SIGNIFICANT ACCOUNTING POLICIES - Creation and Redemption of Shares (Details) - Franklin Bitcoin ETF [Member] - USD ($)		3 Months Ended			6 Months Ended
		Sep. 30, 2025		Sep. 30, 2024	Sep. 30, 2025		Sep. 30, 2024
SIGNIFICANT ACCOUNTING POLICIES [Abstract]
Beginning Balance (in Shares)		8,900,000		10,150,000	8,550,000	[1]	8,350,000
Beginning Balance	[2]	$ 260,699,671		$ 348,068,049	$ 240,428,608		$ 280,623,942
Creation of Shares (in Shares)		1,400,000		3,050,000	2,450,000		5,850,000
Creation of Shares	[2]	$ 92,885,565		$ 107,983,445	$ 148,387,208		$ 209,726,374
Redemption of Shares (in Shares)		(300,000)		(950,000)	(1,000,000)		(1,950,000)
Redemption of Shares	[2]	$ (19,374,669)		$ (31,419,769)	$ (54,605,249)		$ (65,718,591)
Ending Balance (in Shares)		10,000,000	[1]	12,250,000	10,000,000	[1]	12,250,000
Ending Balance	[2]	$ 334,210,567		$ 424,631,725	$ 334,210,567		$ 424,631,725

[1] No par value, unlimited amount authorized.

[2] Dollar amount of balance represents the cumulative fair value of creation of shares less the redemption of shares, at the time of the specific creation or redemption.