate the Position Limit Rules. At this time, it is not possible to predict how the CFTC’s appeal could affect USNG, but it may be substantial and adverse. Furthermore, until such time as the appeal is resolved or, if applicable revisions to the Position Limit Rules are proposed and adopted, the regulatory architecture in effect prior to the enactment of the Position Limit Rules will govern transactions in commodities and related derivatives (collectively, “Referenced Contracts). Under that system, the CFTC enforces federal limits on speculation in agricultural products (e.g., corn, wheat and soy), while futures exchanges enforce position limits and accountability levels for agricultural and certain energy products (e.g., oil and natural gas). As a result, USNG may be limited with respect to the size of its investments in any commodities subject to these limits. Finally, subject to certain narrow exceptions, the vacated Position Limit Rules would have required the aggregation, for purposes of the position limits, of all positions in the 28 Referenced Contracts held by a single entity and its affiliates, regardless of whether such position existed on U.S. futures exchanges, non-U.S. futures exchanges, in cleared swaps or in over-the-counter swaps. The CFTC is presently considering new aggregation rules, under a rulemaking proposal that is distinct from the Position Limit Rules. At this time, it is unclear how any modified aggregation rules may affect USNG, but it may be substantial and adverse. By way of example, the aggregation rules in combination with any potential revised Position Limit Rules may negatively impact the ability of USNG to meet its investment objectives through limits that may inhibit USCF’s ability to sell additional Creation Baskets of USNG. See “Commodity Interest Markets – Regulation” in this annual report on Form 10-K for information regarding the Dodd-Frank Act.

Price Volatility. The price volatility of Futures Contracts generally has been historically greater than that for traditional securities such as stocks and bonds. Price volatility often is greater day-to-day as opposed to intra-day. Futures Contracts tend to be more volatile than stocks and bonds because price movements for natural gas are more currently and directly influenced by economic factors for which current data is available and are traded by natural gas futures traders throughout the day. Because USNG invests a significant portion of its assets in Futures Contracts, the assets of USNG, and therefore the prices of USNG units, may be subject to greater volatility than traditional securities.

Marking-to-Market Futures Positions. Futures Contracts are marked to market at the end of each trading day and the margin required with respect to such contracts is adjusted accordingly. This process of marking-to-market is designed to prevent losses from accumulating in any futures account. Therefore, if USNG’s futures positions have declined in value, USNG may be required to post “variation margin” to cover this decline. Alternatively, if USNG’s futures positions have increased in value, this increase will be credited to USNG’s account.

Why Does USNG Purchase and Sell Futures Contracts?

USNG’s investment objective is for the daily changes in percentage terms of its units’ per unit NAV to reflect the daily changes in percentage terms of the Benchmark Futures Contract, less USNG’s expenses. USNG invests primarily in Futures Contracts. USNG seeks to have its aggregate NAV approximate at all times the aggregate market value of the Futures Contracts (or Other Natural Gas-Related Investments) it holds.

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In connection with investing in Futures Contracts and Other Natural Gas-Related Investments, USNG holds Treasuries, cash and/or cash equivalents that serve as segregated assets supporting USNG’s positions in Futures Contracts and Other Natural Gas-Related Investments. For example, the purchase of a Futures Contract with a notional value of $10 million would not require USNG to pay $10 million upon entering into the contract; rather, only a margin deposit, generally of 5% to 30% of the stated value of the Futures Contract, would be required. To secure its Futures Contract obligations, USNG would deposit the required margin with the FCM and would separately hold, through its Custodian, Treasuries, cash and/or cash equivalents in an amount equal to the balance of the current market value of the contract, which at the contract’s inception would be $10 million minus the amount of the margin deposit, or $9.0 million (assuming a 10% margin).

As a result of the foregoing, typically 5% to 30% of USNG’s assets are held as margin in segregated accounts with a FCM. In addition to the Treasuries and cash it posts with the FCM for the Futures Contracts it owns, USNG may hold, through the Custodian, Treasuries, cash and/or cash equivalents that can be posted as additional margin or as other collateral to support its over-the-counter contracts. USNG earns income from the Treasuries and/or cash equivalents that it purchases, and on the cash it holds through the Custodian or FCM. USNG anticipates that the earned income will increase the NAV and limited partners’ capital contribution accounts. USNG reinvests the earned income, holds it in cash, or uses it to pay its expenses. If USNG reinvests the earned income, it makes investments that are consistent with its investment objective.

What are the Trading Policies of USNG?

Liquidity

USNG invests only in Futures Contracts and Other Natural Gas-Related Investments that, in the opinion of USCF, are traded in sufficient volume to permit the ready taking and liquidation of positions in these financial interests and Other Natural Gas-Related Investments that, in the opinion of USCF, may be readily liquidated with the original counterparty or through a third party assuming the position of USNG.

Spot Commodities

While the Futures Contracts traded on the NYMEX can be physically settled, USNG does not intend to take or make physical delivery. USNG may from time to time trade in Other Natural Gas-Related Investments, including contracts based on the spot price of natural gas.

Leverage

USCF endeavors to have the value of USNG’s Treasuries, cash and cash equivalents, whether held by USNG or posted as margin or other collateral, at all times approximate the aggregate market value of its obligations under its Futures Contracts and Other Natural Gas-Related Investments. Commodity pools’ trading positions in futures contracts or other related investments are typically required to be secured by the deposit of margin funds that represent only a small percentage of a futures contract’s (or other commodity interest’s) entire market value. While USCF has not and does not intend to leverage USNG’s assets, it is not prohibited from doing so under the LP Agreement.

Borrowings

Borrowings are not used by USNG, unless USNG is required to borrow money in the event of physical delivery, if USNG trades in cash commodities, or for short-term needs created by unexpected redemptions.

Over-the-Counter Derivatives (Including Spreads and Straddles)

In addition to Futures Contracts, there are also a number of listed options on the Futures Contracts on the principal futures exchanges. These contracts offer investors and hedgers another set of financial vehicles to use in managing exposure to the natural gas market. Consequently, USNG may purchase options on natural gas Futures Contracts on these exchanges in pursuing its investment objective.

In addition to the Futures Contracts and options on the Futures Contracts, there also exists an active non-exchange-traded market in derivatives tied to natural gas. These derivatives transactions (also known as over-the-counter contracts) are usually entered into between two parties in private contracts. Unlike most of the exchange-traded Futures Contracts or exchange-traded options on the Futures Contracts, each party to such contract bears the credit risk of the other party, i.e., the risk that the other party may not be able to perform its obligations under its contract.

To reduce the credit risk that arises in connection with such contracts, USNG will generally enter into an agreement with each counterparty based on the Master Agreement published by the International Swaps and Derivatives Association, Inc. (“ISDA”) that provides for the netting of its overall exposure to its counterparty.

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USCF assesses or reviews, as appropriate, the creditworthiness of each potential or existing counterparty to an over-the-counter contract pursuant to guidelines approved by USCF’s Board.

USNG may employ spreads or straddles in its trading to mitigate the differences in its investment portfolio and its goal of tracking the price of the Benchmark Futures Contract. USNG would use a spread when it chooses to take simultaneous long and short positions in futures written on the same underlying asset, but with different delivery months.

USNG has employed hedging methods to the extent it invested in fully-collateralized over-the-counter swap transactions designed to track percentage changes in the price of the Benchmark Futures Contract. USNG has been exposed to counterparty risk on these fully-collateralized over-the-counter swap transactions.

Pyramiding

USNG has not and will not employ the technique, commonly known as pyramiding, in which the speculator uses unrealized profits on existing positions as variation margin for the purchase or sale of additional positions in the same or another commodity interest.

Who are the Service Providers?

In its capacity as the Custodian for USNG, BBH&Co. holds USNG’s Treasuries, cash and/or cash equivalents pursuant to a custodial agreement. BBH&Co. is also the registrar and transfer agent for the units. In addition, in its capacity as Administrator for USNG, BBH&Co. performs certain administrative and accounting services for USNG and prepares certain SEC, NFA and CFTC reports on behalf of USNG. USCF pays BBH&Co.’s fees for these services.

BBH&Co.’s principal business address is 50 Milk Street, Boston, MA 02109-3661. BBH&Co., a private bank founded in 1818, is neither a publicly held company nor insured by the Federal Deposit Insurance Corporation. BBH&Co. is authorized to conduct a commercial banking business in accordance with the provisions of Article IV of the New York State Banking Law, New York Banking Law §§160–181, and is subject to regulation, supervision, and examination by the New York State Department of Financial Services. BBH&Co. is also licensed to conduct a commercial banking business by the Commonwealths of Massachusetts and Pennsylvania and is subject to supervision and examination by the banking supervisors of those states.

USNG also employs ALPS Distributors, Inc. as the Marketing Agent. USCF pays the Marketing Agent an annual fee. In no event may the aggregate compensation paid to the Marketing Agent and any affiliate of USCF for distribution-related services in connection with the offering of units exceed ten percent (10%) of the gross proceeds of the offering.

ALPS’s principal business address is 1290 Broadway, Suite 1100, Denver, CO 80203. ALPS is the marketing agent for USNG. ALPS is a broker-dealer registered with the Financial Industry Regulatory Authority (“FINRA”) and a member of the Securities Investor Protection Corporation.

UBS Securities LLC (“UBS Securities”) is USNG’s FCM. USNG and UBS Securities have entered into an Institutional Futures Client Account Agreement. This agreement requires UBS Securities to provide services to USNG in connection with the purchase and sale of Natural Gas Interests that may be purchased or sold by or through UBS Securities for USNG’s account. USNG pays UBS Securities’ commissions for executing and clearing trades on behalf of USNG.

UBS Securities’ principal business address is 677 Washington Blvd, Stamford, CT 06901. UBS Securities is a futures clearing broker for USNG. UBS Securities is registered in the U.S. with FINRA as a broker-dealer and with the CFTC as a FCM. UBS Securities is a member of various U.S. futures and securities exchanges.

UBS is and has been a defendant in numerous legal proceedings, including actions brought by regulatory organizations and government agencies, relating to its securities and commodities business that allege various violations of federal and state securities laws. UBS AG, the ultimate parent company to UBS Securities, files annual reports and quarterly reports to the SEC in which it discloses material information about matters involving, but not limited to, UBS Securities, including information about any material litigation or regulatory investigations (https://www.ubs.com/global/en/about_ubs/investor_relations/quarterly_reporting/2011.html). Actions with respect to UBS Securities’ FCM business are publicly available on the website of the National Futures Association (http://www.nfa.futures.org/).

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On June 27, 2007, the Securities Division of the Secretary of the Commonwealth of Massachusetts (“Massachusetts Securities Division”) filed an administrative complaint (the “Complaint”) and notice of adjudicatory proceeding against UBS Securities, captioned In The Matter of UBS Securities, LLC, Docket No. E-2007-0049, which alleged that UBS Securities violated the Massachusetts Uniform Securities Act (the “Act”) and related regulations by providing the advisers for certain hedge funds with gifts and gratuities in the form of below market office rents, personal loans with below market interest rates, event tickets, and other perks, in order to induce those hedge fund advisers to increase or retain their level of prime brokerage fees paid to UBS Securities. On November 22, 2010, UBS Securities entered into a Consent Order and Settlement with the Massachusetts Securities Division, pursuant to which UBS Securities agreed to implementing a disclosure policy and retaining an independent consultant to monitor the policy. UBS Securities also paid a $100,000 fine.

In the summer of 2008, the Massachusetts Securities Division, Texas State Securities Board, and the New York Attorney General (“NYAG”) all brought actions against UBS and UBS Financial Services, Inc. (“UBS Financial”), alleging violations of various state law anti-fraud provisions in connection with the marketing and sale of auction rate securities.

On August 8, 2008, UBS Securities and UBS Financial Services reached agreements with the SEC, the NYAG, the Massachusetts Securities Division and other state regulatory agencies represented by the North American Securities Administrators Association (“NASAA”) to restore liquidity to all remaining client’s holdings of auction rate securities by June 30, 2012. On October 2, 2008, UBS Securities and UBS Financial entered into a final consent agreement with the Massachusetts Securities Division settling all allegations in the Massachusetts Securities Division’s administrative proceeding against UBS Securities and UBS Financial with regards to the auction rate securities matter. On December 11, 2008, UBS Securities and UBS Financial executed an Assurance of Discontinuance in the auction rate securities settlement with the NYAG. On the same day, UBS Securities and UBS Financial finalized settlements with the SEC. UBS Securities and UBS Financial paid penalties of $75 million to NYAG and an additional $75 million to be apportioned among the participating NASAA states. In March 2010, UBS Securities and UBS Financial and NASAA agreed on final settlement terms, pursuant to which, UBS Securities and UBS Financial agreed to provide client liquidity up to an additional $200 million.

On August 14, 2008 the New Hampshire Bureau of Securities Regulation (the “Bureau”) filed an administrative action against UBS Securities relating to a student loan issuer, the New Hampshire Higher Education Loan Corp. (“NHHELCO”). The complaint alleged fraudulent and unethical conduct in violation of New Hampshire state statutes. On April 14, 2010, UBS entered into a Consent Order resolving all of the Bureau’s claims. UBS Securities paid $750,000 to the Bureau for all costs associated with the Bureau’s investigation. UBS Securities entered a separate civil settlement with NHHELCO and provided a total financial benefit of $20M to NHHELCO.

On April 29, 2010, the CFTC issued an order with respect to UBS Securities and levied a fine of $200,000. The Order stated that on February 6, 2009, UBS Securities’ employee broker aided and abetted UBS Securities’ customer’s concealment of material facts from the NYMEX in violation of Section 9(a)(4) of the CEA, 7 U.S.C. § 13(a)(4) (2006). Pursuant to NYMEX Rules, a block trade must be reported to NYMEX “within five minutes of the time of execution” consistent with the requirements of NYMEX Rule 6.21C(A)(6). Although the block trade in question was executed earlier in the day, UBS Securities’ employee broker aided and abetted its customer’s concealment of facts when, in response to the customer’s request to delay reporting the trade until after the close of trading, UBS Securities’ employee did not report the trade until after the close. Because the employee broker undertook his actions within the scope of his employment, pursuant to Section 2(a)(1)(B) of the CEA, 7 U.S.C. § 2(a)(1)(B) (2006), and Commission Regulation 1.2, 17 C.F.R. § 1.2 (2009), UBS Securities is liable for the employee broker’s aiding and abetting of its customer’s violation of Section 9(a)(4) of the CEA. The fine has been paid and the matter is now closed.

UBS Securities will act only as clearing broker for USNG and as such will be paid commissions for executing and clearing trades on behalf of USNG. UBS Securities has not passed upon the adequacy or accuracy of this annual report on Form 10-K. UBS Securities neither will act in any supervisory capacity with respect to USCF nor participate in the management of USCF or USNG.

UBS Securities is not affiliated with USNG or USCF. Therefore, USNG does not believe that USNG has any conflicts of interest with UBS Securities or their trading principals arising from their acting as USNG’s FCM.

Currently, USCF does not employ commodity trading advisors for the trading of USNG contracts. USCF currently does, however, employ a trading advisor for USCI, CPER, USAG and USMI, SummerHaven Investment Management, LLC (“SummerHaven”). If, in the future, USCF does employ commodity trading advisors for USNG, it will choose each advisor based on arm’s-length negotiations and will consider the advisor’s experience, fees and reputation.

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Fees of USNG

Fees and Compensation Arrangements with USCF and Non-Affiliated Service Providers⁽¹⁾

Compensation to USCF

Fees are calculated on a daily basis (accrued at 1/365 of the applicable percentage of total net assets on that day) and paid on a monthly basis. Total net assets are calculated by taking the current market value of USNG’s total assets and subtracting any liabilities.

Fees and Compensation Arrangements between USNG and Non-Affiliated Service Providers⁽³⁾

New York Mercantile Exchange Licensing Fee⁽⁴⁾

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Expenses Paid or Accrued by USNG through December 31, 2012 in dollar terms:

Expenses Paid or Accrued by USNG through December 31, 2012 as a Percentage of Average Daily Net Assets:

Other Fees. USNG also pays the fees and expenses associated with its tax accounting and reporting requirements. These fees were approximately $1,900,000 for the fiscal year ended December 31, 2012. In addition, USNG is responsible for paying its portion of the directors’ and officers’ liability insurance for USNG and the Related Public Funds and the fees and expenses of the independent directors who also serve as audit committee members of USNG and the Related Public Funds organized as limited partnerships and, as of July 8, 2011, those Related Public Funds organized as a series of a Delaware statutory trust. USNG shares the fees and expenses on a pro rata basis with each Related Public Fund, as described above, based on the relative assets of each fund computed on a daily basis. These fees and expenses for the year ended December 31, 2012 were $540,586 for USNG and the Related Public Funds. USNG’s portion of such fees and expenses for the year ended December 31, 2012 was $172,838.

Form of Units

Registered Form. Units are issued in registered form in accordance with the LP Agreement. The Administrator has been appointed registrar and transfer agent for the purpose of transferring units in certificated form. The Administrator keeps a record of all limited partners and holders of the units in certificated form in the registry (the “Register”). USCF recognizes transfers of units in certificated form only if done in accordance with the LP Agreement. The beneficial interests in such units are held in book-entry form through participants and/or accountholders in the Depository Trust Company (“DTC”).

Book Entry. Individual certificates are not issued for the units. Instead, units are represented by one or more global certificates, which are deposited by the Administrator with DTC and registered in the name of Cede & Co., as nominee for DTC. The global certificates evidence all of the units outstanding at any time. Unitholders are limited to: (1) participants in DTC such as banks, brokers, dealers and trust companies (“DTC Participants”), (2) those who maintain, either directly or indirectly, a custodial relationship with a DTC Participant (“Indirect Participants”), and (3) those banks, brokers, dealers, trust companies and others who hold interests in the units through DTC Participants or Indirect Participants, in each case who satisfy the requirements for transfers of units. DTC Participants acting on behalf of investors holding units through such participants’ accounts in DTC will follow the delivery practice applicable to securities eligible for DTC’s Same-Day Funds Settlement System. Units are credited to DTC Participants’ securities accounts following confirmation of receipt of payment.

DTC. DTC has advised USNG as follows: It is a limited purpose trust company organized under the laws of the State of New York and is a member of the Federal Reserve System, a “clearing corporation” within the meaning of the New York Uniform Commercial Code and a “clearing agency” registered pursuant to the provisions of Section 17A of the Exchange Act. DTC holds securities for DTC Participants and facilitates the clearance and settlement of transactions between DTC Participants through electronic book-entry changes in accounts of DTC Participants.

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Calculating per unit NAV

USNG’s per unit NAV is calculated by:

The Administrator calculates the per unit NAV of USNG once each NYSE Arca trading day. The per unit NAV for a particular trading day is released after 4:00 p.m. New York time. Trading during the core trading session on the NYSE Arca typically closes at 4:00 p.m. New York time. The Administrator uses the NYMEX closing price (determined at the earlier of the close of the NYMEX or 2:30 p.m. New York time) for the Futures Contracts traded on the NYMEX, but calculates or determines the value of all other USNG investments (including Futures Contracts not traded on the NYMEX, Other Natural Gas-Related Investments and Treasuries) using market quotations, if available, or other information customarily used to determine the fair value of such investments as of the earlier of the close of the NYSE Arca or 4:00 p.m. New York time, in accordance with the current Administrative Agency Agreement among BBH&Co., USNG and USCF. “Other information” customarily used in determining fair value includes information consisting of market data in the relevant market supplied by one or more third parties including, without limitation, relevant rates, prices, yields, yield curves, volatilities, spreads, correlations or other market data in the relevant market; or information of the types described above from internal sources if that information is of the same type used by USNG in the regular course of its business for the valuation of similar transactions. The information may include costs of funding, to the extent costs of funding are not and would not be a component of the other information being utilized. Third parties supplying quotations or market data may include, without limitation, dealers in the relevant markets, end-users of the relevant product, information vendors, brokers and other sources of market information.

In addition, in order to provide updated information relating to USNG for use by investors and market professionals, the NYSE Arca calculates and disseminates throughout the core trading session on each trading day an updated indicative fund value. The indicative fund value is calculated by using the prior day’s closing per unit NAV of USNG as a base and updating that value throughout the trading day to reflect changes in the most recently reported trade price for the active natural gas Futures Contracts on the NYMEX. The prices reported for those Futures Contract months are adjusted based on the prior day’s spread differential between settlement values for the relevant contract and the spot month contract. In the event that the spot month contract is also the Benchmark Futures Contract, the last sale price for that contract is not adjusted. The indicative fund value unit basis disseminated during NYSE Arca core trading session hours should not be viewed as an actual real time update of the per unit NAV, because the per unit NAV is calculated only once at the end of each trading day based upon the relevant end of day values of USNG’s investments.

The indicative fund value is disseminated on a per unit basis every 15 seconds during regular NYSE Arca core trading session hours of 9:30 a.m. New York time to 4:00 p.m. New York time. The normal trading hours of the NYMEX are 10:00 a.m. New York time to 2:30 p.m. New York time. This means that there is a gap in time at the beginning and the end of each day during which USNG’s units are traded on the NYSE Arca, but real-time NYMEX trading prices for Futures Contracts traded on the NYMEX are not available. During such gaps in time, the indicative fund value will be calculated based on the end of day price of such Futures Contracts from the NYMEX’s immediately preceding trading session. In addition, other Futures Contracts, Other Natural Gas-Related Investments and Treasuries held by USNG will be valued by the Administrator, using rates and points received from client-approved third party vendors (such as Reuters and WM Company) and advisor quotes. These investments will not be included in the indicative fund value.

The NYSE Arca disseminates the indicative fund value through the facilities of CTA/CQ High Speed Lines. In addition, the indicative fund value is published on the NYSE Arca’s website and is available through on-line information services such as Bloomberg and Reuters.

Dissemination of the indicative fund value provides additional information that is not otherwise available to the public and is useful to investors and market professionals in connection with the trading of USNG units on the NYSE Arca. Investors and market professionals are able throughout the trading day to compare the market price of USNG and the indicative fund value. If the market price of USNG units diverges significantly from the indicative fund value, market professionals will have an incentive to execute arbitrage trades. For example, if USNG appears to be trading at a discount compared to the indicative fund value, a market professional could buy USNG units on the NYSE Arca and sell short Futures Contracts. Such arbitrage trades can tighten the tracking between the market price of USNG and the indicative fund value and thus can be beneficial to all market participants.

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Creation and Redemption of Units

USNG creates and redeems units from time to time, but only in one or more Creation Baskets or Redemption Baskets. The creation and redemption of baskets are only made in exchange for delivery to USNG or the distribution by USNG of the amount of Treasuries and any cash represented by the baskets being created or redeemed, the amount of which is based on the combined NAV of the number of units included in the baskets being created or redeemed determined after 4:00 p.m. New York time on the day the order to create or redeem baskets is properly received.

Authorized Purchasers are the only persons that may place orders to create and redeem baskets. Authorized Purchasers must be (1) registered broker-dealers or other securities market participants, such as banks and other financial institutions, that are not required to register as broker-dealers to engage in securities transactions as described below, and (2) DTC Participants. To become an Authorized Purchaser, a person must enter into an Authorized Purchaser Agreement with USCF on behalf of USNG. The Authorized Purchaser Agreement provides the procedures for the creation and redemption of baskets and for the delivery of the Treasuries and any cash required for such creations and redemptions. The Authorized Purchaser Agreement and the related procedures attached thereto may be amended by USNG, without the consent of any limited partner or unitholder or Authorized Purchaser. Authorized Purchasers will pay a transaction fee of $1,000 to USNG for each order they place to create or redeem one or more baskets. Authorized Purchasers who make deposits with USNG in exchange for baskets receive no fees, commissions or other form of compensation or inducement of any kind from either USNG or USCF, and no such person will have any obligation or responsibility to USCF or USNG to effect any sale or resale of units. As of December 31, 2012, 17 Authorized Purchasers had entered into agreements with USCF on behalf of USNG. During the year ended December 31, 2012, USNG issued 1,623 Creation Baskets and redeemed 1,343 Redemption Baskets.

