Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Canceled/expired

Stock-based employee compensation expense

The following table summarizes the amount of share-based compensation expense by line item on the statements of operations:

Share-based compensation expense		Three Months Ended
		March 31,
(in thousands)		2021		2020
Research and development expense	$	1,184	$	39
Sales, marketing, general and administrative expense		454		150
	$	1,638	$	189

Options activity and positions

The following table summarizes shares, weighted-average exercise price, weighted-average remaining contractual term and aggregate intrinsic value of options outstanding and options exercisable as of March 31, 2021:

				Weighted-
			Weighted-	Average
			Average	Remaining		Aggregate
			Exercise	Contractual		Intrinsic
Options	Shares		Price	Term (years)		Value
Outstanding as of March 31, 2021	2,096,000	$	1.32	6.8	$	36,104,000
Exercisable as of March 31, 2021	1,115,000	$	1.77	5.7	$	18,706,000

Share-based Payment Arrangement, Restricted Stock Unit, Activity

The following table summarizes activity and positions with respect to RSUs and PSUs for the three months ended March 31, 2021:

			Weighted-average
	Shares		price
Unvested as of December 31, 2020	1,983,000	$	0.76
Granted	899,000		7.10
Vested	(368,000)		0.10
Forfeited	(69,000)		0.98
Unvested as of March 31, 2021	2,445,000	$	3.18