Note 2 - Significant Accounting Policies - Activity in Ether (Details)		1 Months Ended	3 Months Ended				6 Months Ended
	Jun. 24, 2024	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)		Mar. 31, 2025 USD ($)		Jun. 30, 2025 USD ($)
Beginning balance		0	1,191,766		1,071,415		1,071,415
Beginning balance, average cost		$ 0	$ 3,887,465,641		$ 3,543,902,275		$ 3,543,902,275
Beginning balance, fair value		$ 0	$ 2,186,653,058		3,571,669,777	[1]	$ 3,571,669,777	[1]
Ether purchased	3,031	3,031	651,971				954,503
Ether purchased, average cost		$ 10,000,000	$ 1,593,981,362				$ 2,532,610,572
Ether purchased, fair value		$ 10,000,000	$ 1,593,981,362				$ 2,532,610,572
Ether sold for the redemption of shares		0	(74,771)				(256,443)
Ether sold for the redemption of shares, average cost		$ 0	$ (237,314,542)				$ (830,710,219)
Ether sold for the redemption of shares, fair value		0	(144,133,707)				(534,187,709)
Ether sold for the redemption of shares, realized gain (loss)		$ 0	$ (93,180,835)				$ (296,522,510)
Ether sold to pay expenses		0	(393)				(902)
Ether sold to pay expenses, average cost		$ 0	$ (1,234,324)				$ (2,904,491)
Ether sold to pay expenses, fair value		0	(811,088)				(2,168,084)
Ether sold to pay expenses, realized gain (loss)		0	(423,236)				(736,407)
Net realized gain (loss), fair value		0	(93,604,071)	[2]	(203,654,846)		(297,258,917)	[3]
Net change in unrealized appreciation/depreciation, fair value		$ 590,295	$ 854,250,640		$ (1,728,580,085)		$ (874,329,445)
Ending balance		3,031	1,768,573		1,191,766		1,768,573
Ending balance, average cost		$ 10,000,000	$ 5,242,898,137		$ 3,887,465,641		$ 5,242,898,137
Ending balance, fair value		10,590,295	4,396,336,194	[1]	2,186,653,058		4,396,336,194	[1]
Ending balance, realized gain (loss)		$ 0	$ (93,604,071)	[2]	$ (203,654,846)		$ (297,258,917)	[3]

[1] Cost of investment in ether: $5,242,898,137 and $3,543,902,275, respectively.

[2] Includes $807,973 of realized gains and $(94,412,044) of realized losses.

[3] Includes $1,244,204 of realized gains and $(298,503,121) of realized losses.