Stock-based Compensation (Tables)

3 Months Ended

6 Months Ended

Jun. 30, 2024

Stock-based compensation expense during the three and six months ended June 30, 2024 and 2023 was as follows (in thousands):


	Three Months Ended June 30,				Six Months Ended June 30,
	2024		2023		2024		2023
Stock-based compensation expense by type of award:
Stock options	$	10,027	$	7,431	$	16,913	$	16,029
Restricted stock units	9,918		3,542		18,543		6,194
Performance-based restricted stock units	4,459		—		8,850		—
Total stock-based compensation expense	$	24,404	$	10,973	$	44,306	$	22,223
Effect of stock-based compensation expense by line item:
Research and development	$	5,582	$	5,184	$	11,489	$	10,570
Selling, general and administrative	18,822		5,789		32,817		11,653
Total stock-based compensation expense included in net loss	$	24,404	$	10,973	$	44,306	$	22,223

The following table summarizes stock option activity during the six months ended June 30, 2024:


	Shares	Weighted average exercise price
Outstanding at December 31, 2023	2,355,779	$	79.94
Options granted	148,970	232.88
Options exercised	(671,947)	73.91
Options cancelled	(59,995)	118.98
Outstanding at June 30, 2024	1,772,807	$	93.76
Exercisable at June 30, 2024	1,323,994	$	79.14

The following table summarizes RSU activity, excluding performance-based RSUs, during the six months ended June 30, 2024:


	Shares	Weighted average grant date fair value
Outstanding at December 31, 2023	376,117	$	241.45
RSUs granted	248,517	231.96
RSUs vested	(63,825)	289.45
RSUs forfeited	(51,862)	243.28
Outstanding at June 30, 2024	508,947	$	230.61

The following table summarizes PSU activity during the six months ended June 30, 2024:


	PSUs	Eligible to Earn PSUs	Weighted average grant date fair value
Outstanding PSUs at December 31, 2023	50,000	150,000	$	146.37
PSUs granted	51,202	102,404	388.02
PSUs attained	—	—	—
PSUs forfeited	(8,442)	(16,884)	388.02
Outstanding at June 30, 2024	92,760	235,520	$	257.77