Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2021

Share-based Payment Arrangement [Abstract]

Summary of Stock Option Activity

A summary of the Company’s stock option activity under the EI Plan is as follows:

	Number of Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2020	30,488,300	$	2.45	8.75	$	885
Granted	5,287,031	4.74
Exercised	(2,695,995)	2.30
Cancelled/forfeited	(941,576)	3.52
Outstanding as of September 30, 2021	32,137,760	$	2.82	8.01	$	213,995

A summary of the Company’s stock option activity under the STI Plan is as follows:

	Number of Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding as of December 31, 2020	6,490,208	$	2.49	9.26	$	1,174
Granted	5,516,399	7.82		—	—
Exercised	(1,630,925)	2.54		—	—
Cancelled/forfeited	(846,200)	2.67		—	—
Outstanding as of September 30, 2021	9,529,482	$	5.55	8.27	$	39,171

Summary of Weighted-Average Assumptions

The weighted-average assumptions used in the Black-Scholes option pricing model for awards granted during the nine months ended September 30, 2021 are as follows:

Risk-free interest rate:	0.79	%
Expected term (in years):	6.05
Expected volatility:	42.10	%
Dividend yield:	0.00	%

The weighted-average assumptions used in the Black-Scholes option pricing model for awards granted during the nine months ended September 30, 2021 are as follows:

Risk-free interest rate:	1.39	%
Expected term (in years):	9.06
Expected volatility:	35.86	%
Dividend yield:	0.00	%

Schedule of Stock-Based Compensation Expense

The following table presents stock-based compensation expense included in each respective expense category in the unaudited Condensed Consolidated Statements of Operations and Other Comprehensive Loss for the three and nine months ended September 30, 2021:

	Three Months Ended September 30,
	2021		2020
Research and development	$	1,879	$	933
Sales and marketing	538		215
General and administrative	2,636		2,267
	$	5,053	$	3,415

	Nine Months Ended September 30,
	2021		2020
Research and development	$	2,873	$	2,493
Sales and marketing	847		633
General and administrative	4,801		3,940
	$	8,521	$	7,066

The following table presents stock-based compensation expense included in each respective expense category in the unaudited Condensed Consolidated Statements of Operations and Other Comprehensive Loss for the three and nine months ended September 30, 2021:

Restricted stock awards for employee bonus, net	Three and Nine Months Ended September 30,
	2021		2020
Research and development	$	6,061	$	—
Sales and marketing	1,797		—
General and administrative	6,762		—
	$	14,620	$	—