STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2017


	Three Months Ended
	March 31,
	2017	2016
Option Plan Shares
Risk-free interest rates	2.13 %	1.48% - 1.69%
Expected term (in years)	6.59	6.25 - 6.74
Expected volatility	62.9 %	58.9% - 59.4%
Dividend yield	0 %	0 %
Weighted average fair value per share of options granted during the period	$ 13.20	$ 3.17
Market Measure-Based Shares
Risk-free interest rates	(1)	0.91 %
Expected term (in years)	(1)	2.84
Expected volatility	(1)	68.3 %
Dividend yield	(1)	0 %
Weighted average fair value per share of stock purchase rights granted during the period	(1)	$ 2.32
ESPP Shares
Risk-free interest rates	(2)	(2)
Expected term (in years)	(2)	(2)
Expected volatility	(2)	(2)
Dividend yield	(2)	(2)
Weighted average fair value per share of stock purchase rights granted during the period	(2)	(2)

(1)

The Company did not issue market measure-based shares during the respective period.

(2)

The Company did not issue stock purchase rights under its 2010 Employee Stock Purchase Plan during the respective period.

Summary of stock option activity under the Stock Plans


				Weighted
		Weighted		Average
		Average		Remaining	Aggregate
		Exercise		Contractual	Intrinsic
Options	Shares	Price		Term (Years)	Value(1)
(Aggregate intrinsic value in thousands)
Outstanding, January 1, 2017	3,505,481	$	7.00	5.5
Granted	125,978		21.68
Exercised	(11,704)		4.03
Forfeited	(6,360)		23.38
Outstanding, March 31, 2017	3,613,395	$	7.50	5.5	$	58,283
Exercisable, March 31, 2017	2,647,974	$	6.22	4.3	$	46,103

(1)

The aggregate intrinsic value of options outstanding, exercisable and vested and expected to vest is calculated as the difference between the exercise price of the underlying options and the market price of the Company’s common stock for options that had exercise prices that were lower than the $23.62 market price of the Company’s common stock at March 31, 2017. The total intrinsic value of options exercised during the three months ended March 31, 2017 and 2016 was $0.2 million and $2.1 million, respectively.

Summary of restricted stock and restricted stock unit activity under the Stock Plans


		Weighted
	Restricted	Average Grant
	Shares	Date Fair Value
Outstanding, January 1, 2017	5,601,316	$	9.19
Granted	776,458		21.42
Released	(786,870)		12.39
Forfeited	(37,781)		10.19
Outstanding, March 31, 2017	5,553,123	$	10.47