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FAIR VALUE OF FINANCIAL INSTRUMENTS - Fair Value of Derivative Instruments (Details) - USD ($)
Jun. 30, 2020
Dec. 31, 2019
Commodity Contracts | Assets | Futures    
Derivatives, Fair Value [Line Items]    
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net $ 66,376,630 $ 3,602,591