FINANCIAL HIGHLIGHTS - Summary of Per Share Performance (Details) - Franklin Bitcoin ETF [Member] - $ / shares		3 Months Ended
		Jun. 30, 2025	Jun. 30, 2024
FINANCIAL HIGHLIGHTS [Abstract]
Net asset value per Share, beginning of period (in dollars per share)		$ 48.05	$ 40.95
Net investment loss (in dollars per share)	[1]	(0.03)	0
Net realized and unrealized gain (loss) on investment in bitcoin (in dollars per share)		14.84	(4.2)
Net change in net assets from operations (in dollars per share)	[2]	14.81	(4.2)
Net asset value per Share, end of period (in dollars per share)		$ 62.86	$ 36.75
Total return, at net asset value	[3],[4]	30.82%	(10.26%)
Net investment loss	[5]	(0.19%)	0.00%
Gross expenses	[5]	0.19%	0.19%
Net expenses	[5],[6]	0.19%	0.00%

[1] Calculated using average Shares outstanding.

[2] The amount shown for a share outstanding may not agree with the change in the aggregate gains and losses for the period because of the timing of transactions in the Fund’s shares in relation to fluctuating market values for the Fund.

[3] Calculation based on the change in net asset value of a Share during the period. Total return for periods of less than a year are not annualized.

[4] Total Return at NAV is calculated assuming an initial investment made at the NAV at the beginning of the period, and redemption of Shares at NAV on the last day of the period. Total Return at NAV as shown above includes adjustments in accordance with U.S. GAAP.

[5] Annualized.

[6] For the period from January 12, 2024 to August 2, 2024, the Sponsor waived a portion of the Sponsor's Fee so that the Sponsor's Fee after the fee waiver would be equal to 0.00% of the net asset value of the Fund for the first $10.0 billion of the Fund's assets. Prior to the implementation of the waiver, for the one day period January 11, 2024, the Fund accrued the Sponsor fee of 0.29% ($21).