Certain Authorized Purchasers are expected to be capable of participating directly in the physical natural gas market and the natural gas futures market. In some cases, Authorized Purchasers or their affiliates may from time to time buy natural gas or sell natural gas or Natural Gas Interests and may profit in these instances. USCF believes that the size and operation of the natural gas market make it unlikely that an Authorized Purchaser’s direct activities in the natural gas or securities markets will significantly affect the price of natural gas, Natural Gas Interests, or the price of the units.

Each Authorized Purchaser is required to be registered as a broker-dealer under the Exchange Act and is a member in good standing with FINRA, or exempt from being or otherwise not required to be registered as a broker-dealer or a member of FINRA, and qualified to act as a broker or dealer in the states or other jurisdictions where the nature of its business so requires. Certain Authorized Purchasers may also be regulated under federal and state banking laws and regulations. Each Authorized Purchaser has its own set of rules and procedures, internal controls and information barriers as it determines is appropriate in light of its own regulatory regime.

Under the Authorized Purchaser Agreement, USCF has agreed to indemnify the Authorized Purchasers against certain liabilities, including liabilities under the Securities Act of 1933, as amended (the “Securities Act”), and to contribute to the payments the Authorized Purchasers may be required to make in respect of those liabilities.

The following description of the procedures for the creation and redemption of baskets is only a summary and an investor should refer to the relevant provisions of the LP Agreement and the form of Authorized Purchaser Agreement for more detail, each of which is incorporated by reference into this annual report on Form 10-K.

Creation Procedures

On any business day, an Authorized Purchaser may place an order with the Marketing Agent to create one or more baskets. For purposes of processing purchase and redemption orders, a “business day” means any day other than a day when any of the NYSE Arca, the NYMEX or the NYSE is closed for regular trading. Purchase orders must be placed by 12:00 p.m. New York time or the close of regular trading on the NYSE Arca, whichever is earlier. The day on which the Marketing Agent receives a valid purchase order is referred to as the purchase order date.

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By placing a purchase order, an Authorized Purchaser agrees to deposit Treasuries, cash, or a combination of Treasuries and cash, as described below. Prior to the delivery of baskets for a purchase order, the Authorized Purchaser must also have wired to the Custodian the non-refundable transaction fee due for the purchase order. Authorized Purchasers may not withdraw a creation request.

The manner by which creations are made is dictated by the terms of the Authorized Purchaser Agreement. By placing a purchase order, an Authorized Purchaser agrees to (1) deposit Treasuries, cash or a combination of Treasuries and cash with the Custodian, and (2) if required by USCF in its sole discretion, enter into or arrange for a block trade, an exchange for physical or exchange for swap, or any other over-the-counter energy transaction (through itself or a designated acceptable broker) with USNG for the purchase of a number and type of futures contracts at the closing settlement price for such contracts on the purchase order date. If an Authorized Purchaser fails to consummate (1) and (2), the order shall be cancelled. The number and type of contracts specified shall be determined by USCF, in its sole discretion, to meet USNG’s investment objective and shall be purchased as a result of the Authorized Purchaser’s purchase of units.

Determination of Required Deposits

The total deposit required to create each basket (“Creation Basket Deposit”) is the amount of Treasuries and/or cash that is in the same proportion to the total assets of USNG (net of estimated accrued but unpaid fees, expenses and other liabilities) on the purchase order date as the number of units to be created under the purchase order is in proportion to the total number of units outstanding on the purchase order dates. USCF determines, directly in its sole discretion or in consultation with the Administrator, the requirements for Treasuries and the amount of cash, including the maximum permitted remaining maturity of a Treasury and proportions of Treasury and cash that may be included in deposits to create baskets. The Marketing Agent will publish such requirements at the beginning of each business day. The amount of cash deposit required is the difference between the aggregate market value of the Treasuries required to be included in a Creation Basket Deposit as of 4:00 p.m. New York time on the date the order to purchase is properly received and the total required deposit.

Delivery of Required Deposits

An Authorized Purchaser who places a purchase order is responsible for transferring to USNG’s account with the Custodian the required amount of Treasuries and cash by the end of the third business day following the purchase order date. Upon receipt of the deposit amount, the Administrator directs DTC to credit the number of baskets ordered to the Authorized Purchaser’s DTC account on the third business day following the purchase order date. The expense and risk of delivery and ownership of Treasuries until such Treasuries have been received by the Custodian on behalf of USNG shall be borne solely by the Authorized Purchaser.

Because orders to purchase baskets must be placed by 12:00 p.m., New York time, but the total payment required to create a basket during the continuous offering period will not be determined until after 4:00 p.m. New York time on the date the purchase order is received, Authorized Purchasers will not know the total amount of the payment required to create a basket at the time they submit an irrevocable purchase order for the basket. USNG’s per unit NAV and the total amount of the payment required to create a basket could rise or fall substantially between the time an irrevocable purchase order is submitted and the time the amount of the purchase price in respect thereof is determined.

Rejection of Purchase Orders

USCF acting by itself or through the Marketing Agent shall have the absolute right but no obligation to reject a purchase order or a Creation Basket Deposit if:

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None of USCF, the Marketing Agent or the Custodian will be liable for the rejection of any purchase order or Creation Basket Deposit.

Redemption Procedures

The procedures by which an Authorized Purchaser can redeem one or more baskets mirror the procedures for the creation of baskets. On any business day, an Authorized Purchaser may place an order with the Marketing Agent to redeem one or more baskets. Redemption orders must be placed by 12:00 p.m. New York time or the close of regular trading on the NYSE Arca, whichever is earlier. A redemption order so received will be effective on the date it is received in satisfactory form by the Marketing Agent. The redemption procedures allow Authorized Purchasers to redeem baskets and do not entitle an individual unitholder to redeem any units in an amount less than a Redemption Basket, or to redeem baskets other than through an Authorized Purchaser.

By placing a redemption order, an Authorized Purchaser agrees to deliver the baskets to be redeemed through DTC’s book-entry system to USNG, as described below. Prior to the delivery of the redemption distribution for a redemption order, the Authorized Purchaser must also have wired to USNG’s account at the Custodian the non-refundable transaction fee due for the redemption order. An Authorized Purchaser may not withdraw a redemption order.

The manner by which redemptions are made is dictated by the terms of the Authorized Purchaser Agreement. By placing a redemption order, an Authorized Purchaser agrees to (1) deliver the Redemption Basket to be redeemed through DTC’s book-entry system to USNG’s account with the Custodian not later than 3:00 p.m. New York time on the third business day following the effective date of the redemption order (“Redemption Distribution Date”), and (2) if required by USCF in its sole discretion, enter into or arrange for a block trade, an exchange for physical or exchange for swap, or any other over-the-counter energy transaction (through itself or a designated acceptable broker) with USNG for the sale of a number and type of futures contracts at the closing settlement price for such contracts on the Redemption Order Date. If an Authorized Purchaser fails to consummate (1) and (2) above, the order shall be cancelled. The number and type of contracts specified shall be determined by USCF, in its sole discretion, to meet USNG’s investment objective and shall be sold as a result of the Authorized Purchaser’s sale of units.

Determination of Redemption Distribution

The redemption distribution from USNG consists of a transfer to the redeeming Authorized Purchaser of an amount of Treasuries and/or cash that is in the same proportion to the total assets of USNG (net of estimated accrued but unpaid fees, expenses and other liabilities) on the date the order to redeem is properly received as the number of units to be redeemed under the redemption order is in proportion to the total number of units outstanding on the date the order is received. USCF, directly or in consultation with the Administrator, determines the requirements for Treasuries and the amounts of cash, including the maximum permitted remaining maturity of a Treasury, and the proportions of Treasuries and cash that may be included in distributions to redeem baskets. The Marketing Agent will publish an estimate of the redemption distribution per basket as of the beginning of each business day.

Delivery of Redemption Distribution

The redemption distribution due from USNG will be delivered to the Authorized Purchaser by 3:00 p.m. New York time on the third business day following the redemption order date if, by 3:00 p.m. New York time on such third business day, USNG’s DTC account has been credited with the baskets to be redeemed. If USNG’s DTC account has not been credited with all of the baskets to be redeemed by such time, the redemption distribution will be delivered to the extent of whole baskets received. Any remainder of the redemption distribution will be delivered on the next business day to the extent of remaining whole baskets received if USNG receives the fee applicable to the extension of the redemption distribution date which USCF may, from time to time, determine and the remaining baskets to be redeemed are credited to USNG’s DTC account by 3:00 p.m. New York time on such next business day. Any further outstanding amount of the redemption order shall be cancelled. Pursuant to information from USCF, the Custodian will also be authorized to deliver the redemption distribution notwithstanding that the baskets to be redeemed are not credited to USNG’s DTC account by 3:00 p.m. New York time on the third business day following the redemption order date if the Authorized Purchaser has collateralized its obligation to deliver the baskets through DTC’s book entry-system on such terms as USCF may from time to time determine.

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Suspension or Rejection of Redemption Orders

USCF may, in its discretion, suspend the right of redemption, or postpone the redemption settlement date, (1) for any period during which the NYSE Arca or the NYMEX is closed other than customary weekend or holiday closings, or trading on the NYSE Arca or the NYMEX is suspended or restricted, (2) for any period during which an emergency exists as a result of which delivery, disposal or evaluation of Treasuries is not reasonably practicable, or (3) for such other period as USCF determines to be necessary for the protection of the limited partners or unitholders. For example, USCF may determine that it is necessary to suspend redemptions to allow for the orderly liquidation of USNG’s assets at an appropriate value to fund a redemption. If USCF has difficulty liquidating its positions, e.g., because of a market disruption event in the futures markets, a suspension of trading by the exchange where the futures contracts are listed or an unanticipated delay in the liquidation of a position in an over-the-counter contract, it may be appropriate to suspend redemptions until such time as such circumstances are rectified. None of USCF, the Marketing Agent, the Administrator, or the Custodian will be liable to any person or in any way for any loss or damages that may result from any such suspension or postponement.

Redemption orders must be made in whole baskets. USCF will reject a redemption order if the order is not in proper form as described in the Authorized Purchaser Agreement or if the fulfillment of the order, in the opinion of its counsel, might be unlawful. USCF may also reject a redemption order if the number of units being redeemed would reduce the remaining outstanding units to 100,000 units (i.e., one basket) or less.

Creation and Redemption Transaction Fee

To compensate USNG for its expenses in connection with the creation and redemption of baskets, an Authorized Purchaser is required to pay a transaction fee to USNG of $1,000 per order to create or redeem baskets, regardless of the number of baskets in such order. An order may include multiple baskets. The transaction fee may be reduced, increased or otherwise changed by USCF. USCF shall notify DTC of any change in the transaction fee and will not implement any increase in the fee for the redemption of baskets until 30 days after the date of the notice.

Tax Responsibility

Authorized Purchasers are responsible for any transfer tax, sales or use tax, stamp tax, recording tax, value added tax or similar tax or governmental charge applicable to the creation or redemption of baskets, regardless of whether or not such tax or charge is imposed directly on the Authorized Purchaser, and agree to indemnify USCF and USNG if they are required by law to pay any such tax, together with any applicable penalties, additions to tax and interest thereon.

Secondary Market Transactions

As noted, USNG creates and redeems units from time to time, but only in one or more Creation Baskets or Redemption Baskets. The creation and redemption of baskets are only made in exchange for delivery to USNG or the distribution by USNG of the amount of Treasuries and cash represented by the baskets being created or redeemed, the amount of which will be based on the aggregate NAV of the number of units included in the baskets being created or redeemed determined on the day the order to create or redeem baskets is properly received.

As discussed above, Authorized Purchasers are the only persons that may place orders to create and redeem baskets. Authorized Purchasers must be registered broker-dealers or other securities market participants, such as banks and other financial institutions that are not required to register as broker-dealers to engage in securities transactions. An Authorized Purchaser is under no obligation to create or redeem baskets, and an Authorized Purchaser is under no obligation to offer to the public units of any baskets it does create. Authorized Purchasers that do offer to the public units from the baskets they create will do so at per-unit offering prices that are expected to reflect, among other factors, the trading price of the units on the NYSE Arca, the NAV of USNG at the time the Authorized Purchaser purchased the Creation Baskets and the per unit NAV of the units at the time of the offer of the units to the public, the supply of and demand for units at the time of sale, and the liquidity of the Futures Contract market and the market for Other Natural Gas-Related Investments. The prices of units offered by Authorized Purchasers are expected to fall between USNG’s per unit NAV and the trading price of the units on the NYSE Arca at the time of sale. Units initially comprising the same basket but offered by Authorized Purchasers to the public at different times may have different offering prices. An order for one or more baskets may be placed by an Authorized Purchaser on behalf of multiple clients. Authorized Purchasers who make deposits with USNG in exchange for baskets receive no fees, commissions or other form of compensation or inducement of any kind from either USNG or USCF, and no such person has any obligation or responsibility to USCF or USNG to effect any sale or resale of units. Units trade in the secondary market on the NYSE Arca. Units may trade in the secondary market at prices that are lower or higher relative to their per unit NAV. The amount of the discount or premium in the trading price relative to the per unit NAV may be influenced by various factors, including the number of investors who seek to purchase or sell units in the secondary market and the liquidity of the Futures Contracts market and the market for Other Natural Gas-Related Investments. While the units trade during the core trading session on the NYSE Arca until 4:00 p.m. New York time, liquidity in the market for Futures Contracts and Other Natural Gas-Related Investments may be reduced after the close of the NYMEX at 2:30 p.m. New York time. As a result, during this time, trading spreads, and the resulting premium or discount, on the units may widen.

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Investments

USCF causes USNG to transfer the proceeds from the sale of Creation Baskets to the Custodian or other custodian for trading activities. USCF will invest USNG’s assets in Futures Contracts and Other Natural Gas-Related Investments and investments in Treasuries, cash and/or cash equivalents. When USNG purchases a Futures Contract and certain exchange-traded Other Natural Gas-Related Investments, USNG is required to deposit 5% to 30% with the selling FCM on behalf of the exchange a portion of the value of the contract or other interest as security to ensure payment for the obligation under Natural Gas Interests at maturity. This deposit is known as initial margin. Counterparties in transactions in over-the-counter Natural Gas Interests will generally impose similar collateral requirements on USNG. USCF will invest the assets that remain after margin and collateral are posted in Treasuries, cash and/or cash equivalents subject to these margin and collateral requirements. USCF has sole authority to determine the percentage of assets that are:

Ongoing margin and collateral payments will generally be required for both exchange-traded and over-the-counter Natural Gas Interests based on changes in the value of the Natural Gas Interests. Furthermore, ongoing collateral requirements with respect to over-the-counter Natural Gas Interests are negotiated by the parties, and may be affected by overall market volatility, volatility of the underlying commodity or index, the ability of the counterparty to hedge its exposure under a Natural Gas Interest and each party’s creditworthiness. In light of the differing requirements for initial payments under exchange-traded and over-the-counter Natural Gas Interests and the fluctuating nature of ongoing margin and collateral payments, it is not possible to estimate what portion of USNG’s assets will be posted as margin or collateral at any given time. The Treasuries, cash and cash equivalents held by USNG will constitute reserves that will be available to meet ongoing margin and collateral requirements. All interest income will be used for USNG’s benefit.

A FCM, counterparty, government agency or commodity exchange could increase margin or collateral requirements applicable to USNG to hold trading positions at any time. Moreover, margin is merely a security deposit and has no bearing on the profit or loss potential for any positions held.

The assets of USNG posted as margin for Futures Contracts are held in segregated accounts pursuant to the CEA and CFTC regulations.

USNG must post both collateral and independent amounts to its swap counterparties. The amount of collateral USNG posts changes according to the amounts owed by USNG to its counterparty on a given swap transaction, while independent amounts are fixed amounts posted by USNG at the start of a swap transaction. Collateral and independent amounts posted to swap counterparties are held by a third party custodian.

The Commodity Interest Markets

General

The CEA governs the regulation of commodity interest transactions, markets and intermediaries. The CEA provides for varying degrees of regulation of commodity interest transactions depending upon: (1) the type of instrument being traded (e.g., contracts for future delivery, options, swaps or spot contracts), (2) the type of commodity underlying the instrument (distinctions are made between instruments based on agricultural commodities, energy and metals commodities and financial commodities), (3) the nature of the parties to the transaction (retail, eligible contract participant, or eligible commercial entity), (4) whether the transaction is entered into on a principal-to-principal or intermediated basis, (5) the type of market on which the transaction occurs, and (6) whether the transaction is subject to clearing through a clearing organization.

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The offer and sale of units of USNG, as well as units of each of the Related Public Funds, is registered under the Securities Act. USNG and the Related Public Funds are subject to the requirements of the Securities Act, the Exchange Act and the rules and regulations adopted thereunder, as administered by the Securities and Exchange Commission (the “SEC”). Firms’ participation in the distribution of units are regulated as described above, as well as by the self regulatory association, FINRA.

Futures Contracts

A futures contract is a standardized contract traded on, or subject to the rules of, an exchange that calls for the future delivery of a specified quantity and type of a commodity at a specified time and place. Futures contracts are traded on a wide variety of commodities, including agricultural products, bonds, stock indices, interest rates, currencies, energy and metals. The size and terms of futures contracts on a particular commodity are identical and are not subject to any negotiation, other than with respect to price and the number of contracts traded between the buyer and seller.

The contractual obligations of a buyer or seller may generally be satisfied by taking or making physical delivery of the underlying commodity or by making an offsetting sale or purchase of an identical futures contract on the same or linked exchange before the designated date of delivery. The difference between the price at which the futures contract is purchased or sold and the price paid for the offsetting sale or purchase, after allowance for brokerage commissions, constitutes the profit or loss to the trader. Some futures contracts, such as stock index contracts, settle in cash (reflecting the difference between the contract purchase/sale price and the contract settlement price) rather than by delivery of the underlying commodity.

In market terminology, a trader who purchases a futures contract is long in the market and a trader who sells a futures contract is short in the market. Before a trader closes out his long or short position by an offsetting sale or purchase, his outstanding contracts are known as open trades or open positions. The aggregate amount of open positions held by traders in a particular contract is referred to as the open interest in such contract.

Forward Contracts

A forward contract is a contractual obligation to purchase or sell a specified quantity of a commodity at or before a specified date in the future at a specified price and, therefore, is economically similar to a futures contract. Unlike futures contracts, however, forward contracts are typically traded in the over-the-counter markets and are not standardized contracts. Forward contracts for a given commodity are generally available for various amounts and maturities and are subject to individual negotiation between the parties involved. Moreover, generally there is no direct means of offsetting or closing out a forward contract by taking an offsetting position as one would a futures contract on a U.S. exchange. If a trader desires to close out a forward contract position, he generally will establish an opposite position in the contract but will settle and recognize the profit or loss on both positions simultaneously on the delivery date. Thus, unlike in the futures contract market where a trader who has offset positions will recognize profit or loss immediately, in the forward market a trader with a position that has been offset at a profit will generally not receive such profit until the delivery date, and likewise a trader with a position that has been offset at a loss will generally not have to pay money until the delivery date. In recent years, however, the terms of forward contracts have become more standardized, and in some instances such contracts now provide a right of offset or cash settlement as an alternative to making or taking delivery of the underlying commodity.

In general, the CFTC does not regulate the interbank and forward foreign currency markets with respect to transactions in contracts between certain sophisticated counterparties such as USNG or between certain regulated institutions and retail investors. Although U.S. banks are regulated in various ways by the Federal Reserve Board, the Comptroller of the Currency and other U.S. federal and state banking officials, banking authorities do not regulate the forward markets to the same extent that the swap markets will be regulated by the CFTC once the Dodd-Frank Act is fully implemented. At a minimum, over-the-counter currency forwards, options and swaps will be subject to heightened recordkeeping, reporting and business conduct standards.

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On November 16, 2012, the Secretary of the Treasury issued a final determination that exempts both foreign exchange swaps and foreign exchange forwards from the definition of “swap” and, by extension, additional regulatory requirements (such as clearing and margin). The final determination does not extend to other foreign exchange derivatives, such as foreign exchange options, currency swaps and non-deliverable forwards.

While the U.S. government does not currently impose any restrictions on the movements of currencies, it could choose to do so. The imposition or relaxation of exchange controls in various jurisdictions could significantly affect the market for that and other jurisdictions’ currencies. Trading in the interbank market also exposes USNG to a risk of default since the failure of a bank with which USNG had entered into a forward contract would likely result in a default and thus possibly substantial losses to USNG.

Options on Futures Contracts

Options on futures contracts are standardized contracts traded on an exchange. An option on a futures contract gives the buyer of the option the right, but not the obligation, to take a position at a specified price (the striking, strike, or exercise price) in the underlying futures contract or underlying interest. The buyer of a call option acquires the right, but not the obligation, to purchase or take a long position in the underlying interest, and the buyer of a put option acquires the right, but not the obligation, to sell or take a short position in the underlying interest.

The seller, or writer, of an option is obligated to take a position in the underlying interest at a specified price opposite to the option buyer if the option is exercised. The seller of a call option must stand ready to take a short position in the underlying interest at the strike price if the buyer should exercise the option. The seller of a put option, on the other hand, must stand ready to take a long position in the underlying interest at the strike price.

A call option is said to be in-the-money if the strike price is below current market levels and out-of-the-money if the strike price is above current market levels. Conversely, a put option is said to be in-the-money if the strike price is above the current market levels and out-of-the-money if the strike price is below current market levels.

Options have limited life spans, usually tied to the delivery or settlement date of the underlying interest. Some options, however, expire significantly in advance of such date. The purchase price of an option is referred to as its premium, which consists of its intrinsic value (which is related to the underlying market value) plus its time value. As an option nears its expiration date, the time value shrinks and the market and intrinsic values move into parity. An option that is out-of-the-money and not offset by the time it expires becomes worthless. On certain exchanges, in-the-money options are automatically exercised on their expiration date, but on others unexercised options simply become worthless after their expiration date.

Regardless of how much the market swings, the most an option buyer can lose is the option premium. The option buyer deposits his premium with his broker, and the money goes to the option seller. Option sellers, on the other hand, face risks similar to participants in the futures markets. For example, since the seller of a call option is assigned a short futures position if the option is exercised, his risk is the same as someone who initially sold a futures contract. Because no one can predict exactly how the market will move, the option seller posts margin to demonstrate his ability to meet any potential contractual obligations.

Options on Forward Contracts or Commodities

Options on forward contracts or commodities operate in a manner similar to options on futures contracts. An option on a forward contract or commodity gives the buyer of the option the right, but not the obligation, to take a position at a specified price in the underlying forward contract or commodity. However, unlike options on futures contracts, options on forward contracts or on commodities are individually negotiated contracts between counterparties and are typically traded in the over-the-counter market. Therefore, options on forward contracts and physical commodities possess many of the same characteristics of forward contracts with respect to offsetting positions and credit risk that are described above.

Swap Contracts

Swap transactions generally involve contracts between two parties to exchange a stream of payments computed by reference to a notional amount and the price of the asset that is the subject of the swap. Swap contracts are principally traded off-exchange, although certain swap contracts are also being traded in electronic trading facilities and cleared through clearing organizations.

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Swaps are usually entered into on a net basis, that is, the two payment streams are netted out in a cash settlement on the payment date or dates specified in the agreement, with the parties receiving or paying, as the case may be, only the net amount of the two payments. Swaps do not generally involve the delivery of underlying assets or principal. Accordingly, the risk of loss with respect to swaps is generally limited to the net amount of payments that the party is contractually obligated to make. In some swap transactions one or both parties may require collateral deposits from the counterparty to support that counterparty’s obligation under the swap agreement. If the counterparty to such a swap defaults, the risk of loss consists of the net amount of payments that the party is contractually entitled to receive less any collateral deposits it is holding.

