Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Stock-Based Compensation

Summary of compensation costs related to stock-based awards

The following table summarizes compensation costs related to our stock-based awards (in thousands, except per share data):

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2021		2020		2021		2020
Cost of revenue	$	36	$	27	$	75	$	55
Selling, general and administrative		802		492		1,442		984
Research and development		137		122		274		245
Total stock-based compensation		975		641		1,791		1,284
Tax effect on stock-based compensation		—		—		—		—
Net effect on net income	$	975	$	641	$	1,791	$	1,284

Summary of stock option activity

The following table summarizes the stock option transactions during the six months ended June 30, 2021 (in thousands, except per share data):

				Weighted-
				average
		Weighted-		Remaining
	Number of	average		Contractual	Aggregate
	Options	Exercise		Life	Intrinsic
Stock Options	Outstanding	Price		(in years)	Value
Balance as of January 1, 2021	1,885	$	4.42	6.17	$	9,713
Granted	—		—
Exercised	(348)		3.23
Canceled and expired	—		—
Balance as of June 30, 2021	1,537	$	4.69	6.16	$	9,678
Options vested as of June 30, 2021 and unvested options expected to vest, net of forfeitures	1,530	$	4.69	6.15	$	9,619
Options exercisable as of June 30, 2021	1,168	$	4.94	5.56	$	7,051

Summary of restricted stock awards activity

A summary of activity related to restricted stock awards for the six months ended June 30, 2021 is presented below (in thousands, except per share data):

		Weighted-Average
		Grant Date
Stock Awards	Shares	Share Value
Non-vested as of January 1, 2021	1,022	$	5.27
Granted	65	$	11.63
Vested	(136)	$	5.89
Forfeited	(1)	$	5.21
Non-vested as of June 30, 2021	950	$	5.62

Summary of unvested at-risk performance shares

A summary of the status of our unvested at-risk, performance shares as of June 30, 2021 is presented below (in thousands, except per share data):

		Weighted-Average
		Grant Date
Stock Awards	Shares*	Share Value
Non-vested as of January 1, 2021	—	$	—
Granted	101	$	15.37
Vested	—	$	—
Forfeited	—	$	—
Non-vested as of June 30, 2021	101	$	15.37