Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2018

The Company has reserved for future issuance the following number of shares of common stock:

	March 31, 2018		December 31, 2017
Unvested restricted stock		914,648		1,164,040
Common stock options		478,132		666,717
Shares available for issuance under the 2013 Stock Option and Incentive Plan		4,781,183		3,273,334
Shares available for issuance under the 2013 Employee Stock Purchase Plan		788,503		788,503
		6,962,466		5,892,594

The following table shows a roll forward of restricted stock activity pursuant to the 2010 Stock Plan and the 2013 Stock Plan:

A summary of stock option activity under the 2010 Stock Plan and the 2013 Stock Plan for the three months ended March 31, 2018 is as follows:

	Number of Shares			Weighted- Average Exercise Price		Weighted- Average Remaining Contractual Term (In Years)		Aggregate Intrinsic Value
								(in thousands)
Outstanding as of December 31, 2017		666,717		$	19.53		5.6	$	32,450
Granted		—			—
Exercised		(184,783	)		18.56
Forfeited		(3,802	)		25.40
Outstanding as of March 31, 2018		478,132		$	19.86		5.3	$	28,159
Exercisable as of March 31, 2018		440,089		$	18.74		5.1	$	26,409

The Company recorded stock-based compensation expense in the statements of operations and comprehensive loss as follows (in thousands):