v3.26.1
Share capital (Details) - CHF (SFr)
 1 Months Ended 12 Months Ended
Feb. 20, 2024
Dec. 31, 2023
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Share capital          
Number of shares at beginning of period     (56,061,527)    
Number of shares at beginning of period     128,292,969 125,195,393  
Sale of treasury shares     19,612,752 3,050,665  
Movement of shares under liquidity agreement     (28,329) 55,450  
Acquisition of shares forfeited from DSPPP     (45,578) (8,539)  
Number of shares at end of period     (70,822,682) (56,061,527)  
Number of shares at end of period   125,195,393 147,831,814 128,292,969 125,195,393
Number of shares reclassed as treasury shares under IFRS 2     (29,904,690) (29,950,268)  
Number of shares including IFRS 2 shares     117,927,124 98,342,701  
Par value per share       SFr 0.01  
Treasury shares     SFr 1,014,980 SFr 869,708  
Share sale price     SFr 0.063 SFr 0.08  
Gross proceeds from sale of treasury shares, excluding liquidity agreement     SFr 1,230,103 SFr 235,257  
Gross proceeds from sale of treasury shares     SFr 1,228,733 240,899 SFr 2,350,512
Number of shares registered in commercial register during period 6,120,000        
Treasury shares sold not under sale agency agreement          
Share capital          
Sale of treasury shares     10,966,666    
Share sale price     SFr 0.06    
Number of warrants granted     2,741,666    
Exercise price of granted warrants     SFr 0.06    
Exercise period of warrants granted     5 years    
Value of warrants     SFr 65,609    
Treasury shares sold under sale agency agreement          
Share capital          
Sale of treasury shares     8,646,086    
Share sale price     SFr 0.066    
Gross proceeds from sale of treasury shares     SFr 572,102    
Kepler | Treasury Shares Reserve          
Share capital          
Treasury shares     144,951 116,622  
Kepler | Other financial assets          
Share capital          
Treasury shares     SFr 5,130 SFr 6,496  
Common shares          
Share capital          
Number of shares at beginning of period     184,354,496 184,354,496  
Issuance of treasury shares     34,300,000    
Number of shares at end of period   184,354,496 218,654,496 184,354,496 184,354,496
Number of common shares including IFRS 2 shares     218,654,496 184,354,496  
Exercise of pre-funded warrants   6,120,000      
Share capital as registered in commercial register   SFr 1,782,344.96     SFr 1,782,344.96
Number of shares registered in commercial register   178,234,496     178,234,496
Treasury shares          
Share capital          
Number of shares at beginning of period     (56,061,527) (59,159,103)  
Issuance of treasury shares     (34,300,000)    
Sale of treasury shares     19,612,752 3,050,665  
Movement of shares under liquidity agreement     (28,329) 55,450  
Acquisition of shares forfeited from DSPPP     (45,578) (8,539)  
Number of shares at end of period   (59,159,103) (70,822,682) (56,061,527) (59,159,103)
Number of shares reclassed as treasury shares under IFRS 2     (29,904,690) (29,950,268)  
Number of shares including IFRS 2 shares     (100,727,372) (86,011,795)  
American Depositary Shares          
Share capital          
Number of shares at beginning of period          
Number of shares at end of period     (30,000,000)