Some swap transactions are cleared through central counterparties. These transactions, known as cleared swaps, involve two counterparties first agreeing to the terms of a swap transaction, then submitting the transaction to a clearing house that acts as the central counterparty. Once accepted by the clearing house, the original swap transaction is novated and the central counterparty becomes the counterparty to a trade with each of the original parties based upon the trade terms determined in the original transaction. In this manner each individual swap counterparty reduces its risk of loss due to counterparty nonperformance because the clearing house acts as the counterparty to each transaction.

“Swap” Transactions

The Dodd-Frank Act imposes new regulatory requirements on certain “swap” transactions that USNG is authorized to engage in that may ultimately impact the ability of USNG to meet its investment objective. On August 13, 2012, the CFTC and the SEC published joint final rules defining the terms “swap” and “security-based swaps.” The term “swap” is broadly defined to include various types of over-the-counter derivatives, including swaps and options. The effective date of these final rules was October 12, 2012.

The Dodd-Frank Act requires that certain transactions ultimately falling within the definition of “swap” be executed on organized exchanges or “swap execution facilities” and cleared through regulated clearing organizations (which are referred to in the Dodd-Frank Act as “derivative clearing organizations” (“DCOs”)), if the CFTC mandates the central clearing of a particular contract. On November 28, 2012, the CFTC issued its final clearing determination requiring that certain credit default swaps and interest rate swaps be cleared by registered DCOs. This is the CFTC’s first clearing determination under the Dodd-Frank Act and became effective on February 11, 2013. Determination on other types of swaps are expected in the future, and, when finalized, could require USNG to centrally clear certain over-the-counter instruments presently entered into and settled on a bi-lateral basis. If a swap is required to be cleared, the initial margin will be set by the clearing organizations, subject to certain regulatory requirements and guidelines. Initial and variation margin requirements for swap dealers and major swap participants who enter into uncleared swaps and capital requirements for swap dealers and major swap participants who enter into both cleared and uncleared trades will be set by the CFTC, the SEC or the applicable “Prudential Regulator.” On May 23, 2012, the CFTC published final regulations, which became effective as of July 23, 2012, to determine which entities will be regulated as “swap dealers” and “major swap participants” and thus have to comply with these capital and margin requirements (as well as a multitude of other requirements under the Dodd-Frank Act). Most of the requirements became effective on October 12, 2012 when additional final rules defining the terms “swap,” “security-based swap” and “mixed swap” became effective. However, on October 11, 2012 and October 12, 2012, the CFTC issued several no-action letters and interpretative guidance which delayed much of the implementation of these requirements from October 12, 2012 until December 31, 2012. Increased regulation of, and the imposition of additional costs on, swap transactions could have an adverse effect on USNG by, for example, reducing the size of and therefore liquidity in the derivatives market, increasing transaction costs and decreasing the ability to customize derivative transactions.

On February 7, 2012, the CFTC published a rule requiring each FCM and DCO to segregate cleared swaps and related collateral posted by a customer of the FCM from the assets of the FCM or DCO, although such property can be commingled with the property of other cleared swaps customers of the FCM or DCO. This rule addresses losses incurred by a DCO in a so-called “double default” scenario in which a customer of a FCM defaults in its obligations to the FCM and the FCM, in turn, defaults in its obligations to the DCO. Under this scenario, the DCO can only access the collateral attributable to other customers of the DCO whose cleared swap positions are in a loss position following the primary customer’s default. This rule became effective on November 8, 2012. Some market participants have expressed concern that the requirements of this segregation rule may result in higher initial margins or higher fees. USNG does not anticipate any impact to its operations in order to meet the requirements of the new rule.

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Additionally, the CFTC published rules on February 17, 2012 and April 3, 2012 that require “swap dealers” and “major swap participants” to: 1) adhere to business conduct standards, 2) implement policies and procedures to ensure compliance with the CEA and 3) maintain records of such compliance. These new requirements may impact the documentation requirements for both cleared and non-cleared swaps and cause swap dealers and major swap participants to face increased compliance costs that, in turn, may be passed along to counterparties (such as USNG) in the form of higher fees and expenses related to trading swaps.

On February 24, 2012, the CFTC amended certain disclosure obligations to require that the operator of a commodity pool that invests in swaps include standardized swap risk disclosures in the pool’s disclosure documents by December 31, 2012.

On December 5, 2012, the CFTC’s Division of Market Oversight issued a letter providing swap dealers with time-limited no-action relief from swap data reporting obligations with respect to equity swaps, foreign exchange swaps and other commodity swaps. For these asset classes, the letter provides swap dealers with reporting relief (i) with respect to real-time price reporting and regular swap reporting (under Part 43 and Part 45 of the CFTC’s regulations, respectively), until February 28, 2013, and (ii) historical swap reporting requirements (under Part 46 of the CFTC’s regulations) until March 30, 2013.

On December 21, 2012, the CFTC’s Division of Market Oversight issued two letters providing certain swap dealers with time-limited no-action relief from some swap data reporting obligations. One letter provides relief from reporting requirements for branches of swap dealers located in emerging markets who encounter technical difficulties in complying with the reporting rules. The letter also provides that swap dealers may delay reporting compliance for certain complex and exotic swaps until April 30, 2012.

Under a second letter, all swap dealers have until April 10, 2013 to report certain information about their counterparties, including: status as a major swap participant, a financial entity, a U.S. person or a commercial end-user.

On December 18, 2012, the CFTC deferred the compliance date for many of the Dodd-Frank Act’s external business conduct standards from December 31, 2012 to May 1, 2013, and for some requirements to July 1, 2013, providing swap dealers an additional four to six months from the original compliance date.

Regulation

Futures exchanges in the United States are subject to varying degrees of regulation under the CEA depending on whether such exchange is a designated contract market, exempt board of trade or electronic trading facility. Clearing organizations are also subject to the CEA and the rules and regulations adopted thereunder and administered by the CFTC. The CFTC is the governmental agency charged with responsibility for regulation of futures exchanges and commodity interest trading conducted on those exchanges. The CFTC’s function is to implement the CEA’s objectives of preventing price manipulation and excessive speculation and promoting orderly and efficient commodity interest markets. In addition, the various exchanges and clearing organizations themselves exercise regulatory and supervisory authority over their member firms.

The CFTC also regulates the activities of “commodity trading advisors” and “commodity pool operators” and the CFTC has adopted regulations with respect to certain of such persons’ activities. Pursuant to its authority, the CFTC requires a CPO, such as USCF, to keep accurate, current and orderly records with respect to each pool it operates. The CFTC may suspend, modify or terminate the registration of any registrant for failure to comply with CFTC rules or regulations. Suspension, restriction or termination of USCF’s registration as a CPO would prevent it, until such time (if any) as such registration were to be reinstated, from managing, and might result in the termination of, USNG or the Related Public Funds.

The CEA also gives the states certain powers to enforce its provisions and the regulations of the CFTC.

Under certain circumstances, the CEA grants unitholders the right to institute a reparations proceeding before the CFTC against USCF (as a registered commodity pool operator), as well as those of their respective employees who are required to be registered under the CEA. Unitholders may also be able to maintain a private right of action for certain violations of the CEA.

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Pursuant to authority in the CEA, the NFA has been formed and registered with the CFTC as a registered futures association. The NFA is the only self regulatory association for commodities professionals other than the exchanges. As such, the NFA promulgates rules governing the conduct of commodity professionals and disciplines those professionals that do not comply with such standards. The CFTC has delegated to the NFA responsibility for the registration of commodity pool operation. USCF is a member of the NFA. As a member of the NFA, USCF is subject to NFA standards relating to fair trade practices, financial condition and consumer protection. The CFTC is prohibited by statute from regulating trading on foreign commodity exchanges and markets.

The CEA requires all FCMs, such as USNG’s clearing brokers, to meet and maintain specified fitness and financial requirements, to segregate customer funds from proprietary funds and account separately for all customers’ funds and positions, and to maintain specified books and records open to inspection by the staff of the CFTC. The CFTC has similar authority over introducing brokers, or persons who solicit or accept orders for commodity interest trades but who do not accept margin deposits for the execution of trades. The CEA authorizes the CFTC to regulate trading by FCMs and by their officers and directors, permits the CFTC to require action by exchanges in the event of market emergencies, and establishes an administrative procedure under which customers may institute complaints for damages arising from alleged violations of the CEA. The CEA also gives the states powers to enforce its provisions and the regulations of the CFTC.

The regulations of the CFTC and the NFA prohibit any representation by a person registered with the CFTC or by any member of the NFA, that registration with the CFTC, or membership in the NFA, in any respect indicates that the CFTC or the NFA, as the case may be, has approved or endorsed that person or that person’s trading program or objectives. The registrations and memberships of the parties described in this summary must not be considered as constituting any such approval or endorsement. Likewise, no futures exchange has given or will give any similar approval or endorsement.

On November 14, 2012, the CFTC proposed new regulations that would require enhanced customer protections, risk management programs, internal monitoring and controls, capital and liquidity standards, customer disclosures and auditing and examination programs for FCMs. The proposed rules are intended to afford greater assurances to market participants that customer segregated funds and secured amounts are protected, customers are provided with appropriate notice of the risks of futures trading and of the FCMs with which they may choose to do business, FCMs are monitoring and managing risks in a robust manner, the capital and liquidity of FCMs are strengthened to safeguard the continued operations and the auditing and examination programs of the CFTC and the self-regulatory organizations are monitoring the activities of FCMs in a thorough manner. The final regulations have not yet been adopted.

USNG’s investors are afforded prescribed rights for reparations under the CEA against USCF (as a registered commodity pool operator), as well as its respective employees who are required to be registered under the CEA. Investors may also be able to maintain a private right of action for violations of the CEA. The CFTC has adopted rules implementing the reparation provisions of the CEA, which provide that any person may file a complaint for a reparations award with the CFTC for violation of the CEA against a floor broker or a FCM, introducing broker, commodity trading advisor, CPO and their respective associated persons.

The regulation of commodity interest trading in the United States and other countries is an evolving area of the law, as exemplified by the various discussions of the Dodd-Frank Act. The various statements made in this summary are subject to modification by legislative action and changes in the rules and regulations of the CFTC, the NFA, the futures exchanges, clearing organizations and other regulatory bodies.

Futures Contracts and Position Limits

The CFTC is prohibited by statute from regulating trading on non-U.S. futures exchanges and markets. The CFTC, however, has adopted regulations relating to the marketing of non-U.S. futures contracts in the United States. These regulations permit certain contracts traded on non-U.S. exchanges to be offered and sold in the United States.

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In October 2011, the CFTC finalized the Position Limit Rules, which were scheduled to become effective on October 12, 2012. However, on September 28, 2012, the United States District Court for the District of Columbia vacated these regulations on the basis of ambiguities in the provisions of the CEA (as modified by the Dodd-Frank Act) upon which the regulations were based. In its September 28, 2012, the court remanded the Position Limit Rules to the CFTC with instructions to use its expertise and experience to resolve the ambiguities in the statute. On November 15, 2012, the CFTC indicated that it will move forward with an appeal of the District Court’s decision to vacate the Position Limit Rules. At this time, it is not possible to predict how the CFTC’s appeal could affect USNG, but it may be substantial and adverse. Furthermore, until such time as the appeal is resolved or, if applicable revisions to the Position Limit Rules are proposed and adopted, the regulatory architecture in effect prior to the enactment of the Position Limit Rules will govern transactions in commodities and related derivatives. As a result, USNG may be limited with respect to the size of its investments in any commodities subject to these limits. Finally, subject to certain narrow exceptions, the vacated Position Limit Rules would have required the aggregation, for purposes of the position limits, of all positions in the 28 Referenced Contracts held by a single entity and its affiliates, regardless of whether such position existed on U.S. futures exchanges, non-U.S. futures exchanges, in cleared swaps or in over-the-counter swaps. The CFTC is presently considering new aggregation rules, under a rulemaking proposal that is distinct from the Position Limit Rules. At this time, it is unclear how any modified aggregation rules may affect USNG, but it may be substantial and adverse. By way of example, the aggregation rules in combination with any potential revised Position Limit Rules may negatively impact the ability of USNG to meet its investment objectives through limits that may inhibit USCF’s ability to sell additional Creation Baskets of USNG.

Based on its current understanding of the final position limit regulations, USCF does not anticipate significant negative impact on the ability of USNG to achieve its investment objective.

Commodity Margin

Original or initial margin is the minimum amount of funds that must be deposited by a commodity interest trader with the trader’s broker to initiate and maintain an open position in futures contracts. Maintenance margin is the amount (generally less than the original margin) to which a trader’s account may decline before he must deliver additional margin. A margin deposit is like a cash performance bond. It helps assure the trader’s performance of the futures contracts that he or she purchases or sells. Futures contracts are customarily bought and sold on initial margin that represents a very small percentage (ranging upward from less than 5%) of the aggregate purchase or sales price of the contract. Because of such low margin requirements, price fluctuations occurring in the futures markets may create profits and losses that, in relation to the amount invested, are greater than are customary in other forms of investment or speculation. As discussed below, adverse price changes in the futures contract may result in margin requirements that greatly exceed the initial margin. In addition, the amount of margin required in connection with a particular futures contract is set from time to time by the exchange on which the contract is traded and may be modified from time to time by the exchange during the term of the contract.

Brokerage firms, such as USNG’s clearing brokers, carrying accounts for traders in commodity interest contracts may not accept lower, and generally require higher, amounts of margin as a matter of policy to further protect themselves. The clearing brokers require USNG to make margin deposits equal to exchange minimum levels for all commodity interest contracts. This requirement may be altered from time to time in the clearing brokers’ discretion.

Regulators have not yet finalized the Dodd-Frank Act rules regarding initial margin levels for over-the-counter derivatives. It is possible that such levels may be higher than those for futures contracts. Also, initial margin requirements for non-cleared swaps that will be subject to higher margin requirements than cleared swaps. And, under pending rule proposals, USNG may be required to post, but not be entitled to receive, initial and variation margin in respect of non-cleared swaps. Until such time as the regulators finalize these margin rules, trading in the over-the-counter markets where no clearing facility is provided generally will not require margin per se. Rather, it will involve the extension of credit between counterparties that is secured by transfers of credit support and/or independent amounts. Credit support is transferred between counterparties in respect of the open over-the-counter derivatives entered into between them, while independent amounts are fixed amounts posted by one or both counterparties at the execution of a particular over-the-counter transaction.

When a trader purchases an option, there is no margin requirement; however, the option premium must be paid in full. When a trader sells an option, on the other hand, he or she is required to deposit margin in an amount determined by the margin requirements established for the underlying interest and, in addition, an amount substantially equal to the current premium for the option. The margin requirements imposed on the selling of options, although adjusted to reflect the probability that out-of-the-money options will not be exercised, can in fact be higher than those imposed in dealing in the futures markets directly. Complicated margin requirements apply to spreads and conversions, which are complex trading strategies in which a trader acquires a mixture of options positions and positions in the underlying interest.

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Margin requirements are computed each day by a trader’s clearing broker. When the market value of a particular open commodity interest position changes to a point where the margin on deposit does not satisfy maintenance margin requirements, a margin call is made by the broker. If the margin call is not met within a reasonable time, the broker may close out the trader’s position. With respect to USNG’s trading, USNG (and not its investors personally) is subject to margin calls.

Finally, many major U.S. exchanges have passed certain cross margining arrangements involving procedures pursuant to which the futures and options positions held in an account would, in the case of some accounts, be aggregated and margin requirements would be assessed on a portfolio basis, measuring the total risk of the combined positions.

SEC Reports

USNG makes available, free of charge, on its website, its annual reports on Form 10-K, its quarterly reports on Form 10-Q, its current reports on Form 8-K and amendments to these reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after these forms are filed with, or furnished to, the SEC. These reports are also available from the SEC though its website at: www.sec.gov.

CFTC Reports

USNG also makes available its monthly reports and its annual reports required to be prepared and filed with the NFA under the CFTC regulations.

Intellectual Property

USCF owns trademark registrations for UNITED STATES NATURAL GAS FUND (U.S. Reg. No. 3407494) for “fund investment services in the field of natural gas futures contracts, cash-settled options on natural gas futures contracts, forward contracts for natural gas, over-the-counter transactions based on the price of natural gas, and indices based on the foregoing,” in use since April 18, 2007, UNG UNITED STATES NATURAL GAS FUND, LP (and Flame Design) (U.S. Reg. No. 3683574) for “fund investment services in the field of natural gas futures contracts, cash-settled options on natural gas futures contracts, forward contracts for natural gas, over-the-counter transactions based on the price of natural gas, and indices based on the foregoing,” in use since April 18, 2007 and UNG UNITED STATES NATURAL GAS FUND, LP (and Flame Design), S.N. 85592277 in use since September 4, 2012. USNG relies upon these trademarks through which it markets its services and strives to build and maintain brand recognition in the market and among current and potential investors. So long as USNG continues to use these trademarks to identify its services, without challenge from any third party, and properly maintains and renews the trademark registrations under applicable laws, rules and regulations, it will continue to have indefinite protection for these trademarks under current laws, rules and regulations. USCF has been granted two patents Nos. 7,739,186 and 8,019,675, for systems and methods for an exchange-traded fund (ETF) that tracks the price of one or more commodities.

Item 1A.  Risk Factors.

The risk factors should be read in connection with the other information included in this annual report on Form 10-K, including Management’s Discussion and Analysis of Financial Condition and Results of Operations and USNG’s financial statements and the related notes.

Risks Associated With Investing Directly or Indirectly in Natural Gas

Investing in Natural Gas Interests subjects USNG to the risks of the natural gas industry and this could result in large fluctuations in the price of USNG’s units.

USNG is subject to the risks and hazards of the natural gas industry because it invests in Natural Gas Interests. The risks and hazards that are inherent in the natural gas industry may cause the price of natural gas to widely fluctuate. If the changes in percentage terms of USNG’s units accurately track the changes in percentage terms of the Benchmark Futures Contract or the spot price of natural gas, then the price of its units may also fluctuate. The exploration for, and production of, natural gas are uncertain processes with many risks. The cost of drilling, completing and operating wells for natural gas is often uncertain, and a number of factors can delay or prevent drilling operations or production of natural gas, including:

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Natural gas transmission, distribution, gathering, and processing activities involve numerous risks that may affect the price of natural gas.

There are a variety of hazards inherent in natural gas transmission, distribution, gathering, and processing, such as leaks, explosions, pollution, release of toxic substances, adverse weather conditions (such as hurricanes and flooding), pipeline failure, abnormal pressures, uncontrollable flows of natural gas, scheduled and unscheduled maintenance, physical damage to the gathering or transportation system, and other hazards which could affect the price of natural gas. To the extent these hazards limit the supply or delivery of natural gas, natural gas prices will increase.

The price of natural gas may fluctuate on a seasonal and quarterly basis and this would result in fluctuations in the price of USNG’s units.

Natural gas prices fluctuate seasonally. For example, in some parts of the United States and other markets, the natural gas demand for power peaks during the cold winter months, with market prices peaking at that time. As a result, in the future, the overall price of natural gas may fluctuate substantially on a seasonal and quarterly basis and thus make consecutive period to period comparisons less relevant.

Natural gas transmission and storage operations are subject to government regulations and rate proceedings which could have an impact on the price of natural gas.

Natural gas transmission and storage operations in North America are subject to regulation and oversight by the Federal Energy Regulatory Commission, various state regulatory agencies, and Canadian regulatory authorities. These regulatory bodies have the authority to effect rate settlements on natural gas storage, transmission and distribution services. As a consequence, the price of natural gas may be affected by a change in the rate settlements effected by one or more of these regulatory bodies.

Daily changes in USNG’s per unit NAV may not correlate with daily changes in the price of the Benchmark Futures Contract. If this were to occur, investors may not be able to effectively use USNG as a way to hedge against natural gas-related losses or as a way to indirectly invest in natural gas.

USCF endeavors to invest USNG’s assets as fully as possible in short-term Futures Contracts and Other Natural Gas-Related Investments so that the daily changes in percentage terms of the per unit NAV closely correlate with the daily changes in percentage terms in the price of the Benchmark Futures Contract. However, daily changes in USNG’s per unit NAV may not correlate with the daily changes in the price of the Benchmark Futures Contract for several reasons as set forth below:

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If daily changes in USNG’s per unit NAV do not correlate with daily changes in the price of the Benchmark Futures Contract, then investing in USNG may not be an effective way to hedge against natural gas-related losses or indirectly invest in natural gas.

The Benchmark Futures Contract may not correlate with the spot price of natural gas and this could cause changes in the price of the units to substantially vary from the changes in the spot price of natural gas. If this were to occur, then investors may not be able to effectively use USNG as a way to hedge against natural gas-related losses or as a way to indirectly invest in natural gas. In addition, the price relationship between the near month contract and the next month contract that compose the Benchmark Futures Contract will vary and may impact both the total return over time of USNG’s NAV, as well as the degree to which its total return tracks other natural gas price indices’ total returns.

When using the Benchmark Futures Contract as a strategy to track the spot price of natural gas, at best the correlation between changes in prices of such Natural Gas Interests and the spot price of natural gas can be only approximate. The degree of imperfection of correlation depends upon circumstances such as variations in the speculative natural gas market, supply of and demand for such Natural Gas Interests and technical influences in futures trading. If there is a weak correlation between the Natural Gas Interests and the spot price of natural gas, then even in situations where there is also tracking among the price of units, the per unit NAV of such units and Natural Gas Interests, the price of units may not accurately track the spot price of natural gas and investors may not be able to effectively use USNG as a way to hedge the risk of losses in their natural gas-related transactions or as a way to indirectly invest in natural gas.

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Backwardation and contango may increase USNG’s tracking error and/or negatively impact total return.

The design of USNG’s Benchmark Futures Contract is such that every month it begins by using the near month contract to expire until the near month contract is within two weeks of expiration, when, over a four-day period, it transitions to the next month contract to expire as its benchmark contract and keeps that contract as its benchmark until it becomes the near month contract and close to expiration. In the event of a natural gas futures market where near month contracts trade at a higher price than next month to expire contracts, a situation described as “backwardation” in the futures market, then absent the impact of the overall movement in natural gas prices the value of the benchmark contract would tend to rise as it approaches expiration. As a result, the total return of the Benchmark Futures Contract would tend to track higher. Conversely, in the event of a natural gas futures market where near month contracts trade at a lower price than next month contracts, a situation described as “contango” in the futures market, then absent the impact of the overall movement in natural gas prices the value of the Benchmark Futures Contract would tend to decline as it approaches expiration. As a result the total return of the Benchmark Futures Contract would tend to track lower. When compared to total return of other price indices, such as the spot price of natural gas, the impact of backwardation and contango may lead the total return of USNG’s per unit NAV to vary significantly. In the event of a prolonged period of contango, and absent the impact of rising or falling natural gas prices, this could have a significant negative impact on USNG’s NAV and total return. See “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations” in this annual report on Form 10-K for a discussion of the potential effects of contango and backwardation.

USNG may experience a loss if it is required to sell Treasuries at a price lower than the price at which they were acquired.

The value of Treasuries generally moves inversely with movements in interest rates. If USNG is required to sell Treasuries at a price lower than the price at which they were acquired, USNG will experience a loss. This loss may adversely impact the price of the units and may decrease the correlation among the price of units, the NAV of units, the price of the Benchmark Futures Contract and Other Natural Gas-Related Investments, and the spot price of natural gas.

Certain of USNG’s investments could be illiquid which could cause large losses to investors at any time or from time to time.

USNG may not always be able to liquidate its positions in its investments at the desired price. It is difficult to execute a trade at a specific price when there is a relatively small volume of buy and sell orders in a market. A market disruption, such as a foreign government taking political actions that disrupt the market in its currency, its natural gas production or exports, or in another major export, can also make it difficult to liquidate a position. Alternatively, limits imposed by futures exchanges or other regulatory organizations, such as accountability levels, position limits and daily price fluctuation limits, may contribute to a lack of liquidity with respect to some commodity interests.

