Stock-Based Compensation

3 Months Ended

Mar. 31, 2024

Stock-Based Compensation

Stock-Based Compensation

7. Stock-Based Compensation

Summary of Stock Option and Award Activity

The following table summarizes the stock option and award activity for the three months ended March 31, 2024:

		Options Outstanding
			Weighted-		Weighted-
	Options and		Average		Average	Aggregate
	Awards		Exercise		Remaining	Intrinsic
	Available for	Number of	Price Per		Contractual	Value
	Grant	Options	Share		Life (years)	(In thousands)
Balance—December 31, 2023	598,397	1,829,428	$	5.96	6.9	$	5,676
Authorized	632,414
RSUs granted	(854,927)
RSUs cancelled/forfeited	—
Warrants exercised	—
Options granted	—	—	$	—
Options exercised	—	(96,116)	$	3.67		$	470
Options cancelled/forfeited	—	—	$	—
Balance—March 31, 2024	375,884	1,733,312	$	6.09	6.7	$	3,405
Options exercisable—March 31, 2024		1,304,017	$	5.80	6.4	$	2,935

The total grant date fair value of options vested was $0.3 million and $1.9 million during the three months ended March 31, 2024 and 2023, respectively. There were no options granted during the three months ended March 31, 2024. The weighted-average grant date fair value of options granted during the three months ended March 31, 2023 was $3.20 per share.

As of March 31, 2024, there was $1.9 million of total unrecognized stock-based compensation expense related to unvested options which is expected to be recognized over a weighted-average period of 1.5 years. Stock-based compensation cost for options capitalized within inventory at March 31, 2024 and 2023 was not material.

2016 Employee Stock Purchase Plan

In January 2024, there was an increase of 210,804 shares reserved for issuance under the Company’s Employee Stock Purchase Plan (ESPP) pursuant to the terms of the ESPP. The Company had 1,100,966 shares available for future issuance under the Company’s ESPP as of March 31, 2024. Employees did not purchase any shares during the three months ended March 31, 2024 and 2023, respectively.

Restricted Stock Units

The following table summarizes restricted stock units (RSUs) activity for the three months ended March 31, 2024:

	RSUs Outstanding
		Weighted-
		Average
	Number of	Grant Date
	Restricted Stock	Fair Value Per
	Units	Share
Balance—December 31, 2023	905,781	$	6.59
Granted	854,927	$	8.93
Vested	(229,923)	$	6.43
Cancelled/forfeited	—	$	—
Balance—March 31, 2024	1,530,785	$	7.92

The fair value of RSUs is determined on the date of grant based on the market price of the Company’s common stock on that date.

As of March 31, 2024, there was $10.9 million of unrecognized stock-based compensation expense related to RSUs to be recognized over a weighted-average period of 2.8 years. Stock-based compensation cost related to RSUs capitalized within inventory at March 31, 2024 and 2023 was not material.