Share-based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Summary of Share-Based Compensation Expense

For the years ended December 31, 2019 and 2018, the following table presents total share-based compensation expense in each functional line item on the consolidated statements of operations (in thousands):

	Year Ended December 31,
	2019		2018
Cost of revenues	$	1,133	$	390
Research and development	1,548		1,017
Sales and marketing	1,669		970
General and administrative	2,952		2,499
Total	$	7,302	$	4,876

Share-based Compensation Stock Option Fair Value Assumptions

The following table presents the weighted-average assumptions used in the Black-Scholes valuation model by the Company in calculating the fair value of each stock option granted:

	Year Ended December 31,
	2019		2018
Expected dividend yield	—	%	—	%
Risk-free interest rate	1.8	%	2.8	%
Volatility	81	%	84	%
Expected term (in years)	5.8		5.8

Summary of Stock Option Activity

The following table summarizes the Company’s stock option activity for the years ended December 31, 2019 and 2018 (dollars in thousands, except per share data):

	Stock Options Outstanding		Weighted-Average Exercise Price Per Option		Weighted-Average Remaining Contractual Term (in years)	Aggregate Intrinsic Value
Outstanding — December 31, 2018	8,796,212		$	2.10
Granted	2,660,936		5.17
Exercised	(1,489,067	)	1.69
Canceled	(923,777	)	3.64
Outstanding — December 31, 2019	9,044,304		$	2.91	8.30	$	39,997
Vested and Expected to Vest — December 31, 2019	7,814,925		$	2.75	8.17	$	35,753
Exercisable — December 31, 2019	3,648,992		$	1.93	7.28	$	19,735

Summary of Restricted Stock Unit Activity

A summary of restricted stock unit activity under all plans for the year ended December 31, 2019 is presented below:

	Number of Shares		Weighted-Average Grant-Date Fair Value
Non-vested — December 31, 2018	454,382		$	2.17
Granted	870,150		5.07
Vested	(809,482	)	4.20
Forfeited	(114,735	)	3.66
Non-vested — December 31, 2019	400,315		$	3.95