Unexpected market illiquidity may cause major losses to investors at any time or from time to time. In addition, USNG has not and does not intend at this time to establish a credit facility, which would provide an additional source of liquidity and instead relies only on the Treasuries, cash and/or cash equivalents that it holds. The anticipated large value of the positions in Futures Contracts that USCF will acquire or enter into for USNG increases the risk of illiquidity. The Other Natural Gas-Related Investments that USNG invests in, such as negotiated over-the-counter contracts, may have a greater likelihood of being illiquid since they are contracts between two parties that take into account not only market risk, but also the relative credit, tax, and settlement risks under such contracts. Such contracts also have limited transferability that results from such risks and from the contract’s express limitations.

Because both Futures Contracts and Other Natural Gas-Related Investments may be illiquid, USNG’s Natural Gas Interests may be more difficult to liquidate at favorable prices in periods of illiquid markets and losses may be incurred during the period in which positions are being liquidated.

If the nature of hedgers and speculators in futures markets has shifted such that natural gas purchasers are the predominant hedgers in the market, USNG might have to reinvest at higher futures prices or choose Other Natural Gas-Related Investments.

The changing nature of the hedgers and speculators in the natural gas market influences whether futures prices are above or below the expected future spot price. In order to induce speculators to take the corresponding long side of the same futures contract, natural gas producers must generally be willing to sell futures contracts at prices that are below expected future spot prices. Conversely, if the predominant hedgers in the futures market are the purchasers of the natural gas who purchase futures contracts to hedge against a rise in prices, then speculators will only take the short side of the futures contract if the futures price is greater than the expected future spot price of natural gas. This can have significant implications for USNG when it is time to reinvest the proceeds from a maturing Futures Contract into a new Futures Contract.

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While USNG does not intend to take physical delivery of natural gas under its Futures Contracts, physical delivery under such contracts impacts the value of the contracts.

While it is not the current intention of USNG to take physical delivery of natural gas under its Futures Contracts, futures contracts are not required to be cash-settled and it is possible to take delivery under some of these contracts. Storage costs associated with purchasing natural gas could result in costs and other liabilities that could impact the value of Futures Contracts or Other Natural Gas-Related Investments. Storage costs include the time value of money invested in natural gas as a physical commodity plus the actual costs of storing the natural gas less any benefits from ownership of natural gas that are not obtained by the holder of a futures contract. In general, Futures Contracts have a one-month delay for contract delivery and the back month (the back month is any future delivery month other than the spot month) includes storage costs. To the extent that these storage costs change for natural gas while USNG holds Futures Contracts or Other Natural Gas-Related Investments, the value of the Futures Contracts or Other Natural Gas-Related Investments, and therefore USNG’s NAV, may change as well.

Regulation of the commodity interests and energy markets is extensive and constantly changing; future regulatory developments are impossible to predict but may significantly and adversely affect USNG.

The futures markets are subject to comprehensive statutes, regulations, and margin requirements. In addition, the CFTC and the exchanges are authorized to take extraordinary actions in the event of a market emergency, including, for example, the retroactive implementation of speculative position limits or higher margin requirements, the establishment of daily price limits and the suspension of trading.

The regulation of commodity interest transactions in the United States is a rapidly changing area of law and is subject to ongoing modification by governmental and judicial action. Considerable regulatory attention has been focused on non-traditional investment pools that are publicly distributed in the United States. In addition, various national governments outside the United States have expressed concern regarding the disruptive effects of speculative trading in the energy markets and the need to regulate the derivatives markets in general. The effect of any future regulatory change on USNG is impossible to predict, but it could be substantial and adverse.

For a more detailed discussion of the regulations to be imposed by the CFTC and the SEC and the potential impacts thereof on USNG, please see “Item 1. Business – Regulation” in this annual report on Form 10-K.

Investing in USNG for purposes of hedging may be subject to several risks including the possibility of losing the benefit of favorable market movement.

Participants in the natural gas or in other industries may use USNG as a vehicle to hedge the risk of losses in their natural gas-related transactions. There are several risks in connection with using USNG as a hedging device. While hedging can provide protection against an adverse movement in market prices, it can also preclude a hedger’s opportunity to benefit from a favorable market movement. In a hedging transaction, the hedger may be concerned that the hedged item will increase in price, but must recognize the risk that the price may instead decline and if this happens he will have lost his opportunity to profit from the change in price because the hedging transaction will result in a loss rather than a gain. Thus, the hedger foregoes the opportunity to profit from favorable price movements.

An investment in USNG may provide little or no diversification benefits. Thus, in a declining market, USNG may have no gains to offset losses from other investments, and an investor may suffer losses on an investment in USNG while incurring losses with respect to other asset classes.

Historically, Futures Contracts and Other Natural Gas-Related Investments have generally been non-correlated to the performance of other asset classes such as stocks and bonds. Non-correlation means that there is a low statistically valid relationship between the performance of futures and other commodity interest transactions, on the one hand, and stocks or bonds, on the other hand. However, there can be no assurance that such non-correlation will continue during future periods. If, contrary to historic patterns, USNG’s performance were to move in the same general direction as the financial markets, investors will obtain little or no diversification benefits from an investment in the units. In such a case, USNG may have no gains to offset losses from other investments, and investors may suffer losses on their investment in USNG at the same time they incur losses with respect to other investments.

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Variables such as drought, floods, weather, embargoes, tariffs and other political events may have a larger impact on natural gas prices and natural gas-linked instruments, including Futures Contracts and Other Natural Gas-Related Investments, than on traditional securities. These additional variables may create additional investment risks that subject USNG’s investments to greater volatility than investments in traditional securities.

Non-correlation should not be confused with negative correlation, where the performance of two asset classes would be opposite of each other. There is no historic evidence that the spot price of natural gas and prices of other financial assets, such as stocks and bonds, are negatively correlated. In the absence of negative correlation, USNG cannot be expected to be automatically profitable during unfavorable periods for the stock market, or vice versa.

USNG’s Operating Risks

USNG is not a registered investment company so unitholders do not have the protections of the 1940 Act.

USNG is not an investment company subject to the 1940 Act. Accordingly, investors do not have the protections afforded by that statute which, for example, requires investment companies to have a majority of disinterested directors and regulates the relationship between the investment company and its investment manager.

USCF is leanly staffed and relies heavily on key personnel to manage trading activities.

In managing and directing the day-to-day activities and affairs of USNG, USCF relies heavily on Messrs. Howard Mah and John Hyland. If Messrs. Mah or Hyland were to leave or be unable to carry out their present responsibilities, it may have an adverse effect on the management of USNG. Furthermore, Messrs. Mah and Hyland are currently involved in the management of the Related Public Funds. USCF has also filed registration statements to register units of USSF, UNGD, USGO and UAC, each a series of the United States Commodity Funds Trust I, and HARD, a series of the United States Currency Funds Trust. Mr. Mah is also employed by Ameristock Corporation, a registered investment adviser that until January 11, 2013 managed a public mutual fund. On January 11, 2013, Ameristock Mutual Fund, Inc. was reorganized with and into the Drexel Hamilton Centre American Equity Fund, a series of the Drexel Hamilton Mutual Funds. Drexel Hamilton Mutual Funds and its advisor, Drexel Hamilton Investment Partners, are not affiliated with Ameristock Corporation, the Ameristock Mutual Fund, Inc. or USCF. After the consummation of the reorganization and liquidation, the Ameristock Corporation maintained its non-advisory assets. It is estimated that Mr. Mah will spend approximately 98% of his time on USNG and Related Public Fund matters. Mr. Hyland will spend approximately 100% of his time on USNG and Related Public Fund matters. To the extent that USCF establishes additional funds, even greater demands will be placed on Messrs. Mah and Hyland, as well as the other officers of USCF and its Board.

Accountability levels, position limits, and daily price fluctuation limits set by the exchanges have the potential to cause a tracking error, which could cause the price of units to substantially vary from the price of the Benchmark Futures Contract and prevent investors from being able to effectively use USNG as a way to hedge against natural gas-related losses or as a way to indirectly invest in natural gas.

Designated contract markets, such as the NYMEX and ICE Futures, have established accountability levels and position limits on the maximum net long or net short futures contracts in commodity interests that any person or group of persons under common trading control (other than as a hedge, which an investment by USNG is not) may hold, own or control. In addition to accountability levels and position limits, the NYMEX and ICE Futures also set daily price fluctuation limits on futures contracts. The daily price fluctuation limit establishes the maximum amount that the price of a futures contract may vary either up or down from the previous day’s settlement price. Once the daily price fluctuation limit has been reached in a particular futures contract, no trades may be made at a price beyond that limit.

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In late 2011, the CFTC adopted the Position Limit Rules, which were scheduled to become effective on October 12, 2012. However, on September 28, 2012, the United States District Court for the District of Columbia vacated these regulations on the basis of ambiguities in the provisions of the CEA (as modified by the Dodd-Frank Act) upon which the regulations were based. In its September 28, 2012 decision, the court remanded the Position Limit Rules to the CFTC with instructions to use its expertise and experience to resolve the ambiguities in the statute. On November 15, 2012, the CFTC indicated that it will move forward with an appeal of the District Court’s decision to vacate the Position Limit Rules. At this time, it is not possible to predict how the CFTC’s appeal could affect USNG, but it may be substantial and adverse. Furthermore, until such time as the appeal is resolved or, if applicable revisions to the Position Limit Rules are proposed and adopted, the regulatory architecture in effect prior to the enactment of the Position Limit Rules will govern transactions in commodities and related derivatives. Under that system, the CFTC enforces federal limits on speculation in agricultural products (e.g., corn, wheat and soy) while futures exchanges enforce position limits and accountability levels for agricultural and certain energy products (e.g., oil and natural gas). As a result, USNG may be limited with respect to the size of its investments in any commodities subject to these limits. Finally, subject to certain narrow exceptions, the vacated Position Limit Rules would have required the aggregation, for purposes of the position limits, of all positions in the 28 Referenced Contracts held by a single entity and its affiliates, regardless of whether such position existed on U.S. futures exchanges, non-U.S. futures exchanges, in cleared swaps or in over-the-counter swaps. The CFTC is presently considering new aggregation rules, under a rulemaking proposal that is distinct from the Position Limit Rules. At this time, it is unclear how any modified aggregation rules may affect USNG, but it may be substantial and adverse. By way of example, the aggregation rules in combination with any potential revised Position Limit Rules may negatively impact the ability of USNG to meet its investment objectives through limits that may inhibit USCF’s ability to sell additional Creation Baskets of USNG.

All of these limits may potentially cause a tracking error between the price of the units and the price of the Benchmark Futures Contract. This may in turn prevent investors from being able to effectively use USNG as a way to hedge against natural gas-related losses or as a way to indirectly invest in natural gas.

USNG has not limited the size of its offering and is committed to utilizing substantially all of its proceeds to purchase Futures Contracts and Other Natural Gas-Related Investments. If USNG encounters accountability levels, position limits, or price fluctuation limits for Futures Contracts on the NYMEX or ICE Futures, it may then, if permitted under applicable regulatory requirements, purchase Futures Contracts and Other Natural Gas-Related Investments on other exchanges that trade listed natural gas futures. In addition, if USNG exceeds accountability levels on either the NYMEX or ICE Futures and is required by such exchanges to reduce its holdings, such reduction could potentially cause a tracking error between the price of the units and the price of the Benchmark Futures Contract.

To the extent that USCF uses spreads and straddles as part of its trading strategy, there is the risk that the per unit NAV may not closely track the changes in the Benchmark Futures Contract.

If USCF were to utilize a spread or straddle position and the spread performed differently than expected, the results could impact USNG’s tracking error. This could affect USNG’s investment objective of having its per unit NAV closely track the changes in the Benchmark Futures Contract. Additionally, a loss on a spread position would negatively impact USNG’s absolute return. For a more detailed discussion regarding spreads and straddles, please see “Item 1. Business – Spreads and Straddles” in this annual report on Form 10-K.

USNG and USCF may have conflicts of interest, which may permit them to favor their own interests to the detriment of unitholders.

USNG and USCF may have inherent conflicts to the extent USCF attempts to maintain USNG’s asset size in order to preserve its fee income and this may not always be consistent with USNG’s objective of having the value of its units’ per unit NAV track the changes in the Benchmark Futures Contract. USCF’s officers, directors and employees do not devote their time exclusively to USNG. These persons are directors, officers or employees of other entities that may compete with USNG for their services. They could have a conflict between their responsibilities to USNG and to those other entities.

In addition, USCF’s principals, officers, directors or employees may trade futures and related contracts for their own account. A conflict of interest may exist if their trades are in the same markets and at the same time as USNG trades using the clearing broker to be used by USNG. A potential conflict also may occur if USCF’s principals, officers, directors or employees trade their accounts more aggressively or take positions in their accounts which are opposite, or ahead of, the positions taken by USNG.

USCF has sole current authority to manage the investments and operations of USNG, and this may allow it to act in a way that furthers its own interests which may create a conflict with the best interests of investors. Limited partners have limited voting control, which will limit the ability to influence matters such as amendment of the LP Agreement, change in USNG’s basic investment policy, dissolution of this fund, or the sale or distribution of USNG’s assets.

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USCF serves as the general partner to each of USNG, USOF, US12OF, UGA, USDHO, USSO, US12NG and USBO and the sponsor for USCI, CPER, USAG and USMI, and will serve as the sponsor for USSF, UNGD, USGO, UAC and HARD, if such funds offer their securities to the public or begin operations. USCF may have a conflict to the extent that its trading decisions for USNG may be influenced by the effect they would have on the other funds it manages. These trading decisions may be influenced since USCF also serves as the general partner or sponsor for all of the funds and is required to meet all of the funds’ investment objectives as well as USNG’s. If USCF believes that a trading decision it made on behalf of USNG might (i) impede its other funds from reaching their investment objectives, or (ii) improve the likelihood of meeting its other funds’ objectives, then USCF may choose to change its trading decision for USNG, which could either impede or improve the opportunity for USNG to meet its investment objective. In addition, USCF is required to indemnify the officers and directors of its other funds if the need for indemnification arises. This potential indemnification will cause USCF’s assets to decrease. If USCF’s other sources of income are not sufficient to compensate for the indemnification, then USCF may terminate and investors could lose their investment.

Unitholders may only vote on the removal of USCF and limited partners have only limited voting rights. Unitholders and limited partners will not participate in the management of USNG and do not control USCF so they will not have influence over basic matters that affect USNG. In addition, USNG could terminate at any time and cause the liquidation and potential loss of an investor’s investment and could upset the overall maturity and timing of an investor’s investment portfolio.

Limited partners will have limited voting rights with respect to USNG’s affairs. Unitholders must apply to become limited partners, and unitholders that have not applied to become limited partners have no voting rights, other than to remove USCF as the general partner of USNG. Even then, unitholders may remove USCF only if 66 2/3% of the unitholders elect to do so. Unitholders and limited partners will not be permitted to participate in the management or control of USNG or the conduct of its business. Unitholders and limited partners must therefore rely upon the duties and judgment of USCF to manage USNG’s affairs.

USNG may terminate at any time, regardless of whether USNG has incurred losses, subject to the terms of the LP Agreement. In particular, unforeseen circumstances, including the death, adjudication of incompetence, bankruptcy, dissolution, or removal of USCF as the general partner of USNG could cause USNG to terminate unless a majority interest of the limited partners within 90 days of the event elects to continue the partnership and appoints a successor general partner, or the affirmative vote of a majority in interest of the limited partners subject to certain conditions. However, no level of losses will require USCF to terminate USNG. USNG’s termination would cause the liquidation and potential loss of an investor’s investment. Termination could also negatively affect the overall maturity and timing of an investor’s investment portfolio.

USCF may manage a large amount of assets and this could affect USNG’s ability to trade profitably.

Increases in assets under management may affect trading decisions. In general, USCF does not intend to limit the amount of assets of USNG that it may manage. The more assets USCF manages, the more difficult it may be for it to trade profitably because of the difficulty of trading larger positions without adversely affecting prices and performance and of managing risk associated with larger positions.

Limited partners may have limited liability in certain circumstances, including potentially having liability for the return of wrongful distributions.

Under Delaware law, a limited partner might be held liable for USNG’s obligations as if it were a general partner if the limited partner participates in the control of the partnership’s business and the persons who transact business with the partnership think the limited partner is the general partner.

A limited partner will not be liable for assessments in addition to its initial capital investment in any of USNG’s capital securities representing units. However, a limited partner may be required to repay to USNG any amounts wrongfully returned or distributed to it under some circumstances. Under Delaware law, USNG may not make a distribution to limited partners if the distribution causes USNG’s liabilities (other than liabilities to partners on account of their partnership interests and nonrecourse liabilities) to exceed the fair value of USNG’s assets. Delaware law provides that a limited partner who receives such a distribution and knew at the time of the distribution that the distribution violated the law will be liable to the limited partnership for the amount of the distribution for three years from the date of the distribution.

With adequate notice, a limited partner may be required to withdraw from the partnership for any reason.

If USCF gives at least fifteen (15) days’ written notice to a limited partner, then USCF may for any reason, in its sole discretion, require any such limited partner to withdraw entirely from the partnership or to withdraw a portion of its partner capital account. USCF may require withdrawal even in situations where the limited partner has complied completely with the provisions of the LP Agreement.

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USNG does not expect to make cash distributions.

USNG has not previously made any cash distributions and intends to re-invest any realized gains in additional Natural Gas Interests rather than distributing cash to limited partners. Therefore, unlike mutual funds, commodity pools or other investment pools that actively manage their investments in an attempt to realize income and gains from their investing activities and distribute such income and gains to their investors, USNG generally does not expect to distribute cash to limited partners. An investor should not invest in USNG if it will need cash distributions from USNG to pay taxes on its share of income and gains of USNG, if any, or for any other reason. Although USNG does not intend to make cash distributions, the income earned from its investments held directly or posted as margin may reach levels that merit distribution, e.g., at levels where such income is not necessary to support its underlying investments in Natural Gas Interests and investors adversely react to being taxed on such income without receiving distributions that could be used to pay such tax. If this income becomes significant then cash distributions may be made.

There is a risk that USNG will not earn trading gains sufficient to compensate for the fees and expenses that it must pay and as such USNG may not earn any profit.

USNG pays brokerage charges of approximately 0.33% of average total net assets, based on FCM fees of $3.50 per buy or sell, management fees of 0.60% of NAV on the first $1,000,000,000 of its average net assets and 0.50% of NAV after the first $1,000,000,000 of its average net assets, and over-the-counter spreads and extraordinary expenses (e.g., subsequent offering expenses, other expenses not in the ordinary course of business, including the indemnification of any person against liabilities and obligations to the extent permitted by law and required under the LP Agreement and under agreements entered into by USCF on USNG’s behalf and the bringing and defending of actions at law or in equity and otherwise engaging in the conduct of litigation and the incurring of legal expenses and the settlement of claims and litigation) that cannot be quantified.

These fees and expenses must be paid in all cases regardless of whether USNG’s activities are profitable. Accordingly, USNG must earn trading gains sufficient to compensate for these fees and expenses before it can earn any profit.

If offerings of the units do not raise sufficient funds to pay USNG’s future expenses and no other source of funding of expenses is found, USNG may be forced to terminate and investors may lose all or part of their investment.

Prior to the offering of units that commenced on April 18, 2007, all of USNG’s expenses were funded by USCF and its affiliates. These payments by USCF and its affiliates were designed to allow USNG the ability to commence the public offering of its units. USNG now directly pays certain of these fees and expenses. USCF will continue to pay other fees and expenses, as set forth in the LP Agreement. If USCF and USNG are unable to raise sufficient funds to cover their expenses or locate any other source of funding, USNG may be forced to terminate and investors may lose all or part of their investment.

USNG may incur higher fees and expenses upon renewing existing or entering into new contractual relationships.

The clearing arrangements between the clearing brokers and USNG generally are terminable by the clearing brokers once the clearing broker has given USNG notice. Upon termination, USCF may be required to renegotiate or make other arrangements for obtaining similar services if USNG intends to continue trading in Futures Contracts or Other Natural Gas-Related Investments at its present level of capacity. The services of any clearing broker may not be available, or even if available, these services may not be available on the terms as favorable as those of the expired or terminated clearing arrangements.

USNG may miss certain trading opportunities because it will not receive the benefit of the expertise of independent trading advisors.

USCF does not employ trading advisors for USNG; however, it reserves the right to employ them in the future. The only advisor to USNG is USCF. A lack of independent trading advisors may be disadvantageous to USNG because it will not receive the benefit of a trading advisor’s expertise.

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An unanticipated number of redemption requests during a short period of time could have an adverse effect on the NAV of USNG.

If a substantial number of requests for redemption of Redemption Baskets are received by USNG during a relatively short period of time, USNG may not be able to satisfy the requests from USNG’s assets not committed to trading. As a consequence, it could be necessary to liquidate positions in USNG’s trading positions before the time that the trading strategies would otherwise dictate liquidation.

The financial markets are currently in a slow period of recovery and the financial markets are still relatively fragile.

Since 2008, the financial markets have experienced very difficult conditions and volatility as well as significant adverse trends. The conditions in these markets have resulted in a decrease in availability of corporate credit and liquidity and have led indirectly to the insolvency, closure or acquisition of a number of major financial institutions and have contributed to further consolidation within the financial services industry. In addition, the Administration and Congress have periodically been reaching impasses in passing a fiscal budget which could create long-term concerns regarding the credit of the United States and interest earned, as well as the United States Government’s ability to pay its obligations to holders of Treasuries. If low interest rates on Treasuries continue or if USNG is not able to redeem its investments in Treasuries prior to maturity and the U.S. Government cannot pay its obligations, USNG would be negatively impacted. In addition, USNG might also be negatively impacted by its use of money market mutual funds to the extent those funds might themselves be using Treasuries. Although the financial markets saw signs of recovery beginning in late 2010 and 2011, economic growth in 2012 was slow and the financial markets are still fragile. A poor financial recovery could adversely affect the financial condition and results of operations of USNG’s service providers and Authorized Purchasers which would impact the ability of USCF to achieve USNG’s investment objective.

The failure or bankruptcy of a clearing broker or USNG’s Custodian could result in a substantial loss of USNG’s assets and could impair USNG in its ability to execute trades.

Under CFTC regulations, a clearing broker maintains customers’ assets in a bulk segregated account. If a clearing broker fails to do so, or even if the customers’ funds are segregated by the clearing broker but the clearing broker is unable to satisfy a substantial deficit in a customer account, the clearing broker’s other customers may be subject to risk of a substantial loss of their funds in the event of that clearing broker’s bankruptcy. In that event, the clearing broker’s customers, such as USNG, are entitled to recover, even in respect of property specifically traceable to them, only a proportional share of all property available for distribution to all of that clearing broker’s customers. The bankruptcy of a clearing broker could result in the complete loss of USNG’s assets posted with the clearing broker; though the majority of USNG’s assets are held in Treasuries, cash and/or cash equivalents with the Custodian and would not be impacted by the bankruptcy of a clearing broker. USNG also may be subject to the risk of the failure of, or delay in performance by, any exchanges and markets and their clearing organizations, if any, on which commodity interest contracts are traded.

In addition, to the extent USNG’s clearing broker is required to post USNG’s assets as margin to a clearinghouse, the margin will be maintained in an omnibus account containing the margin of all the clearing broker’s customers. If USNG’s clearing broker defaults to a clearinghouse because of a default by one of the clearing broker’s other customers or otherwise, then the clearinghouse can look to all of the margin in the omnibus account, including margin posted by USNG and any other non-defaulting customers of the clearing broker to satisfy the obligations of the clearing broker.

From time to time, the clearing brokers may be subject to legal or regulatory proceedings in the ordinary course of their business. A clearing broker’s involvement in costly or time-consuming legal proceedings may divert financial resources or personnel away from the clearing broker’s trading operations, which could impair the clearing broker’s ability to successfully execute and clear USNG’s trades.

In addition, the majority of USNG’s assets are held in Treasuries, cash and/or cash equivalents with the Custodian. The insolvency of the Custodian could result in a complete loss of USNG’s assets held by that Custodian, which, at any given time, would likely comprise a substantial portion of USNG’s total assets.

