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Condensed Schedule of Investments	Sep. 30, 2018 USD ($)
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ 20,601,460
Open Futures Contracts - Long [Member] | United States [Member]
Notional Amount	$ 284,830,860	[1]
Number of Contracts	14,654	[1]
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ 20,601,460	[1]
% of Partners' Capital	6.74%	[1]
Open Futures Contracts - Long [Member] | United States [Member] | ICE Natural Gas Futures LD1 H November 2018 contracts, expiring November 2018
Notional Amount	$ 41,852,500
Number of Contracts	6,000
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ 3,267,500
% of Partners' Capital	1.07%
Open Futures Contracts - Long [Member] | United States [Member] | NYMEX Natural Gas Futures NG November 2018 contracts, expiring November 2018
Notional Amount	$ 242,978,360
Number of Contracts	8,654
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ 17,333,960
% of Partners' Capital	5.67%
Cash Equivalents [Member]
Market Value	$ 300,663,124
% of Partners' Capital	98.43%
Cash Equivalents [Member] | United States Treasury Obligations [Member]
Market Value	$ 293,463,124
% of Partners' Capital	96.07%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.97%, 10/18/2018 [Member]
Principal Amount	$ 5,000,000
Market Value	$ 4,995,396
% of Partners' Capital	1.63%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.00%, 10/25/2018 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,986,800
% of Partners' Capital	3.27%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.00%, 11/01/2018 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,982,950
% of Partners' Capital	3.27%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.03%, 11/08/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,957,672
% of Partners' Capital	6.53%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.05%, 11/15/2018 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,961,938
% of Partners' Capital	4.90%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.07%, 11/23/2018 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,954,729
% of Partners' Capital	4.90%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.05%, 11/29/2018 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,950,219
% of Partners' Capital	4.89%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.09%, 12/06/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,924,100
% of Partners' Capital	6.52%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.06%, 12/13/2018 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,896,583
% of Partners' Capital	8.15%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.09%, 12/20/2018 [Member]
Principal Amount	$ 30,000,000
Market Value	$ 29,862,000
% of Partners' Capital	9.78%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.07%, 12/27/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,900,917
% of Partners' Capital	6.51%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.10%, 1/03/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,945,819
% of Partners' Capital	3.26%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.10%, 1/10/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,941,644
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.13%, 1/17/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,936,700
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.15%, 1/24/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,932,118
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.18%, 1/31/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,926,969
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.20%, 2/07/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,922,063
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.20%, 2/21/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,913,406
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.38%, 3/07/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,897,296
% of Partners' Capital	3.24%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.28%, 3/14/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,897,272
% of Partners' Capital	3.24%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.33%, 3/21/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,890,750
% of Partners' Capital	3.24%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.34%, 3/28/2019 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,885,783
% of Partners' Capital	3.24%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member]
Market Value	$ 7,200,000
% of Partners' Capital	2.36%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member]
Principal Amount	$ 6,000,000
Market Value	$ 6,000,000
% of Partners' Capital	1.97%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Morgan Stanley Institutional Liquidity Funds - Government Portfolio [Member]
Principal Amount	$ 1,200,000
Market Value	$ 1,200,000
% of Partners' Capital	0.39%
[1] Collateral amounted to $19,957,672 on open futures contracts.

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