Common Stock (Tables)

9 Months Ended

Sep. 30, 2018

Equity [Abstract]

Summary of Stock Option Plan

Activity under the Company’s stock option plan is set forth below:

						Weighted-
				Weighted		Average
				Average		Remaining		Aggregate
				Exercise		Contractual		Intrinsic Value
	Number of Shares			Price		Term (Years)		(in thousands)
Balance—December 31, 2017		3,733,544		$	4.53		7.9	$	25,386
Granted		1,000		$	13.89
Exercised		(756,540	)	$	3.31
Canceled		(597,834	)	$	6.24
Balance—September 30, 2018		2,380,170		$	4.49		7.2	$	19,745
Vested and exercisable - September 30, 2018		1,500,147		$	3.63		6.6	$	13,736
Vested and exercisable - December 31, 2017		1,648,917		$	2.89		6.7	$	13,924

Schedule of Fair Value Assumptions for Option Grants

The calculated fair value of option grants was estimated using the Black-Scholes model with the following assumptions for which options were granted:

	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2018	2017	2018	2017
Risk-free interest rate	2.87%	1.94% - 2.40%	2.87%	1.89% - 2.40%
Expected term	6.1 yrs	6.1 - 10.0 yrs	6.1 yrs	6.1 - 10.0 yrs
Expected dividends	0%	0%	0%	0%
Volatility	35%	27% - 30%	35%	27% - 30%

Summary of Company 's RSU

Activity under the Company’s RSU is set forth below:

	Number of Shares
Balance—December 31, 2017		35,029
Granted		1,486,287
Released		(23,429	)
Canceled		(92,101	)
Balance—September 30, 2018		1,405,786

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense recognized in the condensed consolidated statements of operations and comprehensive loss for options, restricted stock units and ESPP was as follows (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2018		2017		2018		2017
Cost of revenue	$	44	$	12	$	90	$	26
Research and development		1,326	251			2,420	544
Sales and marketing	239		46		512		110
General and administrative	514		99			1,241	277
Total	$	2,123	$	408	$	4,263	$	957