As of September 30, 2026, the Company had 18,238,095 shares reserved including 1,616,712 shares available for future issuance, pursuant to the Beam Therapeutics Inc. 2019 Equity Incentive Plan.

Stock-based compensation expense recorded as research and development and general and administrative expenses in the condensed consolidated statements of operations and other comprehensive loss is as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2026		2025		2026		2025
Research and development	$	10,798	$	13,840	$	33,100	$	44,405
General and administrative		7,757		8,907		23,777		29,391
Total stock-based compensation expense	$	18,555	$	22,747	$	56,877	$	73,796

The following table provides a summary of stock option activity under the Company’s equity award plans:


	Number of options			Weighted average exercise price
Outstanding at December 31, 2025		11,316,549		$	35.68
Granted		2,685,956			28.33
Exercised		(686,283	)		15.31
Forfeited		(583,603	)		42.69
Outstanding at September 30, 2026		12,732,619			34.92
Exercisable as of September 30, 2026		8,206,874		$	39.19

The weighted-average grant date fair value per share of stock options granted in the nine months ended September 30, 2026 was $20.20. As of September 30, 2026, there was $85.0 million of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted-average remaining vesting period of approximately 2.6 years.

The Company issues shares of restricted common stock, including both restricted stock units and restricted stock awards. Restricted common stock issued generally vests over a period of two to four years.

The following table summarizes the Company’s restricted stock activity:


	Shares			Weighted- average grant date fair value
Unvested as of December 31, 2025		2,543,852		$	27.16
Issued		2,380,428			24.78
Vested		(866,999	)		31.30
Forfeited		(231,437	)		24.53
Unvested as of September 30, 2026		3,825,844		$	24.90

At September 30, 2026, there was approximately $81.6 million of unrecognized stock-based compensation expense related to restricted stock that is expected to vest. These costs are expected to be recognized over a weighted-average remaining vesting period of approximately 2.7 years.

The Company issued 140,991 and 174,708 shares under the Beam Therapeutics Inc. 2019 Employee Stock Purchase Plan, or ESPP, during the nine months ended September 30, 2026 and 2025, respectively. As of September 30, 2026, the Company had 4,466,826 shares available for issuance under the ESPP.

Stock-based compensation recognized under the ESPP for the three and nine months ended September 30, 2026 was $0.3 million and $1.1 million, respectively. The Company recognized stock-based compensation under the ESPP of $0.4 million and $1.2 million for the three and nine months ended September 30, 2025, respectively.