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Condensed Schedule of Investments	Mar. 31, 2018 USD ($) Contracts
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ (356,400)
Open Futures Contracts - Long [Member] | United States [Member]
Notional Amount	$ 351,683,550	[1]
Number of Contracts | Contracts	24,855	[1]
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ (356,400)	[1]
% of Partners' Capital	(0.10%)	[1]
Open Futures Contracts - Long [Member] | United States [Member] | NYMEX Natural Gas Futures NG May 2018 contracts, expiring May 2018 [Member]
Notional Amount	$ 241,558,550
Number of Contracts | Contracts	8,855
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ 448,600
% of Partners' Capital	0.13%
Open Futures Contracts - Long [Member] | United States [Member] | ICE Natural Gas Futures LD1 H May 2018 contracts, expiring May 2018 [Member]
Notional Amount	$ 110,125,000
Number of Contracts | Contracts	16,000
Value/ Unrealized Gain (Loss) on Open Commodity Contracts	$ (805,000)
% of Partners' Capital	(0.23%)
Cash Equivalents [Member]
Market Value	$ 344,160,351
% of Partners' Capital	97.96%
Cash Equivalents [Member] | United States Treasury Obligations [Member]
Market Value	$ 319,160,351
% of Partners' Capital	90.84%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.22%, 4/12/2018 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,990,719
% of Partners' Capital	7.11%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.23%, 4/19/2018 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,984,781
% of Partners' Capital	7.11%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.25%, 4/26/2018 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,978,472
% of Partners' Capital	7.11%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.27%, 5/03/2018 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,983,200
% of Partners' Capital	4.27%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.32%, 5/10/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,971,617
% of Partners' Capital	5.68%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.37%, 5/17/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,965,308
% of Partners' Capital	5.68%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.43%, 5/24/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,958,336
% of Partners' Capital	5.68%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.43%, 5/31/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,952,667
% of Partners' Capital	5.68%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.45%, 6/07/2018 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,946,400
% of Partners' Capital	5.68%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.46%, 6/14/2018 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,925,743
% of Partners' Capital	7.10%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.49%, 6/21/2018 [Member]
Principal Amount	$ 30,000,000
Market Value	$ 29,900,100
% of Partners' Capital	8.51%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.50%, 6/28/2018 [Member]
Principal Amount	$ 30,000,000
Market Value	$ 29,890,733
% of Partners' Capital	8.51%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.56%, 7/05/2018 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,959,097
% of Partners' Capital	2.84%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.56%, 7/12/2018 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,956,083
% of Partners' Capital	2.83%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.77%, 8/16/2018 [Member]
Principal Amount	$ 5,000,000
Market Value	$ 4,966,606
% of Partners' Capital	1.41%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.82%, 8/23/2018 [Member]
Principal Amount	$ 5,000,000
Market Value	$ 4,964,000
% of Partners' Capital	1.41%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.85%, 9/06/2018 [Member]
Principal Amount	$ 5,000,000
Market Value	$ 4,959,842
% of Partners' Capital	1.41%
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.90%, 9/27/2018 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,906,647
% of Partners' Capital	2.82%
Cash Equivalents [Member] | Money Market Funds [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member]
Principal Amount	$ 25,000,000
Market Value	$ 25,000,000
% of Partners' Capital	7.12%
[1] Collateral amounted to $64,518,650 on open futures contracts.

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