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Third parties may infringe upon or otherwise violate intellectual property rights or assert that USCF has infringed or otherwise violated their intellectual property rights, which may result in significant costs and diverted attention.

Third parties may utilize USNG’s intellectual property or technology, including the use of its business methods, trademarks and trading program software, without permission. USCF has a patent for USNG’s business method and has registered its trademarks. USNG does not currently have any proprietary software. However, if it obtains proprietary software in the future, then any unauthorized use of USNG’s proprietary software and other technology could also adversely affect its competitive advantage. USNG may not have adequate resources to implement procedures for monitoring unauthorized uses of its patents, trademarks, proprietary software and other technology. Also, third parties may independently develop business methods, trademarks or proprietary software and other technology similar to that of USCF or claim that USCF has violated their intellectual property rights, including their copyrights, trademark rights, trade names, trade secrets and patent rights. As a result, USCF may have to litigate in the future to protect its trade secrets, determine the validity and scope of other parties’ proprietary rights, defend itself against claims that it has infringed or otherwise violated other parties’ rights, or defend itself against claims that its rights are invalid. Any litigation of this type, even if USCF is successful and regardless of the merits, may result in significant costs, divert its resources from USNG, or require it to change its proprietary software and other technology or enter into royalty or licensing agreements.

The success of USNG depends on the ability of USCF to accurately implement trading systems, and any failure to do so could subject USNG to losses on such transactions.

USCF uses mathematical formulas built into a generally available spreadsheet program to decide whether it should buy or sell Natural Gas Interests each day. Specifically, USCF uses the spreadsheet to make mathematical calculations and to monitor positions in Natural Gas Interests and Treasuries and correlations to the Benchmark Futures Contract. USCF must accurately process the spreadsheets’ outputs and execute the transactions called for by the formulas. In addition, USNG relies on USCF to properly operate and maintain its computer and communications systems. Extraordinary transaction volume, hardware or software failure, power or telecommunications failure, a natural disaster or other catastrophe could cause the computer systems to operate at an unacceptably slow speed or even fail. Any significant degradation or failure of the systems that USCF uses to gather and analyze information, enter orders, process data, monitor risk levels and otherwise engage in trading activities may result in substantial losses on transactions, liability to other parties, lost profit opportunities, damages to USCF’s and USNG’s reputations, increased operational expenses and diversion of technical resources. Any failure, inaccuracy or delay in implementing any of the formulas or systems, including implementing upgrades and compatibility with the computer systems of third parties, and executing USNG’s transactions could impair its ability to achieve USNG’s investment objective. It could also result in decisions to undertake transactions based on inaccurate or incomplete information. This could cause substantial losses on transactions.

The occurrence of a terrorist attack, or the outbreak, continuation or expansion of war or other hostilities could disrupt USNG’s trading activity and materially affect USNG’s profitability.

The operations of USNG, the exchanges, brokers and counterparties with which USNG does business, and the markets in which USNG does business could be severely disrupted in the event of a major terrorist attack or the outbreak, continuation or expansion of war or other hostilities. Global anti-terrorism initiatives, political unrest in the Middle East and Southeast Asia, as well as political hostility towards the United States, continue to fuel this concern.

Risk of Leverage and Volatility

If USCF permits USNG to become leveraged, investors could lose all or substantially all of their investment if USNG’s trading positions suddenly turn unprofitable.

Commodity pools’ trading positions in futures contracts or other commodity interests are typically required to be secured by the deposit of margin funds that represent only a small percentage of a futures contract’s (or other commodity interests’) entire market value. This feature permits commodity pools to “leverage” their assets by purchasing or selling futures contracts (or other commodity interests) with an aggregate value in excess of the commodity pool’s assets. While this leverage can increase the pool’s profits, relatively small adverse movements in the price of the pool’s futures contracts can cause significant losses to the pool. While USCF has not and does not currently intend to leverage USNG’s assets, it is not prohibited from doing so under the LP Agreement or otherwise.

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The price of natural gas is volatile which could cause large fluctuations in the price of units.

Movements in the price of natural gas may be the result of factors outside of USCF’s control and may not be anticipated by USCF. Among the factors that can cause volatility in the price of natural gas are:

Over-the-Counter Contract Risk

Currently, over-the-counter transactions are subject to changing regulation.

A portion of USNG’s assets may be used to trade over-the-counter contracts, such as forward contracts or swap or spot contracts. Currently, over-the-counter contracts are typically contracts traded on a principal-to-principal, non-cleared basis through dealer markets that are dominated by major money center and investment banks and other institutions and that prior to the passage of the Dodd-Frank Act had been essentially unregulated by the CFTC. The markets for over-the-counter contracts have relied upon the integrity of market participants in lieu of the additional regulation imposed by the CFTC on participants in the futures markets. To date, the forward markets have been largely unregulated, forward contracts have been executed bi-laterally and, in general, forward contracts have not been cleared or guaranteed by a third party. On November 16, 2012, the Secretary of the Treasury issued a final determination that exempts both foreign exchange swaps and foreign exchange forwards from the definition of “swap” and, by extension, additional regulatory requirements (such as clearing and margin). The final determination does not extend to other foreign derivatives, such as foreign exchange options, certain currency swaps and non-deliverable forwards. While the Dodd-Frank Act and certain regulations adopted thereunder are intended to provide additional protections to participants in the over-the-counter market, the current regulation of the over-the-counter contracts could expose USNG in certain circumstances to significant losses in the event of trading abuses or financial failure by participants. On November 28, 2012, the CFTC issued its final clearing determination requiring that certain credit default swaps and interest rate swaps be cleared by registered DCOs. This is the CFTC’s first clearing determination under the Dodd-Frank Act and became effective on February 11, 2013. Determination on other types of swaps are expected in the future, and, when finalized, could require USNG to centrally clear certain over-the-counter instruments presently entered into and settled on a bi-lateral basis. See “Item 1. Business – Regulation” for a discussion of how the over-the-counter market will be subject to much more extensive CFTC oversight and regulation after the implementation of the Dodd-Frank Act.

USNG will be subject to credit risk with respect to counterparties to over-the-counter contracts entered into by USNG or held by special purpose or structured vehicles.

USNG faces the risk of non-performance by the counterparties to the over-the-counter contracts. Unlike in futures contracts, the counterparty to these contracts is generally a single bank or other financial institution, rather than a clearing organization backed by a group of financial institutions. As a result, there will be greater counterparty credit risk in these transactions. A counterparty may not be able to meet its obligations to USNG, in which case USNG could suffer significant losses on these contracts.

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If a counterparty becomes bankrupt or otherwise fails to perform its obligations due to financial difficulties, USNG may experience significant delays in obtaining any recovery in a bankruptcy or other reorganization proceeding. USNG may obtain only limited recovery or may obtain no recovery in such circumstances.

USNG may be subject to liquidity risk with respect to its over-the-counter contracts.

Over-the-counter contracts are less marketable because they are not traded on an exchange, do not have uniform terms and conditions, and are entered into based upon the creditworthiness of the parties and the availability of credit support, such as collateral, and in general, they are not transferable without the consent of the counterparty. These conditions make such contracts less liquid than standardized futures contracts traded on a commodities exchange and could adversely impact USNG’s ability to realize the full value of such contracts. In addition, even if collateral is used to reduce counterparty credit risk, sudden changes in the value of over-the-counter transactions may leave a party open to financial risk due to a counterparty default since the collateral held may not cover a party’s exposure on the transaction in such situations.

In general, valuing over-the-counter derivatives is less certain than valuing actively traded financial instruments such as exchange traded futures contracts and securities or cleared swaps because the price and terms on which such over-the-counter derivatives are entered into or can be terminated are individually negotiated, and those prices and terms may not reflect the best price or terms available from other sources. In addition, while market makers and dealers generally quote indicative prices or terms for entering into or terminating over-the-counter contracts, they typically are not contractually obligated to do so, particularly if they are not a party to the transaction. As a result, it may be difficult to obtain an independent value for an outstanding over-the-counter derivatives transaction.

The Dodd-Frank Act requires the CFTC and SEC to establish “both initial and variation margin requirements on all swaps that are not cleared by a registered clearing organization” (i.e., uncleared swaps). In addition, the Dodd-Frank Act provides parties who post initial margin to a swap dealer or major swap participant with a statutory right to insist that such margin be held in a segregated account with an independent custodian. At this time, the CFTC has proposed a rule addressing this statutory right of certain market participants but has not yet implemented any final rules. On November 16, 2012, the Secretary of the Treasury issued a final determination that exempts both foreign exchange swaps and foreign exchange forwards from the definition of “swap” and, by extension, additional regulatory requirements (such as clearing and margin).

Risk of Trading in International Markets

Trading in international markets could expose USNG to credit and regulatory risk.

USNG invests primarily in Futures Contracts, a significant portion of which are traded on United States exchanges, including the NYMEX. However, a portion of USNG’s trades may take place on markets and exchanges outside the United States. Some non-U.S. markets present risks because they are not subject to the same degree of regulation as their U.S. counterparts. The CFTC, NFA and the domestic exchanges have little, if any, regulatory authority over the activities of any foreign boards of trade or exchanges, including the execution, delivery and clearing of transactions, and have little, if any, power to compel enforcement of the rules of a foreign board of trade or exchange or of any applicable non-U.S. laws. Similarly, the rights of market participants, such as USNG, in the event of the insolvency or bankruptcy of a non-U.S. market or broker are also likely to be more limited than in the case of U.S. markets or brokers. As a result, in these markets, USNG has less legal and regulatory protection than it does when it trades domestically.

In some of these non-U.S. markets, the performance on a contract is the responsibility of the counterparty and is not backed by an exchange or clearing corporation and therefore exposes USNG to credit risk. Trading in non-U.S. markets also leaves USNG susceptible to swings in the value of the local currency against the U.S. dollar. Additionally, trading on non-U.S. exchanges is subject to the risks presented by exchange controls, expropriation, increased tax burdens and exposure to local economic declines and political instability. An adverse development with respect to any of these variables could reduce the profit or increase the loss earned on trades in the affected international markets.

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International trading activities subject USNG to foreign exchange risk.

The price of any non-U.S. commodity interest and, therefore, the potential profit and loss on such investment, may be affected by any variance in the foreign exchange rate between the time the order is placed and the time it is liquidated, offset or exercised. As a result, changes in the value of the local currency relative to the U.S. dollar may cause losses to USNG even if the contract traded is profitable.

USNG’s international trading could expose it to losses resulting from non-U.S. exchanges that are less developed or less reliable than United States exchanges.

Some non-U.S. exchanges may be in a more developmental stage so that prior price histories may not be indicative of current price dynamics. In addition, USNG may not have the same access to certain positions on foreign trading exchanges as do local traders, and the historical market data on which USCF bases its strategies may not be as reliable or accessible as it is for U.S. exchanges.

Tax Risk

An investor’s tax liability may exceed the amount of distributions, if any, on its units.

Cash or property will be distributed at the sole discretion of USCF. USCF has not and does not currently intend to make cash or other distributions with respect to units. Investors will be required to pay U.S. federal income tax and, in some cases, state, local, or foreign income tax, on their allocable share of USNG’s taxable income, without regard to whether they receive distributions or the amount of any distributions. Therefore, the tax liability of an investor with respect to its units may exceed the amount of cash or value of property (if any) distributed.

An investor’s allocable share of taxable income or loss may differ from its economic income or loss on its units.

Due to the application of the assumptions and conventions applied by USNG in making allocations for tax purposes and other factors, an investor’s allocable share of USNG’s income, gain, deduction or loss may be different than its economic profit or loss from its units for a taxable year. This difference could be temporary or permanent and, if permanent, could result in it being taxed on amounts in excess of its economic income.

Items of income, gain, deduction, loss and credit with respect to units could be reallocated if the IRS does not accept the assumptions and conventions applied by USNG in allocating those items, with potential adverse consequences for an investor.

The U.S. tax rules pertaining to partnerships are complex and their application to large, publicly traded partnerships such as USNG is in many respects uncertain. USNG applies certain assumptions and conventions in an attempt to comply with the intent of the applicable rules and to report taxable income, gains, deductions, losses and credits in a manner that properly reflects unitholders’ economic gains and losses. These assumptions and conventions may not fully comply with all aspects of the Internal Revenue Code (the “Code”) and applicable Treasury Regulations, however, and it is possible that the U.S. Internal Revenue Service will successfully challenge USNG’s allocation methods and require USNG to reallocate items of income, gain, deduction, loss or credit in a manner that adversely affects investors. If this occurs, investors may be required to file an amended tax return and to pay additional taxes plus deficiency interest.

USNG could be treated as a corporation for federal income tax purposes, which may substantially reduce the value of the units.

USNG has received an opinion of counsel that, under current U.S. federal income tax laws, USNG will be treated as a partnership that is not taxable as a corporation for U.S. federal income tax purposes, provided that (i) at least 90 percent of USNG’s annual gross income consists of “qualifying income” as defined in the Code, (ii) USNG is organized and operated in accordance with its governing agreements and applicable law and (iii) USNG does not elect to be taxed as a corporation for federal income tax purposes. Although USCF anticipates that USNG has satisfied and will continue to satisfy the “qualifying income” requirement for all of its taxable years, that result cannot be assured. USNG has not requested and will not request any ruling from the IRS with respect to its classification as a partnership not taxable as a corporation for federal income tax purposes. If the IRS were to successfully assert that USNG is taxable as a corporation for federal income tax purposes in any taxable year, rather than passing through its income, gains, losses and deductions proportionately to unitholders, USNG would be subject to tax on its net income for the year at corporate tax rates. In addition, although USCF does not currently intend to make distributions with respect to units, any distributions would be taxable to unitholders as dividend income. Taxation of USNG as a corporation could materially reduce the after-tax return on an investment in units and could substantially reduce the value of the units.

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USNG is organized and operated as a limited partnership in accordance with the provisions of the LP Agreement and applicable state law, and therefore, USNG has a more complex tax treatment than traditional mutual funds.

USNG is organized and operated as a limited partnership in accordance with the provisions of the LP Agreement and applicable state law. No U.S. federal income tax is paid by USNG on its income. Instead, USNG will furnish unitholders each year with tax information on IRS Schedule K-1 (Form 1065) and each U.S. unitholder is required to report on its U.S. federal income tax return its allocable share of the income, gain, loss and deduction of USNG. This must be reported without regard to the amount (if any) of cash or property the unitholder receives as a distribution from USNG during the taxable year. A unitholder, therefore, may be allocated income or gain by USNG but receive no cash distribution with which to pay the tax liability resulting from the allocation, or may receive a distribution that is insufficient to pay such liability.

In addition to federal income taxes, unitholders may be subject to other taxes, such as state and local income taxes, unincorporated business taxes, business franchise taxes and estate, inheritance or intangible taxes that may be imposed by the various jurisdictions in which USNG does business or owns property or where the unitholders reside. Although an analysis of those various taxes is not presented here, each prospective unitholder should consider their potential impact on its investment in USNG. It is each unitholder’s responsibility to file the appropriate U.S. federal, state, local and foreign tax returns.

Item 1B.  Unresolved Staff Comments.

Not applicable.

Item 2.    Properties.

Not applicable.

Item 3.    Legal Proceedings.

Although USNG may, from time to time, be involved in litigation arising out of its operations in the normal course of business or otherwise, USNG is currently not a party to any pending material legal proceedings.

Item 4.    Mine Safety Disclosures.

Not applicable.

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Part II

Item 5.    Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities.

Price Range of Units

USNG’s units have traded on the NYSE Arca under the symbol “UNG” since November 25, 2008. Prior to trading on the NYSE Arca, USNG’s units traded on the AMEX under the symbol “UNG” since its initial public offering on April 18, 2007. The following table sets forth the range of reported high and low sales prices of the units as reported on the AMEX and NYSE Arca, as applicable, for the periods indicated below.

* Adjusted to give effect to the reverse unit split of 2-for-1 executed on March 8, 2011 and the reverse unit split of 4-for-1 executed on February 21, 2012.

** Adjusted to give effect to the reverse unit split of 4-for-1 executed on February 21, 2012.

As of December 31, 2012, USNG had approximately 139,657 holders of units.

Dividends

USNG has not made and does not currently intend to make cash distributions to its unitholders.

Issuer Purchases of Equity Securities

USNG does not purchase units directly from its unitholders; however, in connection with its redemption of baskets held by Authorized Purchasers, USNG redeemed 1,343 baskets (comprising 113,157,981 units) during the year ended December 31, 2012.

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Item 6.    Selected Financial Data.

Financial Highlights (for the years ended December 31, 2012, 2011, 2010, 2009 and 2008)

(Dollar amounts in 000’s except for per unit information)

* Adjusted to give effect to the reverse unit split of 4-for-1 executed on February 21, 2012.

** Adjusted to give effect to the reverse unit split of 2-for-1 executed on March 8, 2011 and the reverse unit split of 4-for-1 executed on February 21, 2012.

Item 7.    Management’s Discussion and Analysis of Financial Condition and Results of Operations.

The following discussion should be read in conjunction with the financial statements and the notes thereto of USNG included elsewhere in this annual report on Form 10-K.

Forward-Looking Information

This annual report on Form 10-K, including this “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” contains forward-looking statements regarding the plans and objectives of management for future operations. This information may involve known and unknown risks, uncertainties and other factors that may cause USNG’s actual results, performance or achievements to be materially different from future results, performance or achievements expressed or implied by any forward-looking statements. Forward-looking statements, which involve assumptions and describe USNG’s future plans, strategies and expectations, are generally identifiable by use of the words “may,” “will,” “should,” “expect,” “anticipate,” “estimate,” “believe,” “intend” or “project,” the negative of these words, other variations on these words or comparable terminology. These forward-looking statements are based on assumptions that may be incorrect, and USNG cannot assure investors that the projections included in these forward-looking statements will come to pass. USNG’s actual results could differ materially from those expressed or implied by the forward-looking statements as a result of various factors.

USNG has based the forward-looking statements included in this annual report on Form 10-K on information available to it on the date of this annual report on Form 10-K, and USNG assumes no obligation to update any such forward-looking statements. Although USNG undertakes no obligation to revise or update any forward-looking statements, whether as a result of new information, future events or otherwise, investors are advised to consult any additional disclosures that USNG may make directly to them or through reports that USNG in the future files with the SEC, including annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K.

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Introduction

USNG, a Delaware limited partnership, is a commodity pool that issues units that may be purchased and sold on the NYSE Arca. The investment objective of USNG is for the daily changes in percentage terms of its units’ NAV to reflect the daily changes in percentage terms of the spot price of natural gas delivered at the Henry Hub, Louisiana, as measured by the daily changes in the price of the futures contract for natural gas traded on the NYMEX that is the near month contract to expire, except when the near month contract is within two weeks of expiration, in which case it will be measured by the futures contract that is the next month contract to expire (the “Benchmark Futures Contract”), less USNG’s expenses. “Near month contract” means the next contract traded on the NYMEX due to expire. “Next month contract” means the first contract traded on the NYMEX due to expire after the near month contract. It is not the intent of USNG to be operated in a fashion such that the per unit NAV will equal, in dollar terms, the spot price of natural gas or any particular futures contract based on natural gas. It is not the intent of USNG to be operated in a fashion such that its NAV will reflect the percentage change of the price of any particular futures contract as measured over a time period greater than one day. USCF believes that it is not practical to manage the portfolio to achieve such an investment goal when investing in Futures Contracts and Other Natural Gas-Related Investments.

USNG seeks to achieve its investment objective by investing in a combination of natural gas Futures Contracts and Other Natural Gas-Related Investments such that daily changes in its per unit NAV, measured in percentage terms, will closely track the daily changes in the price of the Benchmark Futures Contract, also measured in percentage terms. USCF believes the daily changes in the price of the Benchmark Futures Contract have historically exhibited a close correlation with the daily changes in the spot price of natural gas.

On any valuation day, the Benchmark Futures Contract is the near month futures contract for natural gas traded on the NYMEX unless the near month contract is within two weeks of expiration in which case the Benchmark Futures Contract becomes, over a 4-day period, the next month contract for natural gas traded on the NYMEX.

USNG invests in Futures Contracts for crude oil, heating oil, gasoline and other petroleum-based fuels that are traded on the NYMEX, ICE Futures or other U.S. and foreign exchanges and Other Natural Gas-Related Investments. Due, in part, to the increased size of USNG over the last several quarters and its obligation to comply with regulatory limits, it is likely that it will invest in increased numbers of Other Natural Gas-Related Investments in order to fulfill its investment objective.

The regulation of commodity interest trading in the United States and other countries is an evolving area of the law, as exemplified by the various discussions of the Dodd-Frank Act. The various statements made in this summary are subject to modification by legislative action and changes in the rules and regulations of the CFTC, the NFA, the futures exchanges, clearing organizations and other regulatory bodies. Pending final resolution of all applicable regulatory requirements, some specific examples of how the new Dodd-Frank Act provisions and rules adopted thereunder could impact USNG are discussed in “Item 1. Business” and “Item 1A. Risk Factors” in this annual report on Form 10-K.

Price Movements

Natural gas futures prices were volatile during the year ended December 31, 2012. The price of the Benchmark Futures Contract started the year at $2.989 per million British thermal units (“MMBtu”). The low of the period was on April 12, 2012, when the price dropped to $1.983 per MMBtu. The high of the period was on November 23, 2012, when the price reached $4.034 per MMBtu. The period ended with the Benchmark Futures Contract at $3.351 per MMBtu, an increase of approximately 12.11% over the year. USNG’s per unit NAV initially rose during the year ended December 31, 2012, taking into account the reverse split, from a starting level of $25.88* to a high on January 4, 2012 of $26.82*. USNG’s per unit NAV reached its low for the year on April 19, 2012 at $14.29. The per unit NAV on December 31, 2012 was $18.87, a decrease of approximately 27.09% over the year. The Benchmark Futures Contract prices listed above began with the February 2012 contracts and ended with the February 2013 contracts. The increase of approximately 12.11% on the Benchmark Futures Contract listed above is a hypothetical return only and could not actually be achieved by an investor holding Futures Contracts. An investment in natural gas Futures Contracts would need to be rolled forward during the time period described in order to simulate such a result. Furthermore, the change in the nominal price of these differing natural gas Futures Contracts, measured from the start of the year to the end of the year, does not represent the actual benchmark results that USNG seeks to track, which are more fully described below, in the section titled “Tracking USNG’s Benchmark.”

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During the year ended December 31, 2012, the natural gas futures market was primarily in a state of contango, meaning that the price of the near month natural gas Futures Contract was lower than the price of the next month natural gas Futures Contract, or contracts further away from expiration. A contango market is one in which the price of the near month natural gas Futures Contract is less than the price of the next month natural gas Futures Contract, or contracts further away from expiration. For a discussion of the impact of backwardation and contango on total returns, see “Term Structure of Natural Gas Futures Prices and the Impact on Total Returns” below.

* Adjusted to give effect to the reverse unit split of 4-for-1 executed on February 21, 2012.

Valuation of Futures Contracts and the Computation of the Per Unit NAV

The per unit NAV of USNG’s units is calculated once each NYSE Arca trading day. The per unit NAV for a particular trading day is released after 4:00 p.m. New York time. Trading during the core trading session on the NYSE Arca typically closes at 4:00 p.m. New York time. The Administrator uses the NYMEX closing price (determined at the earlier of the close of the NYMEX or 2:30 p.m. New York time) for the contracts held on the NYMEX, but calculates or determines the value of all other USNG investments, including cleared swaps or other futures contracts, as of the earlier of the close of the NYSE Arca or 4:00 p.m. New York time.

Results of Operations and the Natural Gas Market

Results of Operations. On April 18, 2007, USNG listed its units on the AMEX under the ticker symbol “UNG.” On that day, USNG established its initial offering price at $50.00 per unit and issued 200,000 units to the initial Authorized Purchaser, Merrill Lynch Professional Clearing Corp., in exchange for $10,000,000 in cash. As a result of the acquisition of the AMEX by NYSE Euronext, USNG’s units no longer trade on the AMEX and commenced trading on the NYSE Arca on November 25, 2008.

