The Company has three equity incentive compensation plans: the 2006 Plan, the 2015 Plan and the 2021 Plan.

The 2006 Plan was originally adopted by the Board and approved by the Company’s stockholders in 2006. The 2006 Plan was terminated in 2015 in connection with the adoption of the 2015 Plan and as a result no new awards may be issued under the 2006 Plan. However, the 2006 Plan will continue to govern the terms and conditions of the outstanding awards previously granted under the 2006 Plan.

The 2015 Plan was originally adopted by the Board and approved by the Company’s stockholders in 2015. In July 2021, the 2015 Plan terminated immediately prior to effectiveness of the 2021 Plan with respect to the grant of future awards. However, the 2015 Plan will continue to govern the terms and conditions of the outstanding awards previously granted under the 2015 Plan.

On July 28, 2021, the 2021 Plan was adopted and approved by the Board and stockholders. The 2021 Plan provides for the grant of incentive stock options to employees and any subsidiary corporations’ employees, and for

the grant of nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units (“RSUs”), and performance awards to employees, directors, and consultants and subsidiary corporations’ employees and consultants. The number of shares of the Company’s common stock originally available for issuance under the 2021 Plan was equal to 2,420,135 shares of common stock plus any shares subject to awards granted under the 2015 Plan and the 2006 Plan that, after the effectiveness of the 2021 Plan, expire or otherwise terminate without having been exercised in full, are tendered to or withheld by the Company for payment of an exercise price or for tax withholding obligations, or are forfeited to or repurchased by the Company due to failure to vest, with the maximum number of shares to be added to the 2021 Plan from the 2015 Plan and 2006 Plan equal to 4,569,530 shares of common stock.

The number of common shares reserved for issuance under the 2021 Plan will be increased automatically on the first day of each fiscal year beginning with the 2022 fiscal year and ending on the ten year anniversary of the date the Board approved the 2021 Plan, by a number equal to the least of: (i) 7,260,406 shares of our common stock; (ii) 4% of the outstanding shares of our common stock on the last day of the immediately preceding fiscal year; or (iii) such lesser number of shares of our common stock as the administrator may determine. The 2021 Plan is administered by the Board. On January 1, 2024 and 2023, the number of shares available under the 2021 Plan increased by 1,445,580 and 1,130,735 shares of common stock, respectively, pursuant to this feature. As of September 30, 2024, the number of shares of the Company’s common stock available for future issuance under the 2021 Plan was equal to 599,452 shares of common stock.

On July 28, 2021, the Board and stockholders adopted and approved the 2021 ESPP. As of September 30, 2024, the number of shares of the Company’s common stock available for future issuance under the 2021 ESPP was equal to 538,942 shares of common stock.

The 2021 ESPP provides eligible employees of the Company and its subsidiaries with the opportunity to purchase shares of the Company’s common stock at a purchase price equal to 85% of the common stock’s fair market value on the first trading day or last trading day of each purchase period, whichever is lower. The 2021 ESPP provides for two six-month purchase periods every twelve months: May 1 through October 31 and November 1 through April 30. The initial purchase period began on November 1, 2021.

The number of common shares reserved for issuance under the 2021 ESPP will be increased automatically on the first day of each fiscal year beginning with the 2022 fiscal year, by a number equal to the least of: (i) 1,452,081 shares; (ii) 1% of the outstanding shares of our common stock on the last day of the immediately preceding fiscal year; or (iii) such other amount as the administrator may determine. The 2021 ESPP is administered by the Board. No additional shares were reserved for issuance on January 1, 2024 and 2023 pursuant to this feature.

The purpose of the 2021 Plan and 2021 ESPP is to provide a means by which eligible recipients of stock awards may be given an opportunity to benefit from increases in the value of the common stock in order to retain or procure the services of the employees, members of the Board and consultants and provide them with an incentive to promote the Company’s success and accomplish corporate goals.

