Annual report pursuant to Section 13 and 15(d)

Stock Based Compensation (Tables)

v3.22.0.1
Stock Based Compensation (Tables)
 12 Months Ended
Dec. 31, 2021
Share-based Payment Arrangement [Abstract]  
Schedule of Stock-based Compensation Expense The amount of stock-based compensation expense recognized for the years ended December 31, 2021 and 2020 was as follows (in thousands):
 
  Year Ended December 31,
  2021 2020
Research and development $ 1,775  $ 1,340 
General and administrative 5,983  5,131 
Sales and marketing 414  315 
Total stock-based compensation $ 8,172  $ 6,786 
Summary of Option Activity The following table summarizes the Company's service-based option activity for the year ended December 31, 2021:
 
  Options Outstanding
  Number of shares Weighted average exercise price per share Weighted average grant date fair value per share Weighted average remaining contractual term (in years)
Balance at December 31, 2020 8,830,674  $ 3.95  $ 2.36  7.7
Granted 5,336,173  $ 3.18  $ 2.13 
Exercised (580,617) $ 2.70  $ 1.74 
Forfeited (567,758) $ 3.41  $ 2.54 
Expired (367,494) $ 4.47  $ 3.74 
Balance at December 31, 2021 12,650,978  $ 3.69  $ 2.29  8.1
Exercisable at December 31, 2021 5,106,090  $ 4.11  $ 2.37  7.0
The following table summarizes the Company's market-based option activity for the year ended December 31, 2021 (in thousands, except for share amounts):
  Options Outstanding
  Number of shares Weighted average exercise price per share Weighted average remaining contractual term (in years) Aggregate intrinsic value (1)
Balance at December 31, 2020 1,000,000  $ 3.29  9.5 $ 65 
Granted —  $ — 
Balance at December 31, 2021 1,000,000  $ 3.29  2.5 $ — 
Exercisable at December 31, 2021 1,000,000  $ 3.29  2.5 $ — 
(1) The aggregate intrinsic value in the above table represents the total pre-tax amount that a participant would receive if the option had been exercised on the last day of the respective fiscal period. Options with a market value less than its exercise value are not included in the intrinsic value amount.
Schedule of Fair Value Assumptions for Options The following table shows the assumptions used to compute stock-based compensation expense for stock options with service-based vesting conditions granted under the Black-Scholes valuation model for the years ended December 31, 2021 and 2020 and the
assumptions used to compute stock-based compensation expense for market-based stock option grants under a Monte Carlo simulation for the year ended December 31, 2020:
  Year Ended December 31,
Service-based options 2021 2020
Expected term of options (in years) 0.76 — 6.25 1.75 — 6.25
Expected stock price volatility 73.0% — 86.5% 69.9% — 79.0%
Risk-free interest rate 0.07% — 1.34% 0.19% — 1.48%
Expected annual dividend yield 0% 0%
Market-based options
Expected term of options (in years) 4.3 — 5.0
Expected stock price volatility 80.0%
Risk-free interest rate 0.30% 0.34%
Expected annual dividend yield 0%
Nonvested Restricted Stock Shares Activity The following table summarizes the Company's RSU activity for the year ended December 31, 2021:
  RSUs Outstanding
  Number of shares Weighted average grant date fair value
Unvested RSUs at December 31, 2020 155,833  $ 4.91 
Vested (144,583) $ 4.94 
Unvested RSUs at December 31, 2021 11,250  $ 4.50