Note 4 - Fair Value Measurements - Assets and Liabilities Measured at Fair Value - Hashdex Bitcoin Futures ETF (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Cash Equivalents	$ 388,000,477	$ 152,949,199
Total	396,207,858	166,364,500
Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	29,152
Hashdex Bitcoin Futures ETF [Member]
Cash Equivalents	701,969
Total	731,121
Hashdex Bitcoin Futures ETF [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	29,152
Fair Value, Inputs, Level 1 [Member]
Cash Equivalents	388,000,477	152,949,199
Total	396,207,858	166,364,500
Fair Value, Inputs, Level 1 [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	29,152
Fair Value, Inputs, Level 1 [Member] | Hashdex Bitcoin Futures ETF [Member]
Cash Equivalents	701,969
Total	731,121
Fair Value, Inputs, Level 1 [Member] | Hashdex Bitcoin Futures ETF [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	29,152
Fair Value, Inputs, Level 2 [Member]
Cash Equivalents	0	0
Total	0	0
Fair Value, Inputs, Level 2 [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	0
Fair Value, Inputs, Level 2 [Member] | Hashdex Bitcoin Futures ETF [Member]
Cash Equivalents	0
Total	0
Fair Value, Inputs, Level 2 [Member] | Hashdex Bitcoin Futures ETF [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	0
Fair Value, Inputs, Level 3 [Member]
Cash Equivalents	0	0
Total	0	$ 0
Fair Value, Inputs, Level 3 [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	0
Fair Value, Inputs, Level 3 [Member] | Hashdex Bitcoin Futures ETF [Member]
Cash Equivalents	0
Total	0
Fair Value, Inputs, Level 3 [Member] | Hashdex Bitcoin Futures ETF [Member] | Bitcoin Futures Contracts [Member]
Commodity and Cryptocurrency Futures Contracts	$ 0