Statements of Financial Condition (Unaudited) - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Assets
United States Treasury Obligations, at value (cost $537,558,967 and $846,190,082, respectively)	$ 537,597,215	$ 846,158,812
Affiliated Investments, at value and cost	2,039,940	3,786,312
Total Investments, at value (cost $539,598,907 and $849,976,394, respectively)	539,637,155	849,945,124
Receivable for:
Variation margin	311,025
Dividends from affiliates	15,722	16,819
Total assets	539,963,902	849,961,943
Payable for:
Variation margin		3,514,750
Due to custodian	1,000	1,000
Management fee	353,466	532,758
Brokerage commissions and fees	4,696	4,196
Total liabilities	359,162	4,052,704
Commitments and Contingencies (Note 9)
Equity
Shareholder's equity—General Shares	990	1,057
Shareholders' equity—Shares	539,603,750	845,908,182
Total shareholders' equity	539,604,740	845,909,239
Total liabilities and equity	$ 539,963,902	$ 849,961,943
General Shares outstanding	40	40
Shares outstanding	21,800,000	32,000,000
Net asset value per share	$ 24.75	$ 26.43
Market value per share	$ 24.76	$ 26.45