Since its initial offering of 30,000,000 units, USNG has registered four subsequent offerings of its units: 50,000,000 units which were registered with the SEC on November 21, 2007, 100,000,000 units which were registered with the SEC on August 28, 2008, 300,000,000 units which were registered with the SEC on May 6, 2009 and 1,000,000,000 units which were registered with the SEC on August 12, 2009. Units offered by USNG in the subsequent offerings were sold by it for cash at the units’ per unit NAV as described in the applicable prospectus. On March 8, 2011, after the close of trading on the NYSE Arca, USNG effected a 2-for-1 reverse unit split and post-split units of USNG began trading on March 9, 2011. As a result of the reverse unit split, every two pre-split units of USNG were automatically exchanged for one post-split unit. Immediately prior to the reverse unit split, there were 447,200,000 units of USNG issued and outstanding, representing a per unit NAV of $5.16. Immediately after the reverse unit split, the number of issued and outstanding units of USNG decreased to 223,600,000, not accounting for fractional units, and the per unit NAV increased to $10.31. On February 21, 2012, after the close of trading on the NYSE Arca, USNG effected a 4-for-1 reverse unit split and post-split units of USNG began trading on February 22, 2012. As a result of the reverse unit split, every four pre-split units of USNG were automatically exchanged for one post-split unit. Immediately prior to the reverse unit split, there were 174,297,828 units of USNG issued and outstanding, representing a per unit NAV of $5.51. Immediately after the reverse unit split, the number of issued and outstanding units of USNG decreased to 43,574,457, not accounting for fractional units, and the per unit NAV increased to $22.04. As of December 31, 2012, USNG had issued 1,229,400,000 units, 62,866,476 of which were outstanding. As of December 31, 2012, there were 250,600,000 units registered but not yet issued.

More units may have been issued by USNG than are outstanding due to the redemption of units. Unlike funds that are registered under the 1940 Act, units that have been redeemed by USNG cannot be resold by USNG. As a result, USNG contemplates that additional offerings of its units will be registered with the SEC in the future in anticipation of additional issuances and redemptions.

As of December 31, 2012, USNG had the following authorized purchasers: ABN Amro, Banc of America Securities LLC, Citadel Securities LLC, Citigroup Global Markets Inc., Credit Suisse Securities USA LLC, Deutsche Bank Securities Inc., Fimat USA LLC, Goldman Sachs & Company, Goldman Sachs Execution & Clearing LP, JP Morgan Securities Inc., Merrill Lynch Professional Clearing Corp., Morgan Stanley & Company Inc., Nomura Securities International Inc., RBC Capital Markets Corporation, SG Americas Securities LLC, Virtu Financial Capital Markets and Virtu Financial DB LLC.

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For the Year Ended December 31, 2012 Compared to the Years Ended December 31, 2011 and 2010

As of December 31, 2012, the total unrealized loss on natural gas Futures Contracts, cleared swap contracts and over-the-counter swap contracts owned or held on that day was $18,067,782 and USNG established cash deposits and investments in Treasuries and money market funds that were equal to $1,245,314,221. USNG held 88.37% of its cash assets in overnight deposits and investments in Treasuries and money market funds at the Custodian, while 11.63% of the cash balance was held as investments in Treasuries and as margin deposits for the Futures Contracts purchased. The ending per unit NAV on December 31, 2012 was $18.87.

By comparison, as of December 31, 2011, the total unrealized loss on natural gas Futures Contracts, cleared swap contracts and over-the-counter swap contracts owned or held on that day was $61,797,997 and USNG established cash deposits and investments in Treasuries and money market funds that were equal to $1,145,306,865. USNG held 81.96% of its cash assets in overnight deposits and investments in Treasuries and money market funds at the Custodian, while 18.04% of the cash balance was held as investments in Treasuries and as margin deposits for the Futures Contracts purchased. The increase in cash assets in overnight deposits and investments in Treasuries and money market funds for December 31, 2012 as compared to December 31, 2011, was the result of USNG’s larger size during the year ended December 31, 2012 as measured by total net assets. The ending per unit NAV on December 31, 2011 was $25.88*. The decrease in the per unit NAV for December 31, 2012, as compared to December 31, 2011, was primarily due to the impact of contango and the related decline in the value of the Futures Contracts, cleared swap contracts and over-the-counter swap contracts that USNG had invested in between the year ended December 31, 2011 and the year ended December 31, 2012.

* Adjusted to give effect to the reverse unit split of 4-for-1 executed on February 21, 2012.

By comparison, as of December 31, 2010, the total unrealized gain on natural gas Futures Contracts, cleared swap contracts and over-the-counter swap contracts owned or held on that day was $114,605,506 and USNG established cash deposits and investments in Treasuries and money market funds that were equal to $2,635,369,994. USNG held 88.06% of its cash assets in overnight deposits and investments Treasuries and money market funds at the Custodian, while 11.94% of the cash balance was held as margin deposits for the Futures Contracts purchased. The decrease in cash assets in overnight deposits and investments in Treasuries and money market funds for December 31, 2011 as compared to December 31, 2010, was the result of USNG’s smaller size during the year ended December 31, 2011 as measured by total net assets. The ending per unit NAV on December 31, 2010 was $48.00**. The decrease in the per unit NAV for December 31, 2011, as compared to December 31, 2010, was primarily a result of sharply lower prices for natural gas and the related decline in the value of the Futures Contracts, cleared swap contracts and over-the-counter swap contracts that USNG had invested in between the year ended December 31, 2010 and the year ended December 31, 2011.

** Adjusted to give effect to the reverse unit split of 2-for-1 executed on March 8, 2011 and the reverse unit split of 4-for-1 executed on February 21, 2012.

Portfolio Expenses. USNG’s expenses consist of investment management fees, brokerage fees and commissions, certain offering costs, licensing fees, the fees and expenses of the independent directors of USCF and expenses relating to tax accounting and reporting requirements. The management fee that USNG pays to USCF is calculated as a percentage of the total net assets of USNG. For total net assets up to $1 billion, the management fee is 0.60%. For total net assets over $1 billion, the management fee is 0.50% on the incremental amount of total net assets. The fee is accrued daily and paid monthly.

During the year ended December 31, 2012, the average daily total net assets of USNG were $1,040,686,592. The management fee incurred by USNG during the year ended December 31, 2012 amounted to $6,154,688, which was calculated at the 0.60% rate for total net assets up to and including $1 billion and at the rate of 0.50% on total net assets over $1 billion, and accrued daily. Management fees as a percentage of average daily total net assets averaged 0.59% over the course of the year ended December 31, 2012. By comparison, during the year ended December 31, 2011, the average daily total net assets of USNG were $1,814,982,597. The management fee paid by USNG during the year ended December 31, 2011 amounted to $10,074,913, which was calculated at the 0.60% rate for total net assets up to and including $1 billion and at the rate of 0.50% on total net assets over $1 billion, and accrued daily. Management fees as a percentage of average daily total net assets averaged 0.55% over the course of the year ended December 31, 2011. By comparison, during the year ended December 31, 2010, the average daily total net assets of USNG were $3,013,443,744. The management fee paid by USNG during the year ended December 31, 2010 amounted to $16,067,219, which was calculated at the 0.60% rate for total net assets up to and including $1 billion and at the rate of 0.50% on total net assets over $1 billion, and accrued daily. Management fees as a percentage of average daily total net assets averaged 0.53% over the course of the year ended December 31, 2010. USNG’s management fees as a percentage of average daily total net assets were higher for the year ended December 31, 2012 as compared to the years ended December 31, 2011 and 2010 due to the fact that the proportion of total net assets that exceeded $1 billion that were charged at the lower 0.50% rate was smaller during the year ended December 31, 2012.

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In addition to the management fee, USNG pays all brokerage fees and other expenses, including tax reporting costs, licensing fees for the use of intellectual property, ongoing registration or other fees paid to the SEC, FINRA and any other regulatory agency in connection with offers and sales of its units subsequent to the initial offering and all legal, accounting, printing and other expenses associated therewith. The total of these fees and expenses for the year ended December 31, 2012 was $5,128,465, as compared to $7,480,112 for the year ended December 31, 2011 and $9,773,026 for the year ended December 31, 2010. The decrease in total expenses excluding management fees for the year ended December 31, 2012 as compared to the year ended December 31, 2011, was primarily due to reduced trading activity and reduced variable costs resulting from USNG’s lower average daily total net assets during the year ended December 31, 2012. The decrease in total expenses excluding management fees for the year ended December 31, 2011 as compared to the year ended December 31, 2010, was primarily due to reduced activity in USNG, resulting in reduced costs associated with the registration and offering of additional units and decreased brokerage fees, legal expenses and tax reporting costs. For the year ended December 31, 2012, USNG incurred $(19,388) in ongoing registration fees and other expenses relating to the registration and offering of additional units. By comparison, for the years ended December 31, 2011 and 2010, USNG incurred $113,150 and $93,970, respectively, in ongoing registration fees and other expenses relating to the registration and offering of additional units. The decrease in registration fees and expenses incurred by USNG for the year ended December 31, 2012, as compared to the year ended December 31, 2011, was due to the fact that these expenses were completely amortized by December 31, 2011. The positive impact (negative expense) during the year ended December 31, 2012 was a result of an over accrual of a portion of the registration fees and expenses for the year ended December 31, 2011 that was subsequently adjusted during the year ended December 31, 2012. The increase in registration fees and expenses incurred by USNG for the year ended December 31, 2011 as compared to the year ended December 31, 2010, was primarily due to a slightly higher estimate for creation activity in the units of USNG.

USNG is responsible for paying its portion of the directors’ and officers’ liability insurance of USNG and the Related Public Funds and the fees and expenses of the independent directors who also serve as audit committee members of USNG and the Related Public Funds organized as limited partnerships and, as of July 8, 2011, the Related Public Funds organized as a series of a Delaware statutory trust. USNG shares the fees and expenses on a pro rata basis with each Related Public Fund, as described above, based on the relative assets of each fund computed on a daily basis. These fees and expenses for the year ended December 31, 2012 amounted to a total of $540,586 for USNG and the Related Public Funds. USNG’s portion of such fees and expenses for the year ended December 31, 2012 was $172,838. By comparison, for the year ended December 31, 2011, these fees and expenses amounted to a total of $607,582 for USNG and the Related Public Funds. USNG’s portion of such fees and expenses for the year ended December 31, 2011 was $290,377. The decrease in directors’ fees and expenses for the year ended December 31, 2012, as compared to the year ended December 31, 2011 was primarily due to the non-incurrence of the independent directors’ deferred compensation expense for the year ended December 31, 2012, which was amortized during the years ended December 31, 2011 and 2010. By comparison, for the year ended December 31, 2010, these fees and expenses amounted to a total of $1,107,140 for USNG and the Related Public Funds, except USCI, CPER, USAG and USMI. USNG’s portion of such fees and expenses for the year ended December 31, 2010 was $629,670. The decrease in directors’ fees and expenses for the year ended December 31, 2011, as compared to the year ended December 31, 2010, was primarily due to the non-incurrence of the independent directors’ deferred compensation expense for the year ended December 31, 2011, the majority of which was amortized in the year ended December 31, 2010. Effective as of April 1, 2010, USNG became responsible for paying its portion of any payments that may become due to the independent directors pursuant to the deferred compensation agreements entered into between the independent directors, USCF, USNG and the Related Public Funds, except for USCI, USAG, CPER and USMI.

USNG also incurs commissions to brokers for the purchase and sale of Futures Contracts, Other Natural Gas-Related Investments or Treasuries. During the year ended December 31, 2012, total commissions accrued to brokers amounted to $3,499,652. Of this amount, approximately $2,954,424 was a result of rebalancing costs and approximately $545,228 was the result of trades necessitated by creation and redemption activity. By comparison, during the year ended December 31, 2011, total commissions accrued to brokers amounted to $4,718,066. Of this amount, approximately $4,442,086 was a result of rebalancing costs and approximately $275,980 was the result of trades necessitated by creation and redemption activity. By comparison, during the year ended December 31, 2010, total commissions accrued to brokers amounted to $6,257,135. Of this amount, approximately $5,931,931 was a result of rebalancing costs and $325,204 was the result of trades necessitated by creation and redemption activity. The decrease in the total commissions accrued to brokers for the year ended December 31, 2012 as compared to the year ended December 31, 2011, was primarily a function of decreased brokerage fees due to a lower number of Natural Gas Interests being held and traded during the year ended December 31, 2012. The decrease in the total commissions accrued to brokers for the year ended December 31, 2011 as compared to the year ended December 31, 2010, was primarily a function of decreased brokerage fees due to a fewer number of Natural Gas Interests being held and traded. As an annualized percentage of average daily total net assets, the figure for the year ended December 31, 2012 represents approximately 0.33% of average daily total net assets. By comparison, the figure for the year ended December 31, 2011 represented approximately 0.26% of average daily total net assets and the figure for the year ended December 31, 2010 represented approximately 0.21% of average daily total net assets. However, there can be no assurance that commission costs and portfolio turnover will not cause commission expenses to rise in future quarters.

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USNG incurred $819,038 in transaction costs for the year ended December 31, 2012 as compared to $3,585,894 in transaction costs for the year ended December 31, 2011 and $6,881,907 in transaction costs for the year ended December 31, 2010. USNG’s transaction costs were lower during the year ended December 31, 2012 as compared to the years ended December 31, 2011 and 2010, due to reduced investment in Other Natural Gas-Related Investments, including over-the-counter swap transactions, during the year ended December 31, 2012. However, these costs remain somewhat higher as compared to those for other exchange-traded Natural Gas Interests.

The fees and expenses associated with USNG’s audit expenses and tax accounting and reporting requirements are paid by USNG. These costs are estimated to be $1,900,000 for the year ended December 31, 2012.

Dividend and Interest Income. USNG seeks to invest its assets such that it holds Futures Contracts and Other Natural Gas-Related Investments in an amount equal to the total net assets of its portfolio. Typically, such investments do not require USNG to pay the full amount of the contract value at the time of purchase, but rather require USNG to post an amount as a margin deposit against the eventual settlement of the contract. As a result, USNG retains an amount that is approximately equal to its total net assets, which USNG invests in Treasuries, cash and/or cash equivalents. This includes both the amount on deposit with the FCM as margin and in Treasuries, as well as unrestricted cash and cash equivalents held with USNG’s Custodian. The Treasuries, cash and/or cash equivalents earn income that accrues on a daily basis. For the year ended December 31, 2012, USNG earned $369,153 in dividend and interest income on such Treasuries, cash and/or cash equivalents. Based on USNG’s average daily total net assets, this was equivalent to an annualized yield of approximately 0.03%. USNG purchased Treasuries during the year ended December 31, 2012 and also held cash and/or cash equivalents during this time period. By comparison, for the years ended December 31, 2011 and 2010, USNG earned $431,129 and $1,364,576, respectively, in dividend and interest income on such Treasuries, cash and/or cash equivalents. Based on USNG’s average daily total net assets, this was equivalent to an annualized yield of approximately 0.02% and 0.05%, respectively. USNG purchased Treasuries during the years ended December 31, 2011 and 2010 and also held cash and/or cash equivalents during these time periods. Interest rates on short-term investments held by USNG, including cash, cash equivalents and Treasuries, were higher during the year ended December 31, 2012 compared to the year ended December 31, 2011 and lower compared to the year ended December 31, 2010. As a result, the amount of income earned by USNG as a percentage of average daily total net assets was higher during the year ended December 31, 2012 as compared to the year ended December 31, 2011 and lower as compared to the year ended December 31, 2010.

For the Three Months Ended December 31, 2012 Compared to the Three Months Ended December 31, 2011 and 2010

Portfolio Expenses. During the three months ended December 31, 2012, the average daily total net assets of USNG were $1,206,363,667. The management fee incurred by USNG during the period amounted to $1,767,561, which was calculated at the 0.60% rate for total net assets up to and including $1 billion and at the rate of 0.50% on total net assets over $1 billion, and accrued daily. Management fees as a percentage of average daily total net assets averaged 0.58% over the course of the three months ended December 31, 2012.

By comparison, during the three months ended December 31, 2011, the average daily total net assets of USNG were $1,281,021,694. The management fee paid by USNG during the period amounted to $1,866,493, which was calculated at the 0.60% rate for total net assets up to and including $1 billion and at the rate of 0.50% of total net assets over $1 billion, and accrued daily. Management fees as a percentage of average daily total net assets averaged 0.58% over the course of the three months ended December 31, 2011.

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By comparison, during the three months ended December 31, 2010, the average daily total net assets of USNG were $2,592,712,195. The management fee paid by USNG for the three months ended December 31, 2010 amounted to $3,519,583, which was calculated at the 0.60% rate for total net assets up to and including $1 billion and at the rate of 0.50% of total net assets over $1 billion, and accrued daily. Management fees as a percentage of average daily total net assets averaged 0.54% over the course of the three months ended December 31, 2010. USNG’s management fees as a percentage of average daily total net assets were higher for the three months ended December 31, 2012 and 2011 compared to the three months ended December 31, 2010, due to the fact that the proportion of total net assets that exceeded $1 billion that were charged at the lower 0.50% rate was smaller during the three months ended December 31, 2012 and 2011.

In addition to the management fee, USNG pays all brokerage fees and other expenses, including tax reporting costs, licensing fees for the use of intellectual property, ongoing registration or other fees paid to the SEC, FINRA and any other regulatory agency in connection with offers and sales of its units subsequent to the initial offering and all legal, accounting, printing and other expenses associated therewith. The total of these fees and expenses for the three months ended December 31, 2012 was $1,216,366, as compared to $1,786,701 for the three months ended December 31, 2011 and $2,118,484 for the three months ended December 31, 2010. The decrease in total expenses excluding management fees for the three months ended December 31, 2012, as compared to the three months ended December 31, 2011, was primarily due to reduced trading activity and reduce variable costs resulting from USNG’s lower average daily total net assets during the three months ended December 31, 2012. The decrease in total expenses excluding management fees for the three months ended December 31, 2011 as compared to the three months ended December 31, 2010, was primarily due to the relative size of USNG and activity that resulted from its decreased size, including decreased brokerage fees, decreased transaction costs for over-the-counter swaps, decreased licensing fees and decreased tax reporting costs due to the fewer number of unitholders during the three months ended December 31, 2011. For the three months ended December 31, 2012, USNG incurred $0 in ongoing registration fees and other expenses relating to the registration and offering of additional units. By comparison, for the three months ended December 31, 2011 and 2010, USNG incurred $28,520 and $25,760, respectively, in ongoing registration fees and other expenses relating to the registration and offering of additional units. The decrease in registration fees and expenses incurred by USNG for the three months ended December 31, 2012 as compared to the three months ended December 31, 2011, was due to the fact that these expenses were completely amortized by December 31, 2011. The increase in registration fees and expenses incurred by USNG for the three months ended December 31, 2011 as compared to the three months ended December 31, 2010, was primarily due to a slightly higher estimate for creation activity in the units of USNG.

USNG is responsible for paying its portion of the directors’ and officers’ liability insurance of USNG and the Related Public Funds and the fees and expenses of the independent directors who also serve as audit committee members of USNG and the Related Public Funds organized as limited partnerships and, as of July 8, 2011, the Related Public Funds organized as a series of a Delaware statutory trust. USNG shares the fees and expenses on a pro rata basis with each Related Public Fund, as described above, based on the relative assets of each fund computed on a daily basis. These fees and expenses for the year ended December 31, 2012 amounted to a total of $540,586 for USNG and the Related Public Funds. USNG’s portion of such fees and expenses for the year ended December 31, 2012 was $172,838.

USNG also incurs commissions to brokers for the purchase and sale of Futures Contracts, Other Natural Gas-Related Investments or Treasuries. During the three months ended December 31, 2012, total commissions accrued to brokers amounted to $700,112. Of this amount, approximately $608,829 was a result of rebalancing costs and approximately $91,283 was the result of trades necessitated by creation and redemption activity. By comparison, during the three months ended December 31, 2011, total commissions accrued to brokers amounted to $1,133,160. Of this amount, approximately $1,081,600 was a result of rebalancing costs and approximately $51,560 was the result of trades necessitated by creation and redemption activity. By comparison, during the three months ended December 31, 2010, total commissions accrued to brokers amounted to $1,553,047. Of this amount, approximately $102,316 was a result of rebalancing costs and approximately $1,450,731 was the result of trades necessitated by creation and redemption activity. The decrease in total commissions accrued to brokers for the three months ended December 31, 2012, as compared to the three months ended December 31, 2011, was primarily a function of decreased brokerage fees due to a lower number of Natural Gas Interests being held and traded during the three months ended December 31, 2012. The decrease in total commissions accrued to brokers for the three months ended December 31, 2011 as compared to the three months ended December 31, 2010, was primarily a function of decreased brokerage fees due to a lower number of Natural Gas Interests being held and traded as a result of USNG’s decreased size during the three months ended December 31, 2011. As an annualized percentage of average daily total net assets, the figure for the three months ended December 31, 2012 represents approximately 0.23% of average daily total net assets. By comparison, the figure for the three months ended December 31, 2011 represented approximately 0.35% of average daily total net assets and the figure for the three months ended December 31, 2010 represented approximately 0.24% of average daily total net assets. However, there can be no assurance that commission costs and portfolio turnover will not cause commission expenses to rise in future quarters.

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USNG incurred $167,836 in transaction costs for the three months ended December 31, 2012 as compared to $425,747 in transaction costs for the three months ended December 31, 2011 and $1,356,390 in transaction costs for the three months ended December 31, 2010. USNG’s transaction costs were lower during the three months ended December 31, 2012 compared to the three months ended December 31, 2011 and December 31, 2010, due to reduced investment in Other Natural Gas-Related Investments, including over-the-counter swap transactions, during the three months ended December 31, 2012. However, these costs remain somewhat higher as compared to those for other exchange-traded Natural Gas Interests.

The fees and expenses associated with USNG’s audit expenses and tax accounting and reporting requirements are paid by USNG. These costs are estimated to be $1,900,000 for the year ended December 31, 2012.

Dividend and Interest Income. USNG seeks to invest its assets such that it holds Futures Contracts and Other Natural Gas-Related Investments in an amount equal to the total net assets of its portfolio. Typically, such investments do not require USNG to pay the full amount of the contract value at the time of purchase, but rather require USNG to post an amount as a margin deposit against the eventual settlement of the contract. As a result, USNG retains an amount that is approximately equal to its total net assets, which USNG invests in Treasuries, cash and/or cash equivalents. This includes both the amount on deposit with the FCM as margin and in Treasuries, as well as unrestricted cash and cash equivalents held with USNG’s Custodian. The Treasuries, cash and/or cash equivalents earn income that accrues on a daily basis. For the three months ended December 31, 2012, USNG earned $136,454 in dividend and interest income on such Treasuries, cash and/or cash equivalents. Based on USNG’s average daily total net assets, this was equivalent to an annualized yield of approximately 0.04%. USNG purchased Treasuries during the three months ended December 31, 2012 and also held cash and/or cash equivalents during this time period. By comparison, for the three months ended December 31, 2011 and 2010, USNG earned $60,591 and $346,092, respectively, in dividend and interest income on such Treasuries, cash and/or cash equivalents. Based on USNG’s average daily total net assets, this was equivalent to an annualized yield of approximately 0.02% and 0.05%, respectively. USNG purchased Treasuries during the three months ended December 31, 2011 and 2010 and also held cash and/or cash equivalents during these time periods. Interest rates on short-term investments held by USNG, including cash, cash equivalents and Treasuries, were higher during the three months ended December 31, 2012 compared to the three months ended December 31, 2011 and lower compared to the three months ended December 31, 2010. As a result, the amount of income earned by USNG as a percentage of average daily total net assets was higher during the three months ended December 31, 2012 as compared to the three months ended December 31, 2011 and lower as compared to the three months ended December 31, 2010.

