Statements of Cash Flows (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net Income (Loss)	$ 192,790,526	$ 40,765,629
Adjustments to reconcile net income (loss) to net cash provided by (used for) operating activities:
Cost of securities purchased	(717,469,849)	(2,267,204,250)
Proceeds from securities sold and matured	893,450,782	1,752,923,526
Cost of affiliated investments purchased	(914,538,133)	(986,200,691)
Proceeds from affiliated investments sold	990,145,147	935,388,213
Net accretion of discount on United States Treasury Obligations	(9,157,734)	(7,586,315)
Net realized (gain) loss on United States Treasury Obligations and Affiliated Investments	20,868	(4,429)
Net change in unrealized (gain) loss on United States Treasury Obligations, Affiliated Investments and Commodity Futures Contracts	(34,953,572)	37,897,790
Change in operating assets and liabilities:
Dividends from affiliates	89,147	(67,680)
Variation margin - Commodity Futures Contracts	(2,949,814)	(9,825,283)
LME Commodity Futures Contracts	(25,505,506)	2,110,369
Management fees	(148,480)	351,797
Brokerage commissions and fees	4,695	78,107
Other receivables	17,077
Net cash provided by (used for) operating activities	371,795,154	(501,373,217)
Cash flows from financing activities:
Proceeds from purchases of Shares	48,178,241	699,144,463
Redemption of Shares	(401,013,118)	(203,710,810)
Decrease in payable for amount due to custodian, net	(18,960,277)
Net cash provided by (used for) financing activities	(371,795,154)	495,433,653
Net change in cash		(5,939,564)
Cash at beginning of period		5,939,564
Cash at end of period	0	0
Supplemental disclosure of cash flow information
Cash paid for interest	$ 214,655	$ 6,778