v3.26.3
SIGNIFICANT ACCOUNTING POLICIES - Summary of Changes in Shares (Details) - Franklin Crypto Index ETF [Member]
 3 Months Ended 7 Months Ended 9 Months Ended
Feb. 10, 2025
USD ($)
DigitalAssets
CreationUnits
$ / shares
$ / item
shares
Jan. 22, 2025
USD ($)
$ / shares
shares
Sep. 30, 2026
USD ($)
DigitalAssets
shares
Sep. 30, 2025
USD ($)
DigitalAssets
shares
Sep. 30, 2025
USD ($)
DigitalAssets
shares
Sep. 30, 2026
USD ($)
DigitalAssets
shares
Jun. 30, 2026
DigitalAssets
Dec. 31, 2025
DigitalAssets
Jun. 30, 2025
DigitalAssets
Feb. 19, 2025
DigitalAssets
SIGNIFICANT ACCOUNTING POLICIES [Abstract]                    
Beginning Balance (in Shares) | shares     800,000 150,000 100,000 450,000 [1]        
Beginning Balance [2]     $ 17,410,859 $ 3,464,197 [3] $ 2,480,449 [3] $ 11,724,073        
Creation of Shares (in Shares) | shares     100,000 100,000 150,000 450,000        
Creation of Shares [2]     $ 1,608,688 $ 3,060,911 $ 4,044,659 $ 7,295,474        
Redemption of Shares (in Shares) | shares     (100,000) 0 0 (100,000)        
Redemption of Shares [2]     $ (1,981,975) $ 0 $ 0 $ (1,981,975)        
Ending Balance (in Shares) | shares     800,000 [1] 250,000 250,000 800,000 [1]        
Ending Balance [2]     $ 17,037,572 $ 6,525,108 $ 6,525,108 $ 17,037,572        
Creation of Shares | shares     100,000 100,000 150,000 450,000        
Proceeds from issuance of shares         $ 4,044,659 $ 7,295,474        
Redemption of Shares [2]     $ 1,981,975 $ 0 $ 0 $ 1,981,975        
Bitcoin [Member]                    
SIGNIFICANT ACCOUNTING POLICIES [Abstract]                    
Number of Digital Assets per creation unit 11.06240875                  
Quantity of Digital Assets | DigitalAssets 22.1248175   155.373 55.4156 55.4156 155.373 155.4365 87.3467 33.2484 22.1248
Cost of Digital Asset per unit (in Dollars per Item) | $ / item 97,227.8                  
Ethereum [Member]                    
SIGNIFICANT ACCOUNTING POLICIES [Abstract]                    
Number of Digital Assets per creation unit 61.7774073                  
Quantity of Digital Assets | DigitalAssets 123.5548146   806.4596 304.3726 304.3726 806.4596 806.8154 474.4721 182.683 123.5548
Cost of Digital Asset per unit (in Dollars per Item) | $ / item 2,665.23                  
Initial Seed Shares [Member]                    
SIGNIFICANT ACCOUNTING POLICIES [Abstract]                    
Creation of Shares (in Shares) | shares   4,000                
Redemption of Shares $ (100,000)                  
Creation of Shares | shares   4,000                
Shares issued, price per share (in Dollars per share) | $ / shares   $ 25                
Proceeds from issuance of shares   $ 100,000                
Redemption of Shares $ 100,000                  
Seed Creation Units [Member]                    
SIGNIFICANT ACCOUNTING POLICIES [Abstract]                    
Creation of Shares (in Shares) | shares 100,000                  
Creation of Shares | shares 100,000                  
Shares issued, price per share (in Dollars per share) | $ / shares $ 24.8                  
Proceeds from issuance of shares $ 2,480,449.33                  
Number of seed creation units issued | CreationUnits 2                  
[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.
[3] On January 22, 2025, Franklin Resources, Inc. (the “Seed Capital Investor”), an affiliate of the Sponsor, subject to conditions, purchased 4,000 Shares at a per-Share price equal to $25.00 (the “Initial Seed Shares”). Delivery of the Initial Seed Shares was made on January 22, 2025. Total proceeds to the Fund from the sale of the Initial Seed Shares were $100,000. On February 10, 2025, the Initial Seed Shares were redeemed for $100,000, and the Seed Capital Investor purchased two Creation Units in a cash transaction comprised of a total of 100,000 Shares at a per-Share price based on 11.06240875 bitcoin and 61.7774073 ether per Creation Unit, for a total of 22.1248175 bitcoin and 123.5548146 ether (the “Seed Creation Units”). The cash proceeds to the Fund from the sale of the Seed Creation Units were used by the Fund to purchase 22.1248175 bitcoin at the price of $97,227.80 per bitcoin and 123.5548146 ether at the price of $2,665.23 per ether on February 10, 2025 (exclusive of transaction and other costs incurred in connection with the conversion of the cash proceeds to bitcoin and ether respectively, which were paid by the Seed Capital Investor). Thus, the ultimate total proceeds to the Fund from the sale of the Seed Creation Units were $2,480,449.33 (an amount representing 22.1248175 bitcoin and 123.5548146 ether) representing 100,000 shares at a per-Share price equal to $24.80. Further, the transaction and other costs incurred in connection with the Seed Creation Units were paid by the Seed Capital Investor and not borne by the Fund.