Stockholders' Equity

9 Months Ended

Oct. 03, 2020

Share-based Payment Arrangement [Abstract]

Stockholders’ Equity

Equity Incentive Plans

In May 2015, the Company’s board of directors and stockholders adopted and approved the 2015 Equity Incentive Plan (the “2015 Plan”). The 2015 Plan became effective on June 16, 2015 and serves as the successor to the Amended and Restated 2007 Stock Plan (the “2007 Plan”). The Company ceased granting awards under the 2007 Plan upon the effectiveness of the 2015 Plan. However, any outstanding stock options and restricted stock units (“RSUs”) granted under the 2007 Plan remain subject to the terms of the 2007 Plan. As of October 3, 2020, 33.7 million shares of Class A common stock were reserved and available for future issuance under the 2015 Plan.

Stock Options

Stock option activity under the equity incentive plans was as follows (in thousands, except per share amounts):


	Stock Options Outstanding
	Number of Shares Subject to Stock Options	Weighted– Average Exercise Price		Aggregate Intrinsic Value (1)
Balance—December 31, 2019	12,871	$	3.51
Granted	—
Exercised	(1,469)	$	2.04
Forfeited or canceled	(147)	$	6.96
Balance—October 3, 2020	11,255	$	3.66	$	40,248

Stock options vested and expected to vest—October 3, 2020	11,255	$	3.66	$	40,248
Stock options exercisable—October 3, 2020	11,255	$	3.66	$	40,248

(1) The aggregate intrinsic values of stock options outstanding, exercisable, vested and expected to vest as of October 3, 2020 were calculated as the difference between the exercise price of the stock options and the fair value of the Class A common stock of $6.92 as of October 3, 2020.

Restricted Stock Units

RSU activity under the equity incentive plans was as follows (in thousands, except per share amounts):


	RSUs Outstanding	Weighted- Average Grant Date Fair Value
Unvested balance—December 31, 2019	18,932	$	5.68
Granted	9,904	$	6.41
Vested	(8,808)	$	6.16
Forfeited or canceled	(944)	$	5.90
Unvested balance—October 3, 2020	19,084	$	5.83

Stock-Based Compensation Expense

Total stock-based compensation expense recognized was as follows (in thousands):


	Three Months Ended				Nine Months Ended
	October 3, 2020		September 28, 2019		October 3, 2020		September 28, 2019
Cost of revenue	$	1,846	$	1,446	$	6,059	$	4,397
Research and development	10,633		10,557		33,194		34,437
Sales and marketing	2,701		2,587		8,376		8,900
General and administrative	3,197		3,494		10,248		11,441
Total stock-based compensation expense	$	18,377	$	18,084	$	57,877	$	59,175

As of October 3, 2020, the total unrecognized stock-based compensation expense related to unvested stock options and RSUs was $97.4 million, which the Company expects to recognize over an estimated weighted average period of 1.8 years.