v3.26.1
Description of Business and Basis of Presentation (Details) - USD ($)
3 Months Ended 6 Months Ended 9 Months Ended 12 Months Ended
Sep. 05, 2025
Sep. 30, 2025
Sep. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Sep. 30, 2025
Sep. 30, 2024
Dec. 31, 2025
Dec. 31, 2024
Description of Business and Basis of Presentation                  
Cash and cash equivalents               $ 23,719,422 $ 6,728,895
Net loss   $ (45,414,335) $ (1,220,296) $ (6,936,475) $ (1,689,843) $ (52,350,810) $ (2,910,139) (61,002,954) (5,713,369)
Net cash used in operating activities               (13,051,195) (2,799,642)
Accumulated deficit               (66,727,099) $ (5,724,145)
Issuance of common stock to PIPE investors               $ 30,000,000  
Placement Agent Warrants                  
Description of Business and Basis of Presentation                  
Warrants to purchase (in shares) 586,666                
Private Placement                  
Description of Business and Basis of Presentation                  
Issuance of common stock (in shares) 10,000,000                
Purchase price (in dollars per share) $ 3                
Issuance of common stock to PIPE investors $ 30,000,000                
Legacy Deep Fission                  
Description of Business and Basis of Presentation                  
Number of shares issued per share (in shares) 17.32141                
Shares issued for services (in shares) 85,000