Stock option awards are granted with an exercise price of no less than 100% of estimated fair market value on the date of grant. Time based awards generally vest over four years as follows, subject to the optionee’s continuing service: (i) one fourth of the total number of shares vest and become exercisable on the one-year anniversary and then 1/48th of the total number of shares subject to the option vest and become exercisable on each monthly anniversary thereafter for the remaining three years, or (ii) 1/48th of the total number of shares subject to the option vest and become exercisable each month over four years.

A summary of the stock option activities related to the Equity Plans for the nine months ended September 30, 2024 is presented below:


	Number of Options			Weighted Average Exercise Price		Weighted Avg Remaining Contractual Life (Years)
Options outstanding as of December 31, 2023		6,777,404		$	13.02		6.51
Granted		1,147,452			53.00
Exercised		(1,809,836	)		9.44
Forfeited		(82,972	)		17.34
Expired		(10,251	)		4.65
Options outstanding as of September 30, 2024		6,021,797			21.66		7.13
Exercisable as of September 30, 2024		3,390,946		$	15.10		5.98

As of September 30, 2024 and December 31, 2023 the intrinsic value of options vested was $117.0 million and $121.3 million, respectively, and of all options outstanding was $172.4 million and $185.0 million, respectively. During the nine months ended September 30, 2024 and 2023, the total cash received from the exercise of stock options was $17.1 million and $5.4 million, respectively. The total fair value less strike price of these options was $75.1 million and $8.4 million, respectively.

A summary of non-vested restricted stock unit activities for the nine months ended September 30, 2024 is as follows:


				Weighted
				Average
	Number of			Grant Date
	Shares			Fair Value

Unvested at December 31, 2023		650,357		$	15.80
Granted		263,481			53.28
Vested		(298,094	)		19.56
Forfeited		(27,158	)		17.47
Unvested at September 30, 2024		588,586		$	30.60

Stock-based compensation expense was classified in the accompanying condensed consolidated statements of operations and comprehensive income (loss) as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	1,559	$	1,035	$	4,060	$	2,857
Selling, general and administrative		4,446		2,731		11,856		7,642
Cost of sales		547		305		1,437		822
	$	6,552	$	4,071	$	17,353	$	11,321

As of September 30, 2024 and December 31, 2023, there were 2,630,851 and 2,539,445 unvested options, respectively. As of September 30, 2024 and December 31, 2023, total unrecognized expense related to unvested stock options was approximately $49.7 million and $22.7 million, respectively. Both amounts are expected to be recognized over a weighted average period of approximately 2.5 and 2.4 years, respectively.

As of September 30, 2024, and December 31, 2023, total unrecognized expense related to non-vested restricted stock units was approximately $17.0 million and $8.3 million, respectively. The unrecognized compensation cost is expected to be recognized over a weighted average period of 2.4 years and 2.3 years, respectively.

The following table presents the range and weighted-average assumptions, used in the Black-Scholes option pricing model to determine the fair value of stock options:


	Nine Months Ended September 30,
	2024		2023
	Range	Weighted Average	Range	Weighted Average
Expected volatility	67.8% to 72.3%	70.4%	64.9% to 67.7%	65.3%
Risk-free interest rate	3.5% to 4.7%	4.1%	3.4% to 4.6%	4.1%
Expected life (in years)	6.0 to 6.1 years	6.0 years	5.5 to 6.1 years	6.1 years
Expected dividend yield	0.0%	0.0%	0.0%	0.0%
Grant date fair value	$36.89 to $60.65	$53.45	$12.91 to $32.45	$16.89

Each share of common stock is entitled to one vote. Common stock reserved for future issuance consisted of the following:


	September 30, 2024		December 31, 2023
Stock options issued and outstanding under the Equity Plans		6,021,797		6,777,404
Shares available for future issuance under the 2021 Plan		599,452		358,610
Restricted stock units issued under the 2021 Plan		588,586		650,357
Shares available for future issuance under 2021 ESPP		538,942		577,847
Total shares of common stock reserved		7,748,777		8,364,218