In February 2020, the Company adopted the 2020 Incentive Award Plan (the 2020 Plan). The 2020 Plan became effective on February 11, 2020. The 2020 Plan provides for a variety of stock-based compensation awards, including stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance bonus awards, performance stock unit awards, dividend equivalents, or other stock or cash based awards. Under the 2020 Plan, the Company generally grants stock-based awards with service-based vesting conditions only. Options and restricted stock unit awards granted typically vest over a four-year period, but may be granted with different vesting terms.

Following the effectiveness of the 2020 Plan, the Company ceased making grants under the 2014 Equity Incentive Plan (the 2014 Plan). However, the 2014 Plan continues to govern the terms and conditions of the outstanding awards granted under it. Shares of

common stock subject to awards granted under the 2014 Plan that are forfeited or lapse unexercised and that were not issued under the 2014 Plan are available for issuance under the 2020 Plan.

In February 2020, the Company adopted the 2020 Employee Stock Purchase Plan (the ESPP). Under the ESPP, employees have the ability to purchase shares of the Company’s common stock through payroll deductions at a discount during a series of offering periods of 24 months, each comprised of four six-month purchase periods. The purchase price will be the lower of 85% of the closing trading price per share of the Company’s common stock on the first day of an offering period in which an employee is enrolled or 85% of the closing trading price per share on the purchase date, which will occur on the last trading day of each purchase period.

For the three and six months ended June 30, 2026, there were 208,030 shares of common stock purchased under the ESPP. As of June 30, 2026, a total of 7,125,587 shares of common stock were available for future issuance under the ESPP. As of June 30, 2026, there was $13.7 million of unrecognized compensation cost related to the ESPP.

The following summarizes option activity under both the 2020 Plan and the 2014 Plan:


	Number of Shares underlying options			Weighted- average exercise price		Weighted- average remaining contractual term		Aggregate intrinsic value
						(in years)		(in thousands)
Balance, December 31, 2025		17,997,616		$	30.45		7.28	$	885,485
Options granted		2,293,328			105.54
Options exercised		(1,783,399	)		23.03
Options cancelled and forfeited		(145,861	)		46.51
Balance, June 30, 2026		18,361,684		$	40.42		7.27	$	2,696,546
Options vested and exercisable as of June 30, 2026		9,741,603		$	25.62		6.01	$	1,574,800

As of June 30, 2026, there was $277.2 million of unrecognized stock-based compensation expense related to unvested stock options that is expected to be recognized over a weighted-average period of 2.96 years.

Activity under the 2020 Plan with respect to the Company’s restricted stock units (RSUs) during the six months ended June 30, 2026 was as follows:


	Number of Shares			Weighted- average grant date fair value per share		Weighted- average remaining contractual term		Aggregate intrinsic value
						(in years)		(in thousands)
Balance, December 31, 2025		3,892,052		$	39.16		1.50	$	310,002
RSUs granted		2,053,995			108.68
RSUs vested		(763,757	)		33.61
RSUs forfeited		(103,850	)		53.66
Balance, June 30, 2026		5,078,440		$	67.82		1.58	$	951,090
Expected to vest as of June 30, 2026		5,078,440		$	67.82		1.58	$	951,090

The number of RSUs vested includes shares of common stock that the Company withheld to satisfy the minimum statutory tax withholding requirements. As of June 30, 2026, there was $304.3 million of total unrecognized compensation cost related to RSUs that is expected to be recognized over a weighted average period of 3.29 years.

Total stock-based compensation expense related to stock options, RSUs and the ESPP by function was as follows:


	Three Months Ended June 30,				Six Months Ended June 30,
	2026		2025		2026		2025
	(in thousands)				(in thousands)
Research and development	$	39,311	$	19,126	$	83,949	$	35,505
General and administrative		27,689		9,704		70,350		18,409
Total	$	67,000	$	28,830	$	154,299	$	53,914

During the three months ended March 31, 2026, the Company modified its equity compensation program to introduce retirement benefit provisions, which allow certain awards to continue vesting after retirement and extends the post-retirement exercise period for stock options, subject to specified age and service requirements. The Company accounted for these changes as Type I (probable-to-probable) modifications under ASC 718.

The modification resulted in incremental stock-based compensation expense of approximately $44.6 million recognized during the three months ended March 31, 2026. This amount includes $12.5 million of incremental expense associated with the modification of the awards, and $32.1 million related to the accelerated recognition of previously unrecognized stock-based compensation expense.