Quarterly report pursuant to Section 13 or 15(d)

SHARE-BASED COMPENSATION - Activity of Stock Options (Details)

v3.21.2
SHARE-BASED COMPENSATION - Activity of Stock Options (Details) - USD ($)
$ / shares in Units, $ in Thousands
9 Months Ended 12 Months Ended
Sep. 30, 2021
Dec. 31, 2020
Stock Options    
Outstanding, beginning balance (in shares) 896,888  
Granted (in shares) 64,736  
Exercised (in shares) (40,942)  
Forfeited (in shares) (40,736)  
Expired (in shares) (87,300)  
Outstanding, ending balance (in shares) 792,646 896,888
Vested and expected to vest (in shares) 781,365  
Vested and exercisable (in shares) 435,013  
Weighted-Average Exercise Price    
Outstanding, beginning (USD per share) $ 5.22  
Granted (USD per share) 13.81  
Exercised (USD per share) 0.24  
Forfeited (USD per share) 10.75  
Expired (USD per share) 9.40  
Outstanding, ending (USD per share) 5.96 $ 5.22
Vested and expected to vest (USD per share) 5.89  
Vested and exercisable (USD per share) $ 6.24  
Weighted-Average Remaining Contractual Term (Years) and Aggregate Intrinsic Value    
Outstanding term 3 years 10 months 28 days 3 years 11 months 15 days
Granted term 9 years 5 months 23 days  
Vested and expected to vest term 3 years 11 months 1 day  
Vested and exercisable term 3 years 7 months 6 days  
Outstanding $ 1,430 $ 2,889
Exercised 434  
Vested and expected to vest 1,460  
Vested and exercisable $ 743