Stockholders' Equity

3 Months Ended

Mar. 31, 2022

Equity [Abstract]

Stockholders' Equity

Stockholders’ Equity

Issuances of Common Stock

A summary of the status of stock option activity for the three months ended March 31, 2022 is as follows (in thousands, except price data):

	Shares	Weighted-average exercise price per share
Outstanding at December 31, 2021	722	$	62.71
Granted	135	103.06
Exercised	(40)	36.00
Forfeited	(14)	110.68
Outstanding at March 31, 2022	803	$	69.98

A summary of the status of RSU activity for the three months ended March 31, 2022 is as follows (in thousands, except price data):

	Shares	Weighted-average grant date fair value
Non-vested December 31, 2021	587	$	95.81
Granted	313	103.60
Vested	(156)	77.83
Forfeited	(27)	100.98
Non-vested at March 31, 2022	717	$	102.94

During the three months ended March 31, 2022, the Company issued 26,426 shares of common stock in connection with the Company’s employee stock purchase plan (the “ESPP”).

Stock-Based Compensation

The expense related to the Company’s stock-based compensation plans included in the accompanying Consolidated Statements of Income was as follows (in thousands):

	Three Months Ended March 31,
	2022		2021
Cost of sales	$	649	$	516
Research and development	1,124		1,034
Sales and marketing	1,760		1,404
General and administrative	3,529		2,874
Acquisition and integration costs	370		—
Total stock-based compensation expense	$	7,432	$	5,828

As of March 31, 2022, total unrecognized compensation expense was $66.7 million, which is expected to be recognized over a weighted-average period of approximately 2.6 years.

The estimated fair value of each stock option was determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions for the option grants.

	Three Months Ended March 31,
	2022		2021
Risk-free interest rate	1.63	%	0.42	%
Expected option life (in years)	4.91		5.01
Volatility rate	58	%	53	%
Dividend rate	0	%	0	%
Weighted-average grant date fair value	$51.79		$115.78

The fair value of RSUs is determined based on the closing market price of the Company’s common stock on the grant date. The weighted-average fair value of RSUs granted during the three months ended March 31, 2022 and 2021 was $103.60 and $238.20, respectively.

Compensation expense capitalized to inventory and compensation expense related to the ESPP were not material for the three months ended March 31, 2022 or 2021.