Employee benefit plans

9 Months Ended

Sep. 30, 2022

Share-based Payment Arrangement [Abstract]

Equity incentive plans. The Company has outstanding equity grants from its three stock-based employee compensation plans: the 2014 Equity Incentive Plan (2014 Plan), the 2010 Equity Incentive Plan (2010 Plan) and the 2014 Employee Stock Purchase Plan (ESPP). No new options or awards have been granted under the 2010 Plan since June 2014. Outstanding options and awards under the 2010 Plan continue to be subject to the terms and conditions of the 2010 Plan. Options granted under the 2014 Plan generally expire within ten years from the date of grant and generally vest over one to four years. Restricted stock units (RSUs) granted under the 2014 Plan generally vest over two to four years based upon continued service and are settled at vesting in shares of the Company’s Class A common stock. Performance stock units (PSUs) granted under the 2014 Plan generally vest over three years based upon continued service and the Company achieving certain financial and operating targets, and are settled at vesting in shares of the Company’s Class A common stock. The Company accounts for forfeitures of stock-based payment awards in the period they occur. The ESPP allows eligible employees to purchase shares of the Company’s Class A common stock through payroll deductions at a price equal to 85% of the lesser of the fair market value of the stock as of the first date or the ending date of each six-month offering period. For additional information regarding the Company’s equity incentive plans, refer to the 2021 Annual Report.

Stock options

A summary of the Company’s stock option activity for the nine months ended September 30, 2022 is as follows:


	Shares (in thousands)	Weighted-average exercise price		Weighted-average remaining contractual term (in years)	Aggregate intrinsic value (in thousands)
Outstanding at December 31, 2021	3,080	$	9.18	5.92	$	8,735
Granted	321	8.70
Exercised	(44)	4.70
Forfeited/Cancelled	(189)	6.67
Outstanding at September 30, 2022	3,168	$	9.34	5.42	$	463

Vested and expected to vest at September 30, 2022	3,168	$	9.34	5.42	$	463
Exercisable at September 30, 2022	2,447	$	10.05	4.55	$	259

The aggregate intrinsic value of the stock options outstanding as of September 30, 2022 represents the value of the Company’s closing stock price on September 30, 2022 in excess of the exercise price multiplied by the number of options outstanding.

Restricted stock units

A summary of the Company’s RSU activity for the nine months ended September 30, 2022 is as follows:


	Shares (in thousands)	Weighted-average grant date fair value
Non-vested shares at December 31, 2021	8,714	$	6.52
Granted	4,452	8.30
Vested	(4,116)	6.27
Forfeited	(855)	6.51
Non-vested shares at September 30, 2022	8,195	$	7.62

Performance stock units

A summary of the Company’s PSU activity for the nine months ended September 30, 2022 is as follows:


	Shares (in thousands)	Weighted-average grant date fair value
Non-vested shares at December 31, 2021	1,134	$	6.68
Granted	604	8.70
Vested	(620)	6.55
Forfeited	(36)	6.76
Non-vested shares at September 30, 2022	1,082	$	7.88

Employee stock purchase plan. For the nine months ended September 30, 2022 and 2021, the Company issued 0.7 million and 0.8 million shares under its ESPP, respectively, at weighted-average prices of $6.72 and $5.28, respectively.

Stock-based compensation expense. The Company measures compensation expense for all stock-based payment awards based on the estimated fair values on the date of the grant. The fair value of stock options granted and ESPP issuance is estimated using the Black-Scholes option pricing model. The fair value of RSUs and PSUs are determined using the Company’s closing stock price on the date of grant. There have been no significant changes in the Company’s valuation assumptions from those disclosed in its 2021 Annual Report.

The following table summarizes stock-based compensation expense included in the Condensed Consolidated Statements of Operations:


	Three months ended September 30,				Nine months ended September 30,
(in thousands)	2022		2021		2022		2021
Cost of revenue	$	441	$	483	$	1,371	$	1,420
Research and development	4,395		4,380		12,958		13,131
Sales and marketing	1,819		1,950		6,171		5,968
General and administrative	2,684		2,516		8,926		7,708
Total stock-based compensation expense	$	9,339	$	9,329	$	29,426	$	28,227

The income tax benefit related to stock-based compensation expense was $2.1 million and $6.5 million for the three and nine months ended September 30, 2022, respectively. The income tax benefit related to stock-based compensation expense was $2.1 million and $6.5 million for the three and nine months ended September 30, 2021. See Note 8, Income taxes, for additional details.

At September 30, 2022, total unearned stock-based compensation of $57.3 million related to stock options, RSUs, PSUs and ESPP shares is expected to be recognized over a weighted-average period of 1.99 years.