Stock-Based Awards (Tables)

3 Months Ended

Mar. 31, 2019

Summary of Stock Option Activity

The following table summarizes stock options activity for the three months ended March 31, 2019 (in thousands):

	Number of Shares
Outstanding at December 31, 2018		3,603
Granted		57
Exercised		(28	)
Forfeited or expired		(178	)
Outstanding at March 31, 2019		3,454
Vested and exercisable at March 31, 2019		1,066

Summary of Stock-Based Compensation Expense

The following table presents the effects of stock-based compensation in our condensed consolidated statements of operations during the periods presented (in thousands):

	Three Months Ended March 31,
	2019		2018
Cost of revenue	$	144	$	83
Research and development expense		1,071		759
Sales and marketing expense		1,290		757
General and administrative expense		972		466
Total stock-based compensation expense	$	3,477	$	2,065

Restricted Stock Units

Summary of Restricted Stock Units

The following table summarizes activity for restricted stock units, or RSUs, and RSUs with performance conditions, or PSUs, for the three months ended March 31, 2019 (in thousands):

	Number of Shares
	RSUs		PSUs
Outstanding at December 31, 2018		32		—
Granted		3		242
Vested		—		—
Forfeited		—		—
Outstanding at March 31, 2019		35		242