Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2020

Schedule of Stock-based Compensation Expense

Stock-based compensation expense included in the Company’s condensed consolidated statements of comprehensive loss is allocated as follows (in thousands):



	Three Months Ended March 31,
	2020		2019
Research and development	$	786	$	221
General and administrative	1,741		645
Sales and marketing	1,395		276
	$	3,922	$	1,142

Schedule of Option Awards Fair Valuation Assumptions

The option awards issued under the 2014 Stock Option Plan (the “2014 Plan”) and the 2018 Omnibus Incentive Plan (the “2018 Plan”) were measured based on fair value. The Company’s fair value calculations were made using the Black-Scholes option pricing model with the following assumptions:



	Three Months Ended March 31,
	2020	2019
Expected term (in years)	6.05	5.50 - 6.16
Stock volatility	72.01%	70.81%
Risk-free interest rate	1.37%	2.26% - 2.56%
Dividend rate	—	—

Schedule of Stock Option Activity

The following table summarizes stock option activity under the 2014 and 2018 Plans (in thousands, except share and per share data):



	Number of Options		Weighted-Average Exercise Price Per Share		Aggregate Intrinsic Value
Outstanding at December 31, 2019	2,847,101		$	13.22
Options granted	5,000		29.03
Options exercised	(181,456	)	1.90		$	5,114	⁽¹⁾
Options forfeited	(9,261	)	22.62
Outstanding at March 31, 2020	2,661,384		$	13.99	$	33,358	⁽²⁾

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(1)	Represents the total difference between the Company’s closing stock price at the time of exercise and the stock option exercise price, multiplied by the number of options exercised.


(2)	Represents the total difference between the Company’s closing stock price on the last trading day of the first quarter of 2020 and the stock option exercise price, multiplied by the number of in-the-money options as of March 31, 2020. The amount of intrinsic value will change based on the fair market value of the Company’s stock.

Schedule of Restricted Shares Awards Activity

The following table summarizes restricted shares awards activity:



	Number of Restricted Shares Awards		Weighted-Average Fair Value Per Share at Grant Date
Outstanding at December 31, 2019	586,166		$	23.59
Restricted shares awards granted	178,500		24.26
Restricted shares awards vested	(70,880	)	18.83
Restricted shares awards forfeited	(6,625	)	21.12
Outstanding at March 31, 2020	687,161		$	24.21

Schedule of Restricted Stock Units Activity

The following table summarizes restricted stock units activity:



	Number of Restricted Stock Units		Weighted-Average Fair Value Per Share at Grant Date
Outstanding at December 31, 2019	248,104		$	21.48
Restricted stock units granted	8,000		29.03
Restricted stock units vested	(46,336	)	$	14.19
Outstanding at March 31, 2020	209,768		$	23.37