Note 2 - Significant Accounting Policies - Activity in Bitcoin (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Jun. 30, 2024 USD ($)
Beginning balance	252,011	0	0
Beginning balance, average cost	$ 13,984,500,952	$ 0	$ 0
Beginning balance, fair value	$ 17,791,246,945	0	$ 0
Bitcoin purchased	55,736		307,752
Bitcoin purchased, average cost	$ 3,807,994,861		$ 17,792,752,818
Bitcoin purchased, fair value	$ 3,807,994,861		$ 17,792,752,818
Bitcoin sold for the redemption of shares	(640)		(640)
Bitcoin sold for the redemption of shares, average cost	$ (36,148,475)		$ (36,148,475)
Bitcoin sold for the redemption of shares, fair value	(37,021,363)		(37,021,363)
Bitcoin sold for the redemption of shares, realized gain (loss)	$ 872,888		$ 872,888
Bitcoin sold to pay expenses	(128)		(133)
Bitcoin sold to pay expenses, average cost	$ (7,281,748)		$ (7,538,753)
Bitcoin sold to pay expenses, fair value	(8,636,353)		(8,993,883)
Bitcoin sold to pay expenses, realized gain (loss)	1,354,605		1,455,130
Net realized gain, fair value	2,227,493	100,525	2,328,018
Net change in unrealized appreciation/depreciation, fair value	$ (2,102,796,450)	$ 3,806,745,993	$ 1,703,949,543
Ending balance	306,979	252,011	306,979
Ending balance, average cost	$ 17,749,065,590	$ 13,984,500,952	$ 17,749,065,590
Ending balance, fair value	19,453,015,133	17,791,246,945	19,453,015,133
Ending balance, realized gain (loss)	$ 2,227,493	$ 100,525	$ 2,328,018