Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2015

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of Restricted Stock and RSU Activity

A summary of the Company’s restricted stock and RSU activity for the three months ended March 31, 2015 is as follows:

	Shares			Weighted Average Fair Value at Date of Grant per Share
Unvested shares as of December 31, 2014		8,352,714		$	1.46
Granted		3,517			60.75
Vested		(758,136	)		1.43
Forfeited		—			—
Unvested shares as of March 31, 2015		7,598,095		$	1.46

Summary of Stock Option Activity

A summary of the Company’s stock option activity for the three months ended March 31, 2015 is as follows:

	Number of Stock Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life		Aggregate Intrinsic Value (in thousands)
Outstanding as of December 31, 2014		2,720,351	$	7.23		9.75		122,390
Granted		1,120,580		48.73
Exercised		—		—
Cancelled		—		—
Outstanding as of March 31, 2015		3,840,931	$	19.34		9.63	$	159,285
Exercisable as of March 31, 2015		228,425	$	7.33		9.49	$	12,182

Summary of Material Factors Incorporated in Black-Scholes Model in Estimating Fair Value of Options Granted to Employees and Consultants

The fair value of each stock option granted has been determined using the Black-Scholes option pricing model. The material factors incorporated in the Black-Scholes model in estimating the fair value of the options granted to employees and consultants during the three months ended March 31, 2015 included the following:

Assumptions	Three Months Ended March 31, 2015
Risk free interest rate		1.53%–1.94%
Expected volatility		75%
Expected life		6.02-10 years
Expected dividend yield		0%