STOCK-BASED AWARDS

6 Months Ended

Jun. 30, 2020

Share-based Payment Arrangement [Abstract]

Stock Options

Stock option activity is summarized as follows (in thousands, except per share and term information):


	Number of Shares	Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value¹
Outstanding, December 31, 2019	2,851	$	30.97	3.1	$	78,580

Exercised	(704)	11.58
Forfeited	(162)	41.94
Outstanding, June 30, 2020	1,985	$	36.96	3.1	$	12,688

Exercisable at June 30, 2020	1,985	$	36.96	3.1	$	12,688
Vested and expected to vest at June 30, 2020	1,985	$	36.96	3.1	$	12,688


¹Based on the Company’s closing stock price of $38.56 on June 30, 2020 and $58.55 on December 31, 2019.

There were no stock options granted during the three and six months ended June 30, 2020 and 2019.

Restricted Stock Units

Restricted stock unit (“RSU”) activity is summarized as follows (shares in thousands):


	Number of Shares	Weighted- Average Grant Date Fair Value
Unvested shares at December 31, 2019	3,756	$	47.76
Granted	1,943	34.29
Forfeited	(131)	50.02
Vested	(1,078)	43.80
Unvested shares at June 30, 2020	4,490	$	42.81

Unrecognized compensation expense related to unvested RSUs was $145.8 million at June 30, 2020, which is expected to be recognized over a weighted-average period of 2.7 years.

Performance-Based Restricted Stock Units

Performance-based restricted stock unit (“PRSU”) activity is summarized as follows (shares in thousands):


	Number of Shares	Weighted- Average Grant Date Fair Value
Unvested shares at December 31, 2019¹	1,752	$	44.21
Granted	720	36.06


Unvested shares at June 30, 2020¹	2,472	$	41.83
¹ Assumes maximum achievement of the specified financial targets.

Unrecognized compensation expense related to unvested PRSUs was $18.6 million at June 30, 2020, which is expected to be recognized over a weighted-average period of 1.8 years.

Employee Stock Purchase Plan

Under the Company’s 2010 Employee Stock Purchase Plan (“ESPP”), eligible employees are granted the right to purchase shares at the lower of 85% of the fair value of the stock at the time of grant or 85% of the fair value at the time of exercise. The right to purchase shares is granted semi-annually for six month offering periods each June and December. Under the ESPP, 4,326,341 shares remained available for issuance at June 30, 2020. During the three months ended June 30, 2020, 130,177 shares were purchased under the ESPP.

Stock-Based Compensation

Stock-based compensation expense is reflected in the accompanying condensed consolidated statements of operations as follows (in thousands):


	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2020		2019		2020		2019
Cost of revenue	$	2,122	$	1,786	$	4,823	$	2,922
Sales and marketing	5,628		6,809		14,212		12,856
Research and development	2,724		4,319		7,524		8,515
General and administrative	3,421		6,237		10,506		11,903
Restructuring	208		—		208		—
Total	$	14,103	$	19,151	$	37,273	$	36,196