STOCK-BASED AWARDS

6 Months Ended

Jun. 30, 2024

Share-Based Payment Arrangement [Abstract]

Stock Options

A summary of stock option activity for the six months ended June 30, 2024 was as follows:


	Outstanding Options
	Number of Options	Weighted Average Exercise Price		Weighted-Average Remaining Contractual Term	Intrinsic Value (in thousands)
Balance as of December 31, 2023	32,911,135	$	1.99	5.5	$	91,785
Options granted	232,177	3.99
Options exercised	(2,098,557)	1.10
Options canceled	(757,507)	7.29
Balance as of June 30, 2024	30,287,248	$	1.94	4.91	$	43,217
Options vested and exercisable as of June 30, 2024	26,461,672	$	1.28	4.71	$	42,821

As of June 30, 2024, unrecognized stock-based compensation cost related to outstanding unvested stock options that are expected to vest was $10.5 million, which is expected to be recognized over a weighted-average period of 2.8 years.

Restricted Stock Units (“RSUs”)

A summary of RSUs activity for the six months ended June 30, 2024 was as follows:


	Restricted Stock Units
	Time-Based Shares	Performance-Based Shares	Total Shares	Weighted-Average Grant-Date Fair Value
Balance as of December 31, 2023	54,699,739	9,305,825	64,005,564	$	10.90
Granted	77,029,707	7,728,436	84,758,143	2.69
Vested	(13,155,545)	(1,263,684)	(14,419,229)	11.83
Cancelled/Forfeited	(4,220,018)	(3,719,513)	(7,939,531)	8.08
Balance as of June 30, 2024	114,353,883	12,051,064	126,404,947	$	5.47

As of June 30, 2024, unrecognized stock-based compensation cost related to outstanding unvested time-based RSUs that are expected to vest was $471.2 million, which is expected to be recognized over a weighted-average period of 1.8 years.

In 2021, the Company granted performance-based RSUs to the CEO and they are subject to performance and market conditions. The performance condition was satisfied upon the closing of the Merger. The fair value of these performance-based RSUs was measured on the grant date, March 27, 2021, using a Monte Carlo simulation model, with the following assumptions:


Weighted average volatility	60.0	%
Expected term (in years)	5.0
Risk-free interest rate	0.9	%
Expected dividends	—	%

The Company recognizes compensation expense using a graded vesting attribution method over the derived service period for the CEO performance-based awards. Stock-based compensation expense is recognized when the relevant performance condition is considered probable of achievement for the performance-based award. During the year ended December 31, 2022, the market condition was met for the CEO performance-based awards for four of the five tranches and certified by the Board of Directors, representing an aggregate of 13,934,271 performance RSUs. The unamortized expense of $8.2 million as of December 31, 2022 for the fifth tranche, representing 2,090,140 RSUs, was fully recognized during the year ended December 31, 2023. The Company withheld approximately 0.5 million and 1.0 million shares of common stock, respectively, for the three and six months ended June 30, 2024, and 0.4 million and 0.9 million shares of common stock, respectively, for the same periods in the prior year, by net settlement to meet the related tax withholding requirements related to the CEO time-based and performance-based RSUs.

The Company granted performance-based RSUs to certain employees and they are subject to (i) corporate performance conditions and/or individual performance and (ii) a service condition which will be met generally over 3 years. The number of awards granted represents 100% of the target goal. Under the terms of the awards, the recipient may earn between 0% to 150% of the original number of grants based on actual achievement of corporate performance goals and/or individual performance. Stock-based compensation expense is recognized when the relevant performance condition is considered probable of achievement for the performance-based award. The Company recorded stock-based compensation expenses of $3.3 million and $8.0 million, respectively, during the three and six months ended June 30, 2024, and $0.7 million for the same periods in the prior year, related to these performance-based RSUs. As of June 30, 2024, the unamortized expense for the performance-based RSUs was $24.7 million, which will be recognized over a weighted-average period of 1.4 years contingent upon realization of the corporate performance conditions.

Employee Stock Purchase Plan (“ESPP”)

The ESPP authorizes the issuance of shares of common stock pursuant to purchase rights granted to employees. The plan provides for 24-month offering periods beginning in December and June of each year, and each offering period will consist of four six-month purchase periods. The purchase price for each share purchased during an offering period will be the lesser of 85% of the fair market value of the share on the purchase date or 85% of the fair market value of the share on the offering date. As of June 30, 2024, unrecognized stock-based compensation cost related to the ESPP was $32.4 million which is expected to be recognized over a weighted-average period of 1.9 years.

Stock-based Compensation Expense

Total employee and nonemployee stock-based compensation expense for the three and six months ended June 30, 2024 and 2023, was classified in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Cost of revenue	$	899	$	765	$	1,811	$	1,339
Research and development	33,526		37,410		71,059		65,393
Selling, general and administrative	24,068		33,201		49,319		59,906
Restructuring charges	(1,480)		—		(1,480)		(1,443)
Total	$	57,013	$	71,376	$	120,709	$	125,195

The Company capitalized stock-based compensation expenses of $8.9 million and $19.4 million, respectively, for the three and six months ended June 30, 2024, and $12.3 million and $20.4 million, respectively, for the same periods in the prior year, primarily as part of the cost of inventory.