Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net Income (Loss)	$ (13,241,667)	$ (620,141)
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Cost of securities purchased	(291,329,492)	(506,491,544)
Proceeds from securities sold and matured	336,945,573	393,979,217
Cost of affiliated investments purchased	(358,557,089)	(193,623,649)
Proceeds from affiliated investments sold	355,462,299	217,719,212
Net accretion of discount on United States Treasury Obligations	(2,204,900)	(2,077,793)
Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments	1,430	745
Net change in unrealized (gain) loss on United States Treasury Obligations and Affiliated Investments	(51,086)	(196,752)
Change in operating assets and liabilities:
Variation margin - Commodity Futures Contracts	2,800,931	(3,475,596)
Dividends from affiliates	(9,912)	(5,090)
Management fees	(59,383)	95,022
Brokerage commissions and fees	78	(10,672)
Net cash provided by (used for) operating activities	29,756,782	(94,707,041)
Cash flows from financing activities:
Proceeds from purchases of Shares	16,951,145	115,107,662
Redemption of Shares	(43,494,213)	(22,661,544)
Increase (decrease) in payable for amount due to custodian, net	(3,213,714)
Net cash provided by (used for) financing activities	(29,756,782)	92,446,118
Net change in cash		(2,260,923)
Cash at beginning of period		2,260,923
Cash at end of period	0	0
Supplemental disclosure of cash flow information
Cash paid for interest	$ 5,250	$ 3,838