Stockholders' Equity and Stock-Based Compensation

6 Months Ended

Jun. 30, 2023

Stockholders' Equity and Stock-Based Compensation

Restricted Stock Awards and Units

Restricted stock award ("RSA") and restricted stock unit ("RSU") activity under our equity incentive plan was as follows:


		Number of Restricted Stock Awards and Units (Thousands)	Weighted-Average Grant Date Fair Value
Balance, December 31, 2022		2,784	$	17.63
	Granted	1,591	11.10
	Vested	(744)	18.53
	Forfeited	(250)	20.79
Balance, June 30, 2023		3,381	14.12

The total fair value of RSUs and RSAs vested during the six months ended June 30, 2023, was $13.8 million. Awards outstanding as of June 30, 2023 include 1.1 million performance-based awards that will vest upon meeting certain performance criteria. Approximately 0.5 million performance-based awards were granted in the second quarter of 2023. These awards vest based on a market metric called Total Shareholder Return ("TSR") for the performance period of three years relative to the TSR of companies in the Russell 2000 Index and had a grant date fair value of $14.12 per share using a Monte Carlo simulation pricing model.

Stock Options

The following table summarizes our stock option activity during the six months ended June 30, 2023:


	Number of Options (Thousands)	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value (Thousands)
Outstanding, December 31, 2022	1,827	$1.29	3.4	$16,156

Options exercised	(217)	1.53

Outstanding, June 30, 2023	1,610	1.27	2.9	22,783
Options exercisable at June 30, 2023	1,610	1.27	2.9	22,783
Options vested as of June 30, 2023, and expected to vest after June 30, 2023	1,610	1.27	2.9	22,783

Total intrinsic value of options exercised for the six months ended June 30, 2023 and 2022, was $1.9 million and $6.9 million, respectively. We received proceeds of $0.3 million and $0.8 million from the exercise of options for the six months ended June 30, 2023 and 2022, respectively.

Stock-Based Compensation

Total stock-based compensation expense was included in our Consolidated Statements of Operations as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2023		2022			2023		2022
Cost of revenues	$	663	$	684		$	1,363	$	1,393
Research and development	2,826		3,117			4,924		6,239
Sales, general and administrative	4,026		2,879			6,731		5,601
	$	7,515	$	6,680		$	13,018	$	13,233

Unrecognized Compensation Costs

As of June 30, 2023, total unrecognized stock-based compensation was $43.4 million, which will be recognized over an average expected recognition period of 2.1 years.