STOCK-BASED COMPENSATION

9 Months Ended

Sep. 30, 2021

Share-based Payment Arrangement [Abstract]

Stock-based compensation plan overview

The Company maintains three equity incentive plans: the 2018 Equity Incentive Plan (“2018 Plan”), the 2019 Employee, Director and Consultant Equity Incentive Plan (“2019 Plan”) and the 2020 Employee, Director, and Consultant Equity Incentive Plan (“2020 Plan” and collectively, “Incentive Plans”). The 2020 Plan serves as the successor to the 2019 Plan and 2018 Plan and provides for the issuance of incentive stock options, nonqualified stock options, stock grants and stock-based awards to employees, directors, and consultants of the Company. No further awards will be issued under the 2018 Plan and 2019 Plan. Of the total shares available for grant under the 2020 Plan, 2,119,223 remain available as of September 30, 2021.

RSU Activity

RSUs granted to certain executives, employees and members of the Board expire 10 years after the grant date. The awards generally have a time-based vesting requirement (based on continuous employment) and certain awards also have a performance-based vesting requirement (defined as a liquidity event including an initial public offering).

Upon the IPO, the performance-based vesting requirement was satisfied and the employees became vested in the number of RSUs that had satisfied the time-based vesting requirement. The stock-based compensation expense related to remaining service-based awards is recorded over the remaining requisite service period. The following table summarizes the activity related to the Company's RSUs for the nine months ended September 30, 2021. For purposes of this table, vested RSUs represent the shares for which the service condition had been fulfilled as of September 30, 2021:


	Number of RSUs	Weighted average grant date fair value
Balance, January 1, 2021	1,857,444	$	6.55
Granted	71,727	$	58.82
Vested	(652,983)	$	6.89
Balance, September 30, 2021	1,276,188	$	9.32

As of September 30, 2021, total unamortized stock-based compensation cost related to unvested RSUs was $9,309 and the weighted-average period over which the compensation is expected to be recognized is 1.90 years.

The award granted to a former member of the Board (the "former Board member") in July 2020 and modified in November 2020 contains a market-based vesting condition based on the traded value of shares of the Company’s common stock following the IPO over a specific time frame. For this award, the market condition was factored into its fair value and all of the stock-based compensation expense was recognized upon the IPO in December 2020. In July 2021, the market-based vesting condition for this award was satisfied and 148,315 RSUs of the former Board member fully vested. The total shares under the unvested RSUs subject to time-based vesting conditions were 148,315 as of September 30, 2021. For the three and nine months ended September 30, 2021, there were no performance awards with market-based targets granted.

Stock options

The following table summarizes the stock option activity for the nine months ended September 30, 2021:


	Number	Weighted average exercise price		Weighted average grant date fair value		Weighted average remaining contractual term (years)
Outstanding as of January 1, 2021	922,796	$	8.81	$	1.78	8.08
Granted	10,641	$	59.03	$	25.58
Exercised	(125,411)	$	8.43	$	0.73
Forfeited	(8,982)	$	9.81	$	5.25
Outstanding as of September 30, 2021	799,044	$	9.53	$	2.23	7.43

Exercisable as of September 30, 2021	513,571	$	8.51	$	0.87	6.93
Unvested as of September 30, 2021	285,473	$	11.35	$	4.66	2.06
Vested and expected to vest as of September 30, 2021	799,044	$	9.53	$	2.23	7.43

Since options represent equity awards of the Company, such awards are fair valued as of the grant date for the purposes of measurement and recognition under U.S. GAAP. To measure the fair value of an option, the Black-Scholes valuation model was utilized. The valuation model requires the input of highly subjective assumptions. The weighted average assumptions for awards granted as of September 30, 2021 are as follows:


Estimated weighted-average fair value per stock option			$59.03
Volatility			45%
Risk-free rate			0.85%
Dividend yield			Nil
Expected term in years			6.0

As of September 30, 2021, total compensation cost related to unvested awards not yet recognized was $1,120 and the weighted-average period over which the compensation is expected to be recognized is 2.06 years.