Stock Incentive Plans (Tables)

9 Months Ended

Sep. 30, 2017

A summary of share-based awards available for grant under the 2016 Plan is as follows:

	Options Available for Grant
Balance at December 31, 2015		331,938
Additional options authorized		3,865,000
Options granted		(466,914	)
Options forfeited		13,013
Balance at December 31, 2016		3,743,037
Additional options authorized		1,106,966
Options granted		(800,846	)
Options forfeited		15,415
Balance at September 30, 2017		4,064,572

The following table summarizes stock option activity under the 2006 and 2016 Plans, including grants to non-employees:

				Options Outstanding
	Options Outstanding			Weighted- Average Exercise Price Per Share		Weighted- Average Remaining Contractual Life (years)		Aggregate Intrinsic Value (in thousands)
Balances at December 31, 2015		2,685,913		$	4.81		7.63	$	11,589
Options granted		361,385			15.65
Options exercised		(57,067	)		2.33
Options forfeited		(13,013	)		6.92
Balances at December 31, 2016		2,977,218			6.16		6.93	$	70,979
Options granted		449,556			36.24
Options exercised		(649,213	)		3.97
Options forfeited		(11,659	)		15.72
Balances at September 30, 2017		2,765,902		$	11.52		7.29	$	111,634
Options exercisable – September 30, 2017		1,656,418		$	5.43		6.36	$	76,940
Options vested and expected to vest – September 30, 2017		2,698,510		$	11.21		7.25	$	109,750