Annual report pursuant to Section 13 and 15(d)

Share-based compensation - Fair Value Assumptions (Details)

v3.22.4
Share-based compensation - Fair Value Assumptions (Details)
12 Months Ended
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Assumptions used to estimate the fair values of the share options granted using the Black-Scholes option-pricing model      
Expected term (in years) 5 years 5 years 5 years
Expected dividend yield (as a percent) 0.00% 0.00% 0.00%
Minimum      
Assumptions used to estimate the fair values of the share options granted using the Black-Scholes option-pricing model      
Expected volatility (as a percent) 99.00% 98.00% 90.00%
Risk free rate (as a percent) 0.94% 0.00% 0.00%
Maximum      
Assumptions used to estimate the fair values of the share options granted using the Black-Scholes option-pricing model      
Expected volatility (as a percent) 101.00% 100.00% 99.00%
Risk free rate (as a percent) 3.90% 0.61% 0.42%