Tracking USNG’s Benchmark. USCF seeks to manage USNG’s portfolio such that average daily changes in its per unit NAV, on a percentage basis, closely track the average daily changes in the price of the Benchmark Futures Contract, also on a percentage basis. Specifically, USCF seeks to manage the portfolio such that over any rolling period of 30 valuation days, the average daily change in USNG’s per unit NAV is within a range of 90% to 110% (0.9 to 1.1) of the average daily change in the price of the Benchmark Futures Contract. As an example, if the average daily movement of the price of the Benchmark Futures Contract for a particular 30-valuation day time period was 0.50% per day, USCF would attempt to manage the portfolio such that the average daily movement of the per unit NAV during that same time period fell between 0.45% and 0.55% (i.e., between 0.9 and 1.1 of the benchmark’s results). USNG’s portfolio management goals do not include trying to make the nominal price of USNG’s per unit NAV equal to the nominal price of the current Benchmark Futures Contract or the spot price for natural gas. USCF believes that it is not practical to manage the portfolio to achieve such an investment goal when investing in listed natural gas Futures Contracts and Other Natural Gas-Related Investments.

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Since the commencement of the offering of USNG units to the public on April 18, 2007 to December 31, 2012, the simple average daily change in the Benchmark Futures Contract was (0.166)%, while the simple average daily change in the per unit NAV of USNG over the same time period was (0.168)%. The average daily difference was 0.002% (or 0.2 basis points, where 1 basis point equals of  ¹/₁₀₀ 1%). As a percentage of the daily movement of the Benchmark Futures Contract, the average error in daily tracking by the per unit NAV was (0.382)%, meaning that over this time period USNG’s tracking error was within the plus or minus 10% range established as its benchmark tracking goal.

*PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

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*PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

An alternative tracking measurement of the return performance of USNG versus the return of its Benchmark Futures Contract can be calculated by comparing the actual return of USNG, measured by changes in its per unit NAV, versus the expected changes in its per unit NAV under the assumption that USNG’s returns had been exactly the same as the daily changes in its Benchmark Futures Contract.

For the year ended December 31, 2012, the actual total return of USNG as measured by changes in its per unit NAV was (27.09)%. This is based on an initial per unit NAV of $25.88* on December 31, 2011 and an ending per unit NAV as of December 31, 2012 of $18.87. During this time period, USNG made no distributions to its unitholders. However, if USNG’s daily changes in its per unit NAV had instead exactly tracked the changes in the daily total return of the Benchmark Futures Contract, USNG would have had an estimated per unit NAV of $19.08 as of December 31, 2012, for a total return over the relevant time period of (26.28)%. The difference between the actual per unit NAV total return of USNG of (27.09)% and the expected total return based on the Benchmark Futures Contract of (26.28)% was an error over the time period of (0.81)%, which is to say that USNG’s actual total return underperformed the benchmark result by that percentage. USCF believes that a portion of the difference between the actual total return and the expected benchmark total return can be attributed to the net impact of the expenses that USNG pays, offset in part by the income that USNG collects on its cash and cash equivalent holdings. During the year ended December 31, 2012, USNG earned dividend and interest income of $369,153, which is equivalent to a weighted average income rate of approximately 0.03% for such period. In addition, during the year ended December 31, 2012, USNG also collected $216,000 from its Authorized Purchasers for creating or redeeming baskets of units. This income also contributed to USNG’s actual total return. During the year ended December 31, 2012, USNG incurred total expenses of $11,283,153. Income from dividends and interest and Authorized Purchaser collections net of expenses was $(10,698,000), which is equivalent to a weighted average net income rate of approximately (1.03)% for the year ended December 31, 2012.

* Adjusted to give effect to the reverse unit split of 4-for-1 executed on February 21, 2012.

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By comparison, for the year ended December 31, 2011, the actual total return of USNG as measured by changes in its per unit NAV was (46.08)%. This was based on an initial per unit NAV of $48.00* on December 31, 2010 and an ending per unit NAV as of December 31, 2011 of $25.88**. During this time period, USNG made no distributions to its unitholders. However, if USNG’s daily changes in its per unit NAV had instead exactly tracked the changes in the daily total return of the Benchmark Futures Contract, USNG would have had an estimated per unit NAV of $26.20** as of December 31, 2011, for a total return over the relevant time period of (45.42)%. The difference between the actual per unit NAV total return of USNG of (46.08)% and the expected total return based on the Benchmark Futures Contract of (45.42)% was an error over the time period of (0.66)%, which is to say that USNG’s actual total return underperformed the benchmark result by that percentage. USCF believes that a portion of the difference between the actual total return and the expected benchmark total return can be attributed to the net impact of the expenses that USNG paid, offset in part by the income that USNG collected on its cash and cash equivalent holdings. During the year ended December 31, 2011, USNG earned dividend and interest income of $431,129, which is equivalent to a weighted average income rate of approximately 0.02% for such period. In addition, during the year ended December 31, 2011, USNG also collected $146,000 from its Authorized Purchasers for creating or redeeming baskets of units. This income also contributed to USNG’s actual total return. During the year ended December 31, 2011, USNG incurred total expenses of $17,555,025. Income from dividends and interest and Authorized Purchaser collections net of expenses was $(16,977,896), which is equivalent to a weighted average net income rate of approximately (0.94)% for the year ended December 31, 2011.

* Adjusted to give effect to the reverse unit split of 2-for-1 executed on March 8, 2011 and the reverse unit split of 4-for-1 executed on February 21, 2012.

** Adjusted to give effect to the reverse unit split of 4-for-1 executed on February 21, 2012.

By comparison, for the year ended December 31, 2010, the actual total return of USNG as measured by changes in its per unit NAV was (40.42)%. This was based on an initial per unit NAV of $80.52* on December 31, 2009 and an ending per unit NAV as of December 31, 2010 of $48.00*. During this time period, USNG made no distributions to its unitholders. However, if USNG’s daily changes in its per unit NAV had instead exactly tracked the changes in the daily total return of the Benchmark Futures Contract, USNG would have had an estimated per unit NAV of $48.52* as of December 31, 2010, for a total return over the relevant time period of (39.74)%. The difference between the actual per unit NAV total return of USNG of (40.42)% and the expected total return based on the Benchmark Futures Contract of (39.74)% was an error over the time period of (0.68)%, which is to say that USNG’s actual total return underperformed the benchmark result by that percentage. USCF believes that a portion of the difference between the actual total return and the expected benchmark total return can be attributed to the net impact of the expenses that USNG paid, offset in part by the income that USNG collected on its cash and cash equivalent holdings. During the year ended December 31, 2010, USNG earned dividend and interest income of $1,364,576, which is equivalent to a weighted average income rate of approximately 0.05% for such period. In addition, during the year ended December 31, 2010, USNG also collected $204,000 from its Authorized Purchasers for creating or redeeming baskets of units. This income also contributed to USNG’s actual total return. During the year ended December 31, 2010, USNG incurred total expenses of $25,840,245. Income from dividends and interest and Authorized Purchaser collections net of expenses was $(24,271,669), which is equivalent to a weighted average net income rate of approximately (0.81)% for the year ended December 31, 2010.

* Adjusted to give effect to the reverse unit split of 2-for-1 executed on March 8, 2011 and the reverse unit split of 4-for-1 executed on February 21, 2012.

There are currently three factors that have impacted or are most likely to impact USNG’s ability to accurately track its Benchmark Futures Contract.

First, USNG may buy or sell its holdings in the then current Benchmark Futures Contract at a price other than the closing settlement price of that contract on the day during which USNG executes the trade. In that case, USNG may pay a price that is higher, or lower, than that of the Benchmark Futures Contract, which could cause the daily changes in the per unit NAV of USNG to either be too high or too low relative to the daily changes in the Benchmark Futures Contract. During the year ended December 31, 2012, USCF attempted to minimize the effect of these transactions by seeking to execute its purchase or sale of the Benchmark Futures Contract at, or as close as possible to, the end of the day settlement price. However, it may not always be possible for USNG to obtain the closing settlement price and there is no assurance that failure to obtain the closing settlement price in the future will not adversely impact USNG’s attempt to track the Benchmark Futures Contract over time.

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Second, USNG earns dividend and interest income on its cash, cash equivalents and Treasuries. USNG is not required to distribute any portion of its income to its unitholders and did not make any distributions to unitholders during the year ended December 31, 2012. Interest payments, and any other income, were retained within the portfolio and added to USNG’s NAV. When this income exceeds the level of USNG’s expenses for its management fee, brokerage commissions and other expenses (including ongoing registration fees, licensing fees and the fees and expenses of the independent directors of USCF), USNG will realize a net yield that will tend to cause daily changes in the per unit NAV of USNG to track slightly higher than daily changes in the Benchmark Futures Contract. During the year ended December 31, 2012, USNG earned, on an annualized basis, approximately 0.03% on its cash and cash equivalent holdings. It also incurred cash expenses on an annualized basis of approximately 0.59% for management fees, approximately 0.33% in brokerage commission costs related to the purchase and sale of futures contracts and approximately 0.16% for other expenses. The foregoing fees and expenses resulted in a net yield on an annualized basis of approximately (1.05)% and affected USNG’s ability to track its benchmark. If short-term interest rates rise above the current levels, the level of deviation created by the yield would decrease. Conversely, if short-term interest rates were to decline, the amount of error created by the yield would increase. When short-term yields drop to a level lower than the combined expenses of the management fee and the brokerage commissions, then the tracking error becomes a negative number and would tend to cause the daily returns of the per unit NAV to underperform the daily returns of the Benchmark Futures Contract. USCF anticipates that interest rates will continue to remain at historical lows and, therefore, it is anticipated that fees and expenses paid by USNG will continue to be higher than interest earned by USNG. As such, USCF anticipates that USNG will continue to underperform its benchmark until such time when interest earned at least equals or exceeds the fees and expenses paid by USNG.

Third, USNG may hold Other Natural Gas-Related Investments in its portfolio that may fail to closely track the Benchmark Futures Contract’s total return movements. In that case, the error in tracking the Benchmark Futures Contract could result in daily changes in the per unit NAV of USNG that are either too high, or too low, relative to the daily changes in the Benchmark Futures Contract. During the year ended December 31, 2012, USNG held Other Natural Gas-Related Investments. These holdings included a financially settled natural gas futures contract traded on NYMEX whose settlement price tracks the settlement price of the Benchmark Futures Contract. USNG also held investments in cleared swaps traded on the ICE Futures whose settlement price also tracks the settlement price of the Benchmark Futures Contract and fully-collateralized over-the-counter swaps designed to track the settlement price of the Benchmark Futures Contract. Due, in part, to the size of USNG and its obligations to comply with regulatory limits, USNG has invested in Other Natural Gas-Related Investments, such as over-the-counter swaps, which have increased transaction-related expenses and may result in increased tracking error. Over-the-counter swaps increase transaction-related expenses due to the fact that USNG must pay to the swap counterparty certain fees that USNG does not have to pay for transactions executed on an exchange. Finally, due to potential regulatory limitations, USNG may determine to hold greater amounts of cash and cash equivalents and lesser amounts of Natural Gas Interests, if it determines that will most appropriately satisfy USNG’s investment objective. Holding more cash and cash equivalents and less Natural Gas Interests for some period of time may result in increased tracking error. There are additional Other Natural Gas-Related Investments that USNG is permitted to invest in whose price movements may not track the settlement price of the Benchmark Futures Contract.

Term Structure of Natural Gas Futures Prices and the Impact on Total Returns. Several factors determine the total return from investing in a futures contract position. One factor that impacts the total return that will result from investing in near month futures contracts and “rolling” those contracts forward each month is the price relationship between the current near month contract and the next month contract. For example, if the price of the near month contract is higher than the next month contract (a situation referred to as “backwardation” in the futures market), then absent any other change there is a tendency for the price of a next month contract to rise in value as it becomes the near month contract and approaches expiration. Conversely, if the price of a near month contract is lower than the next month contract (a situation referred to as “contango” in the futures market), then absent any other change there is a tendency for the price of a next month contract to decline in value as it becomes the near month contract and approaches expiration.

As an example, assume that the price of natural gas for immediate delivery (the “spot price”) was $7 per MMBtu, and the value of a position in the near month futures contract was also $7. Over time, the price of 10,000 MMBtu of natural gas will fluctuate based on a number of market factors, including demand for natural gas relative to its supply. The value of the near month contract will likewise fluctuate in reaction to a number of market factors. If investors seek to maintain their position in a near month contract and not take delivery of the natural gas, every month they must sell their current near month contract as it approaches expiration and invest in the next month contract.

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If the futures market is in backwardation, e.g., when the expected price of natural gas in the future would be less, the investor would be buying a next month contract for a lower price than the current near month contract. Using the $7 per MMBtu price above to represent the front month price, the price of the next month contract could be $6.86 per barrel, that is, 2% cheaper than the front month contract. Hypothetically, and assuming no other changes to either prevailing natural gas prices or the price relationship between the spot price, the near month contract and the next month contract (and ignoring the impact of commission costs and the income earned on cash and/or cash equivalents), the value of the $6.86 next month contract would rise as it approaches expiration and becomes the new near month contract with a price of $7. In this example, the value of an investment in the second month contract would tend to rise faster than the spot price of natural gas, or fall slower. As a result, it would be possible in this hypothetical example for the spot price of natural gas to have risen 10% after some period of time, while the value of the investment in the second month futures contract would have risen 12%, assuming backwardation is large enough or enough time has elapsed. Similarly, the spot price of natural gas could have fallen 10% while the value of an investment in the futures contract could have fallen only 8%. Over time, if backwardation remained constant, the difference would continue to increase.

If the futures market is in contango, the investor would be buying a next month contract for a higher price than the current near month contract. Using again the $7 per MMBtu price above to represent the front month price, the price of the next month contract could be $7.14 per barrel, that is, 2% more expensive than the front month contract. Hypothetically, and assuming no other changes to either prevailing natural gas prices or the price relationship between the spot price, the near month contract and the next month contract (and ignoring the impact of commission costs and the income earned on cash and/or cash equivalents), the value of the next month contract would fall as it approaches expiration and becomes the new near month contract with a price of $7. In this example, it would mean that the value of an investment in the second month would tend to rise slower than the spot price of natural gas, or fall faster. As a result, it would be possible in this hypothetical example for the spot price of natural gas to have risen 10% after some period of time, while the value of the investment in the second month futures contract will have risen only 8%, assuming contango is large enough or enough time has elapsed. Similarly, the spot price of natural gas could have fallen 10% while the value of an investment in the second month futures contract could have fallen 12%. Over time, if contango remained constant, the difference would continue to increase.

The chart below compares the price of the near month contract to the average price of the near 12 month contracts over the last 10 years for natural gas. When the price of the near month contract is higher than the average price of the near 12 month contracts, the market would be described as being in backwardation. When the price of the near month contract is lower than the average price of the near 12 month contracts, the market would be described as being in contango. Although the prices of the near month contract and the average price of the near 12 month contracts do tend to move up or down together, it can be seen that at times the near month prices are clearly higher than the average price of the near 12 month contracts (backwardation), and other times they are below the average price of the near 12 month contracts (contango). In addition, investors can observe that natural gas prices, both front month and the average of the near 12 months, often display a seasonal pattern in which the price of natural gas tends to rise in the early winter months and decline in the summer months. This mirrors the physical demand for natural gas, which typically peaks in the winter.

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PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

An alternative way to view backwardation and contango data over time is to subtract the dollar price of the near month natural gas Futures Contract from the dollar price of the near 12 month natural gas Futures Contracts. If the resulting number is a positive number, then the near month price is higher than the average price of the near 12 months and the market could be described as being in backwardation. If the resulting number is a negative number, then the near month price is lower than the average price of the near 12 months and the market could be described as being in contango. The chart below shows the results from subtracting the average dollar price of the near 12 month contracts from the near month price for the 10 year period between December 31, 2003 and December 31, 2012. Investors will note that the natural gas market spent time in both backwardation and contango. Investors will further note that the markets display a seasonal pattern that corresponds to the seasonal demand patterns for natural gas above. That is, in many, but not all, cases the average price of the near 12 month contracts is higher than the near month during the approach to the winter months as the price of natural gas for delivery in those winter months rises on expectations of demand. At the same time, the price of the near month, when that month is just before the onset of winter, does not rise as far or as fast as the average price of the near 12 month contracts whose delivery falls during the winter season.

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PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

An investment in a portfolio that involved owning only the near month contract would likely produce a different result than an investment in a portfolio that owned an equal number of each of the near 12 months’ worth of contracts. Generally speaking, when the natural gas futures market is in backwardation, the near month only portfolio would tend to have a higher total return than the 12 month contract portfolio. Conversely, if the natural gas futures market was in contango, the portfolio containing 12 months’ worth of contracts would tend to outperform the near month only portfolio. The chart below shows the annual results of owning a portfolio consisting of the near month contract and a portfolio containing the near 12 months’ worth of contracts. In addition, the chart shows the annual change in the spot price of natural gas. In this example, each month, the near month only portfolio would sell the near month contract at expiration and buy the next month out contract. The portfolio holding an equal number of the near 12 months’ worth of contracts would sell the near month contract at expiration and replace it with the contract that becomes the new twelfth month contract.

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*PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

HYPOTHETICAL PERFORMANCE RESULTS HAVE MANY INHERENT LIMITATIONS, SOME OF WHICH ARE DESCRIBED BELOW. NO REPRESENTATION IS BEING MADE THAT USNG WILL OR IS LIKELY TO ACHIEVE PROFITS OR LOSSES SIMILAR TO THOSE SHOWN. IN FACT, THERE ARE FREQUENTLY SHARP DIFFERENCES BETWEEN HYPOTHETICAL PERFORMANCE RESULTS AND THE ACTUAL RESULTS ACHIEVED BY ANY PARTICULAR TRADING PROGRAM.

ONE OF THE LIMITATIONS OF HYPOTHETICAL PERFORMANCE RESULTS IS THAT THEY ARE GENERALLY PREPARED WITH THE BENEFIT OF HINDSIGHT. IN ADDITION, HYPOTHETICAL TRADING DOES NOT INVOLVE FINANCIAL RISK, AND NO HYPOTHETICAL TRADING RECORD CAN COMPLETELY ACCOUNT FOR THE IMPACT OF FINANCIAL RISK IN ACTUAL TRADING.

FOR EXAMPLE, THE ABILITY TO WITHSTAND LOSSES OR TO ADHERE TO A PARTICULAR TRADING PROGRAM IN SPITE OF TRADING LOSSES ARE MATERIAL POINTS WHICH CAN ALSO ADVERSELY AFFECT ACTUAL TRADING RESULTS. THERE ARE NUMEROUS OTHER FACTORS RELATED TO THE MARKETS IN GENERAL OR TO THE IMPLEMENTATION OF ANY SPECIFIC TRADING PROGRAM WHICH CANNOT BE FULLY ACCOUNTED FOR IN THE PREPARATION OF HYPOTHETICAL PERFORMANCE RESULTS AND ALL OF WHICH CAN ADVERSELY AFFECT ACTUAL TRADING RESULTS.

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As seen in the chart above, there have been periods of both positive and negative annual total returns for both hypothetical portfolios over the last 10 years. In addition, there have been periods during which the near month only approach had higher returns, and periods where the 12 month approach had higher total returns. The above chart does not represent the performance history of USNG or any Related Public Fund.

Historically, the natural gas futures markets have experienced periods of contango and backwardation. Because natural gas demand is seasonal, it is possible for the price of Futures Contracts for delivery within one or two months to rapidly move from backwardation into contango and back again within a relatively short period of time of less than one year. While the investment objective of USNG is not to have the market price of its units match, dollar for dollar, changes in the spot price of natural gas, contango impacted the total return on an investment in USNG units during the year ended December 31, 2012 relative to a hypothetical direct investment in natural gas. For example, an investment in USNG units made on December 31, 2011 and held to December 31, 2012 decreased, based upon the changes in the NAV for USNG units on those days, by approximately 27.09%, while the spot price of natural gas for immediate delivery during the same period increased by approximately 12.00% (note: this comparison ignores the potential costs associated with physically owning and storing natural gas, which could be substantial). By comparison, an investment made in USNG units on December 31, 2010 and held to December 31, 2011 decreased, based upon the changes in the NAV for USNG units on those days, by approximately 46.08%, while the spot price of natural gas for immediate delivery during the same period decreased by approximately 32.15% (note: this comparison ignores the potential costs associated with physically owning and storing natural gas, which could be substantial).

Periods of contango or backwardation do not materially impact USNG’s investment objective of having the daily percentage changes in its per unit NAV track the daily percentage changes in the price of the Benchmark Futures Contract since the impact of backwardation and contango tend to equally impact the daily percentage changes in price of both USNG’s units and the Benchmark Futures Contract. It is impossible to predict with any degree of certainty whether backwardation or contango will occur in the future. It is likely that both conditions will occur during different periods and, because of the seasonal nature of natural gas demand, both may occur within a single year’s time.

Natural Gas Market. During the year ended December 31, 2012, natural gas prices in the United States were volatile and finished the period higher than the beginning of the year. Prices were impacted by several factors. The continued existence of a historic storage surplus weighed on prices during the first few months of the year, with prices reaching a low of $1.983 on April 12, 2012. However, reduced natural gas production and a reduction of the surplus contributed to an increase in natural gas prices since mid-April 2012. As of December 31, 2012, the amount of natural gas in storage had reached 3.517 billion cubic feet, which was approximately 8.3% and 1.3% above the five-year average and 2011 levels, respectively, but down from the peak surpluses that existed earlier in 2012.

By comparison, during the year ended December 31, 2011, natural gas prices in the United States were impacted by several factors. During the first quarter of 2011, the amount of natural gas in storage remained near the high of average levels as compared to 2010 levels. During the second and third quarter of 2011, the amount of natural gas in storage fell below 2010 levels to the approximate median of the maximum-minimum range of the previous five years. However, during the fourth quarter of 2011, the amount of natural gas in storage rose well above 2010 levels and the five-year average high storage level. As of December 31, 2011, the amount of natural gas in storage had reached 3.472 billion cubic feet, which was approximately 15% and 12% above the five-year average and 2010 levels, respectively. Although prices were volatile, they tended to trend along with the seasonal changes in natural gas storage levels during the first and second quarters but diverged from the seasonal trend during the third and fourth quarters. Warmer weather during most of the year contributed to the volatility in prices. In addition, increased natural gas production also contributed to a decline in natural gas prices during the year ended December 31, 2011, with prices reaching a low of $2.989 on December 31, 2011.

By comparison, during the year ended December 31, 2010, natural gas prices in the United States were impacted by several factors. At the beginning of 2010, the amount of natural gas in storage was at higher than average levels versus the previous five years and versus 2009 levels. During all of 2010, the seasonally adjusted inventory levels of stored natural gas remained above five-year averages and above 2009 levels. In addition, a combination of mild U.S. economic growth and increased natural gas production both contributed to a very significant decline in natural gas prices during most of 2010, with prices reaching a low of $3.292 near the end of October 2010 before finally ending the year with a price of $4.405.

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Natural Gas Price Movements in Comparison to Other Energy Commodities and Investment Categories. USCF believes that investors frequently measure the degree to which prices or total returns of one investment or asset class move up or down in value in concert with another investment or asset class. Statistically, such a measure is usually done by measuring the correlation of the price movements of the two different investments or asset classes over some period of time. The correlation is scaled between 1 and -1, where 1 indicates that the two investment options move up or down in price or value together, known as “positive correlation,” and -1 indicates that they move in completely opposite directions, known as “negative correlation.” A correlation of 0 would mean that the movements of the two are neither positively nor negatively correlated, known as “non-correlation.” That is, the investment options sometimes move up and down together and other times move in opposite directions.

