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Condensed Schedule of Investments	Jun. 30, 2019 USD ($)
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ (5,081,810)
Open Futures Contracts - Long [Member] | United States [Member] | NYMEX Natural Gas Futures Ng August 2019 Contracts Expiring July 2019 [Member]
Notional Amount	$ 330,002,050	[1]
Number of Contracts	14,078	[1]
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ (5,081,810)	[1]
% of Partners' Capital	(1.56%)	[1]
Cash Equivalents [Member]
Market Value	$ 308,568,941
% of Partners' Capital	94.96%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 7/05/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,997,294
% of Partners' Capital	3.08%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 7/11/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,993,187
% of Partners' Capital	3.08%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 7/18/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,988,478
% of Partners' Capital	3.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 7/25/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,983,733
% of Partners' Capital	3.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 8/01/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,978,903
% of Partners' Capital	3.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 8/08/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,974,350
% of Partners' Capital	3.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 8/15/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,969,500
% of Partners' Capital	3.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.47%, 8/22/2019 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,947,242
% of Partners' Capital	4.60%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 8/29/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,959,847
% of Partners' Capital	3.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 9/05/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,955,083
% of Partners' Capital	3.06%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.48%, 9/12/2019 [Member]
Principal Amount	$ 5,000,000
Market Value	$ 4,975,210
% of Partners' Capital	1.53%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.46%, 9/19/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,946,000
% of Partners' Capital	3.06%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 9/26/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,942,363
% of Partners' Capital	3.06%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.40%, 10/03/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,937,986
% of Partners' Capital	3.06%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.41%, 10/10/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,933,087
% of Partners' Capital	3.06%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.40%, 10/24/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,924,292
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.37%, 10/31/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,920,700
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.40%, 11/07/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,914,896
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.38%, 11/14/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,911,034
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.37%, 11/21/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,907,050
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.33%, 11/29/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,903,318
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.20%, 12/05/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,904,928
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.16%, 12/12/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,902,511
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.15%, 12/19/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,899,063
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.07%, 12/26/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,898,886
% of Partners' Capital	3.05%
Cash Equivalents [Member] | United States [Member]
Market Value	$ 248,568,941
% of Partners' Capital	76.51%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member]
Market Value	$ 60,000,000
% of Partners' Capital	18.45%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Fidelity Investments Money Market Funds Government Portfolio [Member]
Principal Amount	$ 20,000,000
Market Value	$ 20,000,000
% of Partners' Capital	6.15%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member]
Principal Amount	$ 20,000,000
Market Value	$ 20,000,000
% of Partners' Capital	6.15%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Morgan Stanley Institutional Liquidity Funds - Government Portfolio [Member]
Principal Amount	$ 20,000,000
Market Value	$ 20,000,000
% of Partners' Capital	6.15%
[1] Collateral amounted to $64,862,897 on open futures contracts.

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