STOCK BASED COMPENSATION - Valuation assumptions (Details) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2021 |
Dec. 31, 2020 |
|
| Valuation Assumptions | ||
| Dividend yield (as a percent) | 0.00% | |
| Stock options - Service conditions only | ||
| Valuation Assumptions | ||
| Expected term/Time to expiration (in years) | 5 years 9 months 18 days | 6 years 1 month 6 days |
| Volatility | 71.92% | 69.70% |
| Risk-free interest rate | 1.08% | 0.51% |