v3.26.1
Cover Page - shares
3 Months Ended
Mar. 31, 2026
Apr. 30, 2026
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q1  
Document Period End Date Mar. 31, 2026  
Document Quarterly Report true  
Document Transition Report false  
Current Fiscal Year End Date --12-31  
Entity Registrant Name Grayscale Bitcoin Mini Trust ETF  
Entity Central Index Key 0002015034  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Filer Category Large Accelerated Filer  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity File Number 001-42194  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 99-6383052  
Entity Address, Address Line One c/o Grayscale Investments Sponsors, LLC  
Entity Address, Address Line Two 290 Harbor Drive, 4th Floor  
City Area Code 212  
Local Phone Number 668-1427  
Entity Address, City or Town Stamford  
Entity Address, Postal Zip Code 06902  
Entity Address, State or Province CT  
Entity Common Stock, Shares Outstanding   119,829,963
Title of 12(b) Security Grayscale Bitcoin Mini Trust ETF Shares  
Trading Symbol BTC  
Security Exchange Name NYSEArca