As of June 30, 2024, there are 17,785,881 shares of Class A common stock reserved for issuance under the 2020 Equity Incentive Plan (the 2020 Plan), 3,075,477 shares of which are available for issuance in connection with grants of future awards.

Stock option activity for the six months ended June 30, 2024 is as follows:


	Options Outstanding			Weighted-Average Exercise Price
Balance at December 31, 2023		11,945,032		$	11.89
Options granted		3,094,537			1.79
Options forfeited		(874,115	)		8.57
Balance at June 30, 2024		14,165,454		$	9.89
Vested and exercisable, June 30, 2024		7,687,908		$	8.74

In February 2024, the Company granted options to purchase an aggregate of 1,896,901 shares of the Company’s Class A common stock to certain Company executives, with vesting subject to market conditions (Market Condition Options). The granted options are further divided into 1,032,901 shares granted to the Chief Executive Officer (the CEO Award) and 864,000 shares of executive awards. The Market Condition Options become eligible to vest if the average of the closing sales prices of a share of Class A common stock over a trailing twenty trading day period within seven years from the date of grant reaches a stock price of $5.31 per share (the Market Price Milestone) for the CEO Award and $3.54 per share (a Market Price Milestone) for the executive awards, respectively.

In February 2023, the Company granted Market Condition Options to purchase an aggregate of 1,794,000 shares of the Company’s Class A common stock to certain executive officers, with vesting subject to market conditions. These Market Condition Options become eligible to vest if the average of the closing sales prices of a share of Class A common stock over a trailing twenty trading day period within seven years from the date of grant reaches a stock price of $6.89 per share (also a Market Price Milestone).

Under each of the above Market Condition Options, if the Market Price Milestone is achieved, 25% of each Market Condition Option will vest upon certification of such achievement, subject to the recipient’s continued service through the Market Price Milestone achievement date, and an additional 25% of each Market Condition Option will then vest on each of the one-, two- or three-year anniversaries of the Market Price Milestone achievement date, respectively, subject to the recipient’s continued service through the applicable anniversary date. In the event of the Company’s change in control during the seven-year performance period, the performance period will be shortened, achievement of the Market Price Milestone will be assessed based on the per share value of consideration that stockholders receive in the transaction (the change in control price), and if the Market Price Milestone is achieved on that basis, each Market Condition Option will vest in full as of immediately prior to the change in control, subject to the recipient’s continued service as of immediately prior to the change in control.

Compensation expense is recognized using an accelerated attribution method based on the derived service periods for each of the Market Condition Options. Failure to meet the Market Price Milestone for an award does not result in reversal of previously recognized expense, so long as the service is provided for the duration of the respective derived service period.

The following assumptions were used to determine the grant date fair value of $1.16 to $1.27 and $2.80 to $3.02 for the 2024 and 2023 Market Condition Options, respectively:


	2024			2023
Risk-free interest rate		4.07	%		3.94	%
Expected volatility		84.80	%		83.10	%
Expected dividend yield		—			—
Strike price	$	1.77		$	4.59

For 2024 and 2023 Market Condition Options, the grant date fair value approximates $2.3 million and $5.2 million, respectively, and was determined using a lattice-binomial option-pricing model based on a Monte Carlo simulation.

For the three and six months ended June 30, 2024, the Company recognized compensation expense of $0.6 million and $1.1 million, respectively. For the three and six months ended June 30, 2023, the Company recognized compensation expense of $1.0 million and $1.4 million, respectively.

As of June 30, 2024, $1.9 million of unrecognized compensation cost related to unvested 2024 Market Condition Options is expected to be recognized as expense over a remaining weighted-average period of 2.7 years.

As of June 30, 2024, $1.4 million of unrecognized compensation cost related to unvested 2023 Market Condition Options is expected to be recognized as expense over a remaining weighted-average period of 1.6 years.

Restricted stock unit activity for the six months ended June 30, 2024 is as follows:


	Number of Shares			Weighted-Average Grant Date Fair Value
Balance at December 31, 2023		3,680,076		$	7.49
Granted		2,813,076			1.79
Vested		(838,948	)		9.97
Forfeited		(527,831	)		4.13
Balance at June 30, 2024		5,126,373		$	4.30

A total of 2,355,024 shares of Class A common stock are reserved for issuance under the employee stock purchase plan (ESPP) as of June 30, 2024. During the six months ended June 30, 2024, 117,399 shares of Class A common stock were issued under the ESPP.

The following table summarizes the components of stock-based compensation recognized in the Company’s unaudited condensed consolidated statements of operations and comprehensive loss (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Cost of revenue	$	389	$	406	$	787	$	735
Research and development		2,115		2,733		4,254		5,281
Selling, general and administrative		5,161		6,613		10,204		12,460
Total stock-based compensation	$	7,665	$	9,752	$	15,245	$	18,476

On June 21, 2022, the Company’s Board of Directors approved an option repricing to reduce the exercise price of certain vested, outstanding, and unexercised stock options with an exercise price greater than $19.00 per share, each of which was granted under the 2020 Plan, that were held by employees who were not members of the Board of Directors or officers for purposes of Section 16 of the Securities Exchange Act of 1934, as amended (the Non-Section 16 employees) to $19.00 per share, which was the Company’s initial public offering price. The Board of Directors also approved the repricing of certain unvested, outstanding, and unexercised stock options with an exercise price greater than $19.00 per share that were held by Non-Section 16 employees to $7.40 per share, which was the closing price of the Company’s Class A common stock on the Nasdaq Global Select Market on the date of the approval of the repricing. Except for the exercise price, the amended stock options have the same terms and conditions (including vesting schedule, number of shares, and expiration date) and will continue to be governed by the terms of the 2020 Plan.

The Company recorded $0.2 million and $0.3 million of incremental compensation expense during the three and six months ended June 30, 2024, respectively. The Company recorded $0.2 million and $0.4 million of incremental compensation expense during the three and six months ended June 30, 2023, respectively. The total unrecognized incremental stock-based compensation associated with the option repricing is $0.8 million, which will be recognized over the next two years.