Combined Statements of Changes in Net Assets - USD ($)		3 Months Ended		6 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Net assets, beginning of period		$ 559,429,215	$ 373,054,934	$ 410,857,343	$ 341,901,105
Net investment loss		(296,673)	(123,285)	(533,982)	(123,285)
Net realized gain (loss) on investment in bitcoin		7,290,973	(1,325,741)	16,310,184	(1,156,994)
Net change in unrealized appreciation (depreciation) on investment in bitcoin		21,116,054	4,121,057	140,634,961	(32,337,968)
Net increase (decrease) in net assets resulting from operations		28,110,354	2,672,031	156,411,163	(33,618,247)
Capital Share Transactions:
Contributions for Shares issued	[1]	92,885,565	107,983,445	148,387,208	209,726,374
Distributions for Shares redeemed		(19,374,669)	(31,419,769)	(54,605,249)	(65,718,591)
Net increase (decrease) in net assets from capital share transactions		73,510,896	76,563,676	93,781,959	144,007,783
Net assets, end of period		661,050,465	452,290,641	661,050,465	452,290,641
Franklin Bitcoin ETF [Member]
Net assets, beginning of period		559,429,215	373,054,934	410,857,343	341,901,105
Net investment loss		(296,673)	(123,285)	(533,982)	(123,285)
Net realized gain (loss) on investment in bitcoin		7,290,973	(1,325,741)	16,310,184	(1,156,994)
Net change in unrealized appreciation (depreciation) on investment in bitcoin		21,116,054	4,121,057	140,634,961	(32,337,968)
Net increase (decrease) in net assets resulting from operations		28,110,354	2,672,031	156,411,163	(33,618,247)
Capital Share Transactions:
Contributions for Shares issued	[2]	92,885,565	107,983,445	148,387,208	209,726,374
Distributions for Shares redeemed		(19,374,669)	(31,419,769)	(54,605,249)	(65,718,591)
Net increase (decrease) in net assets from capital share transactions		73,510,896	76,563,676	93,781,959	144,007,783
Net assets, end of period		$ 661,050,465	$ 452,290,641	$ 661,050,465	$ 452,290,641

[1] 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.

[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.