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Cover - USD ($)
 12 Months Ended
Dec. 31, 2025
Jan. 31, 2026
Jun. 30, 2025
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Annual Report true    
Document Transition Report false    
Document Period End Date Dec. 31, 2025    
Document Fiscal Period Focus FY    
Document Fiscal Year Focus 2025    
Current Fiscal Year End Date --12-31    
Entity File Number 001-41909    
Entity Registrant Name CoinShares Bitcoin ETF    
Entity Central Index Key 0001841175    
Entity Tax Identification Number 86-6430837    
Entity Incorporation, State or Country Code DE    
Entity Address, Address Line One 437 Madison Avenue, 28th Floor    
Entity Address, City or Town New York    
Entity Address, State or Province NY    
Entity Address, Postal Zip Code 10022    
City Area Code (615)    
Local Phone Number 909-6421    
Title of 12(b) Security Common Shares of Beneficial Interest    
Trading Symbol BRRR    
Security Exchange Name NASDAQ    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Non-accelerated Filer    
Entity Small Business true    
Entity Emerging Growth Company true    
Elected Not To Use the Extended Transition Period false    
Entity Shell Company false    
Entity Public Float     $ 77,524,467
Entity Common Stock, Shares Outstanding   21,405,000  
Documents Incorporated by Reference [Text Block] None    
ICFR Auditor Attestation Flag false    
Document Financial Statement Error Correction [Flag] false    
Auditor Name COHEN & COMPANY, LTD.    
Auditor Location Milwaukee, Wisconsin     
Auditor Firm ID 925