Note 2 - Significant Accounting Policies - Activity in Ether (Details)			3 Months Ended
		Jun. 24, 2024	Mar. 31, 2025 USD ($)
Beginning balance			1,071,415
Beginning balance, average cost			$ 3,543,902,275
Beginning balance, fair value	[1]		$ 3,571,669,777
Ether purchased		3,031	302,532
Ether purchased, average cost			$ 938,629,210
Ether purchased, fair value			$ 938,629,210
Ether sold for the redemption of shares			(181,672)
Ether sold for the redemption of shares, average cost			$ (593,395,677)
Ether sold for the redemption of shares, fair value			(390,054,002)
Ether sold for the redemption of shares, realized gain (loss)			$ (203,341,675)
Ether sold to pay expenses			(509)
Ether sold to pay expenses, average cost			$ (1,670,167)
Ether sold to pay expenses, fair value			(1,356,996)
Ether sold to pay expenses, realized gain (loss)			(313,171)
Net realized loss, fair value	[2]		(203,654,846)
Net change in unrealized appreciation/depreciation, fair value			$ (1,728,580,085)
Ending balance			1,191,766
Ending balance, average cost			$ 3,887,465,641
Ending balance, fair value	[1]		2,186,653,058
Ending balance, realized gain (loss)	[2]		$ (203,654,846)

[1] Cost of investment in ether: $3,887,465,641 and $3,543,902,275, respectively.

[2] Includes $436,231 of realized gains and $(204,019,077) of realized losses.