STOCK BASED COMPENSATION (Tables)

6 Months Ended

Jun. 30, 2021

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of stock-based compensation expense

Total stock-based compensation expense related to all of the Company’s stock-based awards granted is reported in the condensed consolidated statements of operations as follows (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2021		2020		2021		2020
Research and development	$	1,838	$	569	$	2,755	$	1,283
General and administrative expense		1,355		217		2,194		454
Sales and marketing expense		577		213		921		421
Cost of sales		229		75		346		175
Total stock-based compensation expenses	$	3,999	$	1,074	$	6,216	$	2,333

Schedule of option activity

There were 21,810,237 shares available for award under the 2020 Plan at June 30, 2021. The option activity of the Plans for the six months ended June 30, 2021, is as follows (shares in thousands):

				Weighted-Average
		Weighted-Average		Remaining	Aggregate
	Number of	Exercise Price		Contractual Term	Intrinsic Value
	Shares	per Share		(in years)	(in thousands)
Outstanding at January 1, 2021	19,553	$	1.53	7.75	$	306,408
Granted	—	$	—
Exercised	(2,846)	$	1.29
Forfeited/expired	(313)	$	1.43
Outstanding at June 30, 2021	16,394	$	1.57	7.40	$	162,737
Options vested at June 30, 2021	9,451	$	1.62	6.27	$	93,385
Options vested or expected to vest at June 30, 2021	15,807	$	1.58	7.34	$	156,825

Schedule of RSU activity

RSU activity under the 2020 Plan for the six months ended June 30, 2021 is as follows (shares in thousands):

	Shares Subject	Weighted-Average
	to Vesting	Grant Date Fair Value
Balance of unvested shares as of January 1, 2021	683	$ 8.02
Granted	4,461	$ 15.38
Vested	(44)	$ 8.13
Cancelled/Forfeited	(5)	$ 7.98
Balance of unvested shares as of June 30, 2021	5,095	$ 14.52

Consultant

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of assumptions using Black-Scholes option-pricing model

	Six Months Ended
	June 30, 2020
Risk‑free interest rate		0.8	%
Expected volatility		54.3	%
Expected life (in years)		10.0
Expected dividend yield		—
Fair value of Common Stock	$	3.34

Employee

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of assumptions using Black-Scholes option-pricing model

	Three Months Ended			Six Months Ended
	June 30, 2020			June 30, 2020
Risk‑free interest rate		0.4 % – 0.9	%		0.4 % – 0.9	%
Expected volatility		52.7 % – 54.2	%		52.7 % – 54.2	%
Expected life (in years)		5.9 – 6.3			5.9 – 6.3
Expected dividend yield		—			—
Fair value of Common Stock	$	3.34		$	3.34