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CONTRACTS AND AGREEMENTS - Brokerage and Futures Commissions (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Total commissions accrued to brokers	$ 264	$ 467	$ 636	$ 785
Total commissions as annualized percentage of average total net assets	0.03%	0.02%	0.03%	0.02%
Rebalancing Investments Transaction [Member]
Total commissions accrued to brokers			$ 538	$ 565
Total commissions as annualized percentage of average total net assets	84.59%	71.97%	84.59%	71.97%
Creation And Redemption Activity [Member]
Total commissions accrued to brokers			$ 98	$ 220
Total commissions as annualized percentage of average total net assets	15.41%	28.03%	15.41%	28.03%

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- Definition

Percentage of Average Daily Net Assets

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- Definition

The amount of expense during the period for floor brokerage fees paid to other broker-dealers to execute trades on their behalf, stock exchange fees, order flow fees, and clearance fees.

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