Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2022

Stock Based Compensation

Summary of outstanding and exercisable stock options

				Weighted-
		Weighted-		Average
		Average		Remaining
		Exercise		Contractual Term
	Options	Price		(in Years)
Outstanding as of December 31, 2021	778,835	$	18.02	5.59
Granted	44,905		14.95	6.47
Exercised	(18,186)		4.31
Expired	(1,320)		21.75
Forfeited	(10,457)		28.03
Outstanding as of September 30, 2022	793,777	$	18.02	4.92
Options vested and exercisable as of September 30, 2022	684,927	$	17.12	4.71
Options vested and expected to vest as of September 30, 2022	793,777	$	18.02	4.92

Schedule of vesting for unvested options

		Weighted-Average
	Options	Grant-Date Fair Value
Unvested as of December 31, 2021	127,357	$	17.42
Granted	44,905		8.99
Vested	(52,955)		17.43
Forfeited	(10,457)		16.52
Unvested as of September 30, 2022	108,850	$	14.03

Schedule of valuation assumptions

	Nine Months Ended
	September 30,
	2022		2021
Expected term in years (1)	4.3		4.3
Volatility (2)	77.6	%	78.6	%
Risk-free interest rate (3)	2.9	%	0.7	%
Dividend yield (4)	—	%	—	%

(1) The Company estimated the expected term based on the average of the weighted-average vesting period and the contractual term of the stock option awards by utilizing the “simplified method”, as the Company does not have sufficient available historical data to estimate the expected term of these stock option awards.

(2) Volatility was based on a weighting of the Company’s historical volatility and its peer group, which is comprised of companies with similar industry, size and financial leverage.

(3) The risk-free interest rate was determined by using the United States Treasury rate for the period consistent with the expected option term described above.

(4) The Company’s expected annual dividend yield was zero based on current practice. 

Summary of changes in outstanding restricted stock units

				Weighted-
				Average
		Weighted-		Remaining
		Average		Amortization
		Grant-Date		Period
	Shares	Fair Value		(in Years)
Outstanding as of December 31, 2021	261,982	$	13.19
Granted	27,007		14.95
Vested	(31,258)		29.62
Forfeited	(18,247)		10.89
Outstanding as of September 30, 2022	239,484	$	11.42	1.26