For the ten year time period between 2003 and 2012, the table below compares the monthly movements of natural gas prices versus the monthly movements of the prices of several other energy commodities, such as crude oil, diesel-heating oil, and unleaded gasoline, as well as several major non-commodity investment asset classes, such as large cap U.S. equities, U.S. government bonds and global equities. It can be seen that over this particular time period, the movement of natural gas on a monthly basis was not strongly correlated with the movements of unleaded gasoline, crude oil, large cap U.S. equities, U.S. government bonds or global equities. Movements in natural gas had a positive, yet moderate, correlation to movements in diesel-heating oil.

PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

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The table below covers a more recent, but much shorter, range of dates than the above table. It can be seen that over this particular time period, the movement of natural gas on a monthly basis was negatively, although weakly, correlated with large-cap U.S. equities, global equities, crude oil, diesel-heating oil and unleaded gasoline. However, U.S. government bonds had a positive, yet weak, correlation over the shorter time period.

PAST PERFORMANCE IS NOT NECESSARILY INDICATIVE OF FUTURE RESULTS

Investors are cautioned that the historical price relationships between natural gas and various other energy commodities, as well as other investment asset classes, as measured by correlation may not be reliable predictors of future price movements and correlation results. The results pictured above would have been different if a different range of dates had been selected. USCF believes that natural gas has historically not demonstrated a strong correlation with equities or bonds over long periods of time. However, USCF also believes that in the future it is possible that natural gas could have long term correlation results that indicate prices of natural gas more closely track the movements of equities or bonds. In addition, USCF believes that, when measured over time periods shorter than ten years, there will always be some periods where the correlation of natural gas to equities and bonds will be either more strongly positively correlated or more strongly negatively correlated than the long term historical results suggest.

The correlations between natural gas, crude oil, diesel-heating oil and gasoline are relevant because USCF endeavors to invest USNG’s assets in natural gas Futures Contracts and Other Natural Gas-Related Investments so that daily changes in percentage terms in USNG’s per unit NAV correlate as closely as possible with daily changes in percentage terms in the price of the Benchmark Futures Contract. If certain other fuel-based commodity futures contracts do not closely correlate with the natural gas Futures Contract, then their use could lead to greater tracking error. As noted above, USCF also believes that the daily changes in percentage terms in the price of the Benchmark Oil Futures Contract will closely correlate with daily changes in percentage terms in the spot price of natural gas.

Critical Accounting Policies

Preparation of the financial statements and related disclosures in compliance with accounting principles generally accepted in the United States of America requires the application of appropriate accounting rules and guidance, as well as the use of estimates. USNG’s application of these policies involves judgments and actual results may differ from the estimates used.

USCF has evaluated the nature and types of estimates that it makes in preparing USNG’s financial statements and related disclosures and has determined that the valuation of its investments, which are not traded on a United States or internationally recognized futures exchange (such as forward contracts and over-the-counter contracts) involves a critical accounting policy. The values which are used by USNG for its Futures Contracts are provided by its commodity broker who uses market prices when available, while over-the-counter contracts are valued based on the present value of estimated future cash flows that would be received from or paid to a third party in settlement of these derivative contracts prior to their delivery date and valued on a daily basis. In addition, USNG estimates interest and dividend income on a daily basis using prevailing rates earned on its cash and cash equivalents. These estimates are adjusted to the actual amount received on a monthly basis and the difference, if any, is not considered material.

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Liquidity and Capital Resources

USNG has not made, and does not anticipate making, use of borrowings or other lines of credit to meet its obligations. USNG has met, and it is anticipated that USNG will continue to meet, its liquidity needs in the normal course of business from the proceeds of the sale of its investments, or from the investments in Treasuries, cash and/or cash equivalents that it intends to hold at all times. USNG’s liquidity needs include: redeeming units, providing margin deposits for its existing natural gas Futures Contracts or the purchase of additional natural gas Futures Contracts and posting collateral for its over-the-counter contracts and payment of its expenses, summarized below under “Contractual Obligations.”

USNG currently generates cash primarily from: (i) the sale of Creation Baskets and (ii) income earned on investments in Treasuries, cash and/or cash equivalents. USNG has allocated substantially all of its net assets to trading in Natural Gas Interests. USNG invests in Natural Gas Interests to the fullest extent possible without being leveraged or unable to satisfy its current or potential margin or collateral obligations with respect to its investments in Futures Contracts and Other Natural Gas-Related Investments. A significant portion of USNG’s NAV is held in cash and cash equivalents that are used as margin and as collateral for its trading in Natural Gas Interests. The balance of the assets is held in USNG’s account at the Custodian and in investments in Treasuries at the FCM. Income received from USNG’s investments in money market funds and Treasuries is paid to USNG. During the years ended December 31, 2012 and 2011, USNG’s expenses exceeded the income USNG earned and the cash earned from the sale of Creation Baskets and the redemption of Redemption Baskets. During the years ended December 31, 2012 and 2011, USNG was forced to use other assets to pay expenses, which could cause a drop in USNG’s NAV over time. To the extent expenses exceed income, USNG’s NAV will be negatively impacted.

USNG’s investments in Natural Gas Interests may be subject to periods of illiquidity because of market conditions, regulatory considerations and other reasons. For example, most commodity exchanges limit the fluctuations in futures contracts prices during a single day by regulations referred to as “daily limits.” During a single day, no trades may be executed at prices beyond the daily limit. Once the price of a futures contract has increased or decreased by an amount equal to the daily limit, positions in the contracts can neither be taken nor liquidated unless the traders are willing to effect trades at or within the specified daily limit. In addition, USNG’s over-the-counter contracts have very limited liquidity since they are negotiated agreements that are not transferable by USNG except with the consent of its counterparty, and even if consent were granted, there may not be an available transferee. Such market conditions or contractual limits could prevent USNG from promptly liquidating its positions in Natural Gas Interests. During the year ended December 31, 2012, USNG was not forced to purchase or liquidate any of its positions while daily limits were in effect; however, USNG cannot predict whether such an event may occur in the future.

Since the initial offering of units, USNG has been responsible for expenses relating to: (i) management fees, (ii) brokerage fees and commissions and fees associated with its over-the-counter transactions, (iii) licensing fees for the use of intellectual property, (iv) ongoing registration expenses in connection with offers and sales of its units subsequent to the initial offering, (v) other expenses, including tax reporting costs, (vi) fees and expenses of the independent directors of USCF and (vii) other extraordinary expenses not in the ordinary course of business, while USCF has been responsible for expenses relating to the fees of USNG’s Marketing Agent, Administrator and Custodian and registration expenses relating to the initial offering of units. If USCF and USNG are unsuccessful in raising sufficient funds to cover these respective expenses or in locating any other source of funding, USNG will terminate and investors may lose all or part of their investment.

Market Risk

Trading in Futures Contracts and Other Natural Gas-Related Investments, such as forwards, involves USNG entering into contractual commitments to purchase or sell natural gas at a specified date in the future. The aggregate market value of the contracts will significantly exceed USNG’s future cash requirements since USNG intends to close out its open positions prior to settlement. As a result, USNG is generally only subject to the risk of loss arising from the change in value of the contracts. USNG considers the “fair value” of its derivative instruments to be the unrealized gain or loss on the contracts. The market risk associated with USNG’s commitments to purchase natural gas is limited to the aggregate market value of the contracts held. However, should USNG enter into a contractual commitment to sell natural gas, it would be required to make delivery of the natural gas at the contract price, repurchase the contract at prevailing prices or settle in cash. Since there are no limits on the future price of natural gas, the market risk to USNG could be unlimited.

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USNG’s exposure to market risk depends on a number of factors, including the markets for natural gas, the volatility of interest rates and foreign exchange rates, the liquidity of the Futures Contracts and Other Natural Gas-Related Investments markets and the relationships among the contracts held by USNG. Drastic market occurrences could ultimately lead to the loss of all or substantially all of an investor’s capital.

Credit Risk

When USNG enters into Futures Contracts and Other Natural Gas-Related Investments, it is exposed to the credit risk that the counterparty will not be able to meet its obligations. The counterparty for the Futures Contracts traded on the NYMEX and on most other futures exchanges is the clearinghouse associated with the particular exchange. In general, in addition to margin required to be posted by the clearinghouse in connection with cleared trades, clearinghouses are backed by their members who may be required to share in the financial burden resulting from the nonperformance of one of their members and, therefore, this additional member support should significantly reduce credit risk. Some foreign exchanges are not backed by their clearinghouse members but may be backed by a consortium of banks or other financial institutions. There can be no assurance that any counterparty, clearinghouse, or their members or their financial backers will satisfy their obligations to USNG in such circumstances.

During the year ended December 31, 2012, USNG entered into fully-collateralized over-the-counter transactions with two counterparties, JPMorgan Chase Bank, NA (“JPMorgan”) and Deutsche Bank AG (“Deutsche Bank”). Unlike most of the exchange-traded Futures Contracts, cleared swaps or exchange-traded options on such futures, each party to an over-the-counter contract bears the credit risk that the other party may not be able to perform its obligations under its contract.

USCF attempts to manage the credit risk of USNG by following various trading limitations and policies. In particular, USNG generally posts margin and/or holds liquid assets that are approximately equal to the market value of its obligations to counterparties under the Futures Contracts and Other Natural Gas-Related Investments it holds. USCF has implemented procedures that include, but are not limited to, executing and clearing trades only with creditworthy parties and/or requiring the posting of collateral or margin by such parties for the benefit of USNG to limit its credit exposure. UBS Securities, USNG’s commodity broker, or any other broker that may be retained by USNG in the future, when acting as USNG’s FCM in accepting orders to purchase or sell Futures Contracts on United States exchanges, is required by CFTC regulations to separately account for and segregate as belonging to USNG, all assets of USNG relating to domestic Futures Contracts trading. These FCMs are not allowed to commingle USNG’s assets with their other assets. In addition, the CFTC requires commodity brokers to hold in a secure account USNG’s assets related to foreign Futures Contracts trading and, in some cases, to cleared swaps executed through the FCM. Similarly, under its current over-the-counter agreements, USNG requires that collateral it posts or receives be posted with the Custodian, and under agreements among the Custodian, USNG and its counterparties, such collateral is segregated.

See “Item 7A. Quantitative and Qualitative Disclosures About Market Risk” in this annual report on Form 10-K for a discussion of over-the-counter contracts.

As of December 31, 2012, USNG held cash deposits and investments in Treasuries and money market funds in the amount of $1,245,314,221 with the Custodian and FCM. Some or all of these amounts may be subject to loss should the Custodian and/or FCM cease operations.

Off Balance Sheet Financing

As of December 31, 2012, USNG had no loan guarantee, credit support or other off-balance sheet arrangements of any kind other than agreements entered into in the normal course of business, which may include indemnification provisions relating to certain risks that service providers undertake in performing services which are in the best interests of USNG. While USNG’s exposure under these indemnification provisions cannot be estimated, they are not expected to have a material impact on USNG’s financial position.

European Sovereign Debt

USNG had no direct exposure to European sovereign debt as of December 31, 2012 and has no direct exposure to European sovereign debt as of the filing of this annual report on Form 10-K.

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Redemption Basket Obligation

In order to meet its investment objective and pay its contractual obligations described below, USNG requires liquidity to redeem units, which redemptions must be in blocks of 100,000 units called “Redemption Baskets.” USNG has to date satisfied this obligation by paying from the cash or cash equivalents it holds or through the sale of its Treasuries in an amount proportionate to the number of units being redeemed.

Contractual Obligations

USNG’s primary contractual obligations are with USCF. In return for its services, USCF is entitled to a management fee calculated daily and paid monthly as a fixed percentage of USNG’s NAV, currently 0.60% for a NAV of $1 billion or less, and thereafter at a rate of 0.50% for a NAV above $1 billion.

USCF agreed to pay the start-up costs associated with the formation of USNG, primarily its legal, accounting and other costs in connection with USCF’s registration with the CFTC as a CPO and the registration and listing of USNG and its units with the SEC, FINRA and NYSE Arca (formerly, AMEX), respectively. However, since USNG’s initial offering of units, offering costs incurred in connection with registering and listing additional units of USNG have been directly borne on an ongoing basis by USNG, and not by USCF.

USCF pays the fees of the Marketing Agent and the fees of the Custodian and Transfer Agent, BBH&Co., as well as BBH&Co.’s fees for performing administrative services, including those in connection with the preparation of USNG’s financial statements and its SEC, NFA and CFTC reports. USCF and USNG have also entered into a licensing agreement with the NYMEX pursuant to which USNG and the Related Public Funds, other than USBO, USCI, CPER, USAG and USMI, pay a licensing fee to the NYMEX. USNG also pays the fees and expenses associated with its tax accounting and reporting requirements.

In addition to USCF’s management fee, USNG pays its brokerage fees (including fees to a FCM), over-the-counter dealer spreads, any licensing fees for the use of intellectual property, and, subsequent to the initial offering, registration and other fees paid to the SEC, FINRA, or other regulatory agencies in connection with the offer and sale of units, as well as legal, printing, accounting and other expenses associated therewith, and extraordinary expenses. The latter are expenses not incurred in the ordinary course of USNG’s business, including expenses relating to the indemnification of any person against liabilities and obligations to the extent permitted by law and under the LP Agreement, the bringing or defending of actions in law or in equity or otherwise conducting litigation and incurring legal expenses and the settlement of claims and litigation. Commission payments to a FCM are on a contract-by-contract, or round turn, basis. USNG also pays a portion of the fees and expenses of the independent directors of USCF. See Note 3 to the Notes to Financial Statements in Item 8 of this annual report on Form 10-K.

The parties cannot anticipate the amount of payments that will be required under these arrangements for future periods, as USNG’s per unit NAVs and trading levels to meet its investment objective will not be known until a future date. These agreements are effective for a specific term agreed upon by the parties with an option to renew, or, in some cases, are in effect for the duration of USNG’s existence. Either party may terminate these agreements earlier for certain reasons described in the agreements.

As of December 31, 2012, USNG’s portfolio consisted of 17,891 Natural Gas NG Futures Contracts traded on the NYMEX, 17,952 Natural Gas NN Financially Settled Futures Contracts traded on the NYMEX, 30,192 cleared swaps traded on the ICE Futures and total return swaps with an aggregate market value of $(3,470,939). For a list of USNG’s current holdings, please see USNG’s website at www.unitedstatesnaturalgasfund.com.

Item 7A. Quantitative and Qualitative Disclosures About Market Risk.

Over-the-Counter Derivatives (Including Spreads and Straddles)

At December 31, 2012, USNG maintained fully-collateralized over-the-counter swap transactions (“OTC Contracts”) with two counterparties, JPMorgan and Deutsche Bank. Unlike most exchange-traded Futures Contracts, cleared swaps or exchange-traded options on such futures, each party to an OTC Contract bears the credit risk that the other party may not be able to perform its obligations under its contract.

Swap transactions, like other financial transactions, involve a variety of significant risks. The specific risks presented by a particular swap transaction necessarily depend upon the terms and circumstances of the transaction. In general, however, all swap transactions involve some combination of market risk, credit risk, counterparty credit risk, funding risk, liquidity risk and operational risk.

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Highly customized swap transactions in particular may increase liquidity risk, which may result in a suspension of redemptions. Highly leveraged transactions may experience substantial gains or losses in value as a result of relatively small changes in the value or level of an underlying or related market factor.

In evaluating the risks and contractual obligations associated with a particular swap transaction, it is important to consider that a swap transaction may be modified or terminated only by mutual consent of the original parties and subject to agreement on individually negotiated terms. Therefore, it may not be possible for USCF to modify, terminate or offset USNG’s obligations or its exposure to the risks associated with a transaction prior to its scheduled termination date.

To reduce the credit risk that arises in connection with such contracts, USNG will generally enter into an agreement with each counterparty based on the Master Agreement published by ISDA that provides for the netting of its overall exposure to its counterparty, if the counterparty is unable to meet its obligations to USNG due to the occurrence of a specified event, such as the insolvency of the counterparty.

USCF assesses or reviews, as appropriate, the creditworthiness of each potential or existing counterparty to an OTC Contract pursuant to guidelines approved by USCF’s Board. Furthermore, USCF on behalf of USNG only enters into OTC Contracts with counterparties who are, or are affiliates of, (a) banks regulated by a United States federal bank regulator, (b) broker-dealers regulated by the SEC, (c) insurance companies domiciled in the United States, or (d) producers, users or traders of energy, whether or not regulated by the CFTC. Any entity acting as a counterparty shall be regulated in either the United States or the United Kingdom unless otherwise approved by the Board after consultation with its legal counsel. Existing counterparties are also reviewed periodically by USCF. USNG will also require that the counterparty be highly rated and/or provide collateral or other credit support. Even if collateral is used to reduce counterparty credit risk, sudden changes in the value of OTC transactions may leave a party open to financial risk due to a counterparty default since the collateral held may not cover a party’s exposure on the transaction in such situations.

Both the Board and its audit committee review statistics and data pertaining to each of USNG’s over-the-counter counterparties. Reports are provided verbally and in writing by USCF’s management at least quarterly and more frequently when deemed necessary. Data reviewed includes, but is not limited to, short-term and long-term credit ratings by Moody’s Investor Service, Inc., Standard & Poor’s Financial Services LLC and Fitch Ratings; changes in market capitalization and stock prices over the last five years; numerous financial ratios including capital and leverage ratios; and credit default swap yields and spreads. Additionally, members of USCF’s Board, audit committee and management team may note general economic or company specific news that necessitates a review of a counterparty’s creditworthiness outside of the regular review cycle. Board members and audit committee members may conduct their own analysis and contact USCF’s management team at their discretion to request further information or action. Board members are apprised of open positions as well as changes to positions and counterparties utilized by USNG on an ongoing basis. Significant changes to USNG’s over-the-counter contract holdings are reported to the Board in a timely manner.

In general, valuing OTC derivatives is less certain than valuing actively traded financial instruments such as exchange-traded futures contracts and securities or cleared swaps because the price and terms on which such OTC derivatives are entered into or can be terminated are individually negotiated, and those prices and terms may not reflect the best price or terms available from other sources. In addition, while market makers and dealers generally quote indicative prices or terms for entering into or terminating OTC Contracts, they typically are not contractually obligated to do so, particularly if they are not a party to the transaction. As a result, it may be difficult to obtain an independent value for an outstanding OTC derivatives transaction.

During the year ended December 31, 2012, USNG employed hedging methods such as those described above to the extent it invested in fully-collateralized over-the-counter swap transactions designed to track percentage changes in the price of the Benchmark Futures Contract. During the year ended December 31, 2012, USNG was exposed to counterparty risk on its fully-collateralized over-the-counter swap transactions with two counterparties, JPMorgan and Deutsche Bank.

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The counterparty credit ratings for the exposure on over-the-counter swap transactions to which USNG was a party that would be owed to USNG due to a default or early termination by USNG’s counterparties as of December 31, 2012 and 2011 were:

The aggregate notional amount of USNG’s over-the-counter derivative transactions, all of which consisted of total return swaps, decreased to $186,936,060 at December 31, 2012, as compared to $261,626,092 at December 31, 2011. The aggregate notional amount of these derivative transactions, which is not included in the Schedule of Investments, is indicative of USNG’s activities in derivative transactions, but is not an indicator of the level of credit risk associated with these transactions. The aggregate notional amount of USNG’s over-the-counter swap transactions represented 15.00% of USNG’s total assets as of December 31, 2012.

USNG maintains, in conjunction with its counterparties, collateral in the form of both cash and investments in Treasuries, depending on the specific arrangements with each counterparty. USNG is required to post an independent amount based on a percentage of the initial notional amount of each position at the inception of each over-the-counter contract. In addition, between reset periods, USNG posts collateral for the benefit of its counterparties that approximately corresponds to any unrealized loss that would be realized by USNG if the over-the-counter contract were closed on any given valuation date. Likewise, USNG’s counterparties post collateral for USNG’s benefit that approximately corresponds to any unrealized gain that would be realized by USNG if the over-the-counter contract were to be closed on any given valuation date. At each reset date, USNG will make or receive settlement payments to or from its counterparties, and collateral posted by or for USNG will be returned to the appropriate party to offset the settlement payment made. Collateral is held by an independent third party and governed by tri-party agreements between USNG, the Custodian and each counterparty.

At December 31, 2012, USNG’s counterparties posted $1,700,020 in cash and $0 in securities as collateral with the Custodian, as compared to $990,210 in cash and $0 in securities at December 31, 2011. Under these over-the-counter swap agreements, USNG posted collateral with respect to its obligations of $15,511,111 in cash and $16,454,930 in securities, such as Treasuries, at December 31, 2012, as compared with $27,143,621 in cash and $26,431,111 in securities at December 31, 2011.

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Item 8.    Financial Statements and Supplementary Data.

United States Natural Gas Fund, LP

Index to Financial Statements

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Management’s Annual Report on Internal Control Over Financial Reporting.

USCF assessed the effectiveness of USNG’s internal control over financial reporting as of December 31, 2012. In making this assessment, it used the criteria set forth by the Committee of Sponsoring Organizations of the Treadway Commission in Internal Control Integrated Framework. Based on the assessment, USCF believes that, as of December 31, 2012, USNG’s internal control over financial reporting is effective.

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Attestation Report of Registered Public Accounting Firm.

Report of Independent Registered Public Accounting Firm

Auditors’ Report on Internal Control over Financial Reporting

To the Partners of

United States Natural Gas Fund, LP

We have audited the internal control over financial reporting of United States Natural Gas Fund, LP (the “Fund”) as of December 31, 2012, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission. The Fund’s management is responsible for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Annual Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Fund’s internal control over financial reporting based on our audit.

We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audit also included performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

An entity’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with accounting principles generally accepted in the United States of America. An entity’s internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the entity; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the entity are being made only in accordance with authorizations of management and directors of the entity; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the entity’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of the effectiveness to future periods are subject to the risk that the controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

In our opinion, the Fund maintained, in all material respects, effective internal control over financial reporting as of December 31, 2012, based on the criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission.

We have also audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the financial statements as of and for the year ended December 31, 2012, of the Fund and our report dated February 27, 2013 expressed an unqualified opinion on those financial statements.

/s/ Spicer Jeffries LLP

Greenwood Village, Colorado

February 27, 2013

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Report of Independent Registered Public Accounting Firm

To the Partners of

United States Natural Gas Fund, LP

We have audited the accompanying statements of financial condition of United States Natural Gas Fund, LP (the “Fund”) as of December 31, 2012 and 2011, including the schedule of investments as of December 31, 2012 and 2011, and the related statements of operations, changes in partners’ capital and cash flows for the years ended December 31, 2012, 2011 and 2010. These financial statements are the responsibility of the Fund’s management. Our responsibility is to express an opinion on these financial statements based on our audits.

We conducted our audits in accordance with standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of United States Natural Gas Fund, LP as of December 31, 2012 and 2011, and the results of its operations and its cash flows for the years ended December 31, 2012, 2011 and 2010, in conformity with accounting principles generally accepted in the United States of America.

We also have audited, in accordance with standards of the Public Company Accounting Oversight Board (United States), the Fund’s internal control over financial reporting as of December 31, 2012, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 27, 2013 expressed an unqualified opinion on the Fund’s internal control over financial reporting.

/s/ Spicer Jeffries LLP

Greenwood Village, Colorado

February 27, 2013

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United States Natural Gas Fund, LP

Statements of Financial Condition

At December 31, 2012 and 2011

* On February 21, 2012, there was a 4-for-1 reverse unit split. Historical units outstanding, net asset value per unit and market value per unit have been adjusted to reflect the 4-for-1 reverse unit split on a retroactive basis.

See accompanying notes to financial statements.

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United States Natural Gas Fund, LP

Schedule of Investments

At December 31, 2012

Open Over-the-Counter Total Return Swap Contracts

* Security or partial security segregated as collateral for open over-the-counter total return swap contracts.

** The aggregate notional amount of USNG’s over-the-counter swap transactions represented 15.00% of USNG’s total assets as of December 31, 2012.

See accompanying notes to financial statements.

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United States Natural Gas Fund, LP

Schedule of Investments

At December 31, 2011