Combined Statements of Cash Flows - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Cash Flows from Operating Activities:
Net increase (decrease) in net assets resulting from operations	$ 28,110,354	$ 2,672,031	$ 156,411,163	$ (33,618,247)
Adjustments to reconcile net increase (decrease) in net assets resulting from operations to net cash provided by (used in) operating activities:
Purchases of bitcoin			(148,387,208)	(209,726,374)
Sales of bitcoin			55,143,923	65,776,280
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	(21,116,054)	(4,121,057)	(140,634,961)	32,337,968
Change in operating assets and liabilities:
Sponsor's fee payable			(4,692)	65,596
Net cash provided by (used in) operating activities			(93,781,959)	(144,007,783)
Cash Flows from Financing Activities:
Proceeds from issuance of Shares			148,387,208	209,726,374
Payments on Shares redeemed			(54,605,249)	(65,718,591)
Net cash provided by (used in) financing activities			93,781,959	144,007,783
Cash
Net decrease in cash			0	0
Cash, beginning of period			0	0
Cash, end of period	0	0	0	0
Franklin Bitcoin ETF [Member]
Cash Flows from Operating Activities:
Net increase (decrease) in net assets resulting from operations	28,110,354	2,672,031	156,411,163	(33,618,247)
Adjustments to reconcile net increase (decrease) in net assets resulting from operations to net cash provided by (used in) operating activities:
Purchases of bitcoin			(148,387,208)	(209,726,374)
Sales of bitcoin			55,143,923	65,776,280
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	(21,116,054)	(4,121,057)	(140,634,961)	32,337,968
Change in operating assets and liabilities:
Sponsor's fee payable			(4,692)	65,596
Net cash provided by (used in) operating activities			(93,781,959)	(144,007,783)
Cash Flows from Financing Activities:
Proceeds from issuance of Shares			148,387,208	209,726,374
Payments on Shares redeemed			(54,605,249)	(65,718,591)
Net cash provided by (used in) financing activities			93,781,959	144,007,783
Cash
Net decrease in cash			0	0
Cash, beginning of period			0	0
Cash, end of period	$ 0	$ 0	$ 0	$ 0