Stockholders' Equity

3 Months Ended

Mar. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stockholders’ Equity We maintain three share-based employee compensation plans: the 2017 Equity Incentive Plan (“2017 Plan”), the 2014 Equity Incentive Plan (“2014 Plan”), and the 2012 Equity Incentive Plan (“2012 Plan”, and collectively with the 2017 Plan and the 2014 Plan, the “Stock Plans”). The 2017 Plan serves as the successor to the 2014 Plan and 2012 Plan and provides for the grant of incentive stock options to employees, including employees of any parent or subsidiary, and for the grant of nonstatutory stock options, stock appreciation rights, RSAs, RSUs, performance stock awards, performance cash awards, and other forms of stock awards to employees, directors, and consultants, including employees and consultants of our affiliates.

Restricted Stock Units and Restricted Stock Awards

The following table summarizes the RSU and RSA activity during the three months ended March 31, 2023:


	Class A Number of Shares	Weighted- Average Grant Date Fair Value
	(in thousands, except per share data)
Unvested at December 31, 2022	132,392	$	18.28
Granted	23,045	$	10.51
Vested	(21,926)	$	16.70
Forfeited	(5,425)	$	20.93
Unvested at March 31, 2023	128,086	$	17.04

All RSUs and RSAs vest on the satisfaction of a service-based condition. Total unrecognized compensation cost related to outstanding RSUs and RSAs was $1.8 billion as of March 31, 2023 and is expected to be recognized over a weighted-average period of 1.9 years. The service condition for RSUs and RSAs is generally satisfied in equal monthly or quarterly installments over three to four years.

Stock Options

The following table summarizes the stock option award activity under the Stock Plans during the three months ended March 31, 2023:


	Class A Number of Shares	Class B Number of Shares	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value (1)
	(in thousands, except per share data)
Outstanding at December 31, 2022	2,589	570	$	9.68	4.05	$	9,669
Granted	—	—	$	—
Exercised	(3)	(1)	$	7.66
Forfeited	—	—	$	—
Outstanding at March 31, 2023	2,586	569	$	9.68	3.73	$	12,359

(1)The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock option awards and the closing market price of our Class A common stock as of March 31, 2023 and December 31, 2022, respectively.

Total unrecognized compensation cost related to unvested stock options was $0.5 million as of March 31, 2023 and is expected to be recognized over a weighted-average period of 1.2 years.

Stock-Based Compensation Expense by Function

Total stock-based compensation expense by function was as follows:


	Three Months Ended March 31,
	2023		2022
	(in thousands)
Cost of revenue	$	1,885	$	2,446
Research and development	219,850		182,866
Sales and marketing	54,939		42,071
General and administrative	38,257		48,061
Total	$	314,931	$	275,444