A summary of stock option activity as of June 30, 2026 is as follows:


(In thousands, except prices and years)	Number of options	Weighted- average exercise price		Weighted- average remaining contractual life (years)	Aggregate intrinsic value
Options outstanding at January 1, 2026	859	$	18.38	3.77	$	135,938
Granted (1)	—	—
Exercised	(223)	10.53

Forfeited and expired (2)	—	—
Options outstanding at June 30, 2026	636	$	21.09	3.68	$	60,408
Options exercisable at June 30, 2026	636	$	21.09	3.68	$	60,408


(In thousands, except prices)	Restricted stock units	Weighted- average grant date fair value per share
Outstanding at January 1, 2026	1,406	$	242.94
Granted	1,941	111.19
Released	(379)	182.37
Forfeited	(151)	238.45
Outstanding at June 30, 2026	2,817	$	160.55

As of June 30, 2026, there was no unrecognized stock-based compensation expense related to stock options granted under the plans. The amount of unrecognized stock-based compensation expense for RSUs as of June 30, 2026 was $412,023 with a weighted-average period of approximately three years.

There were 9,307 shares available for issuance under the Company’s 2021 Incentive Award Plan and 1,604 shares available for issuance under the Company’s 2021 Employee Stock Purchase Plan, in each case, at June 30, 2026.

In June 2021, the Company granted performance-based RSUs to its founders (“Founder Awards”) that vest based on continued service and the achievement of specified stock price targets. As of June 30, 2026, certain performance conditions have been achieved, while others remain subject to future stock price performance. Stock-based compensation expense is recognized over the derived service period using an accelerated attribution method, subject to continued service.

In 2026, the Company modified the service condition applicable to the final two tranches of the Founder Awards held by one of its founders. The modification was accounted for as a Type III modification under ASC 718. As a result of the revised service condition, the Company reversed $8,217 of stock-based compensation expense previously recognized under the original derived service periods. The modified awards have a total compensation cost of approximately $9,960, based on the modified fair value

determined using a Monte Carlo simulation model, representing an increase of $1,743, over the original grant-date fair value. The total compensation cost will be recognized over the revised derived service periods, which extend through September 30, 2029.

As a result of the modification, the Company recognized a stock-based compensation benefit of $6,982 and $5,766 related to the Founder Awards during the three and six months ended June 30, 2026, respectively. The Company recognized stock-based compensation expense of $3,963 and $8,077 for the three and six months ended June 30, 2025, respectively. As of June 30, 2026, unrecognized stock-based compensation expense related to the Founder Awards was $12,240.

Total stock-based compensation expense was $38,210 and $72,857 for the three and six months ended June 30, 2026 and $34,592 and $65,610 for the three and six months ended June 30, 2025, respectively.

Stock-based compensation expense is included in the Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income as shown in the following table:


	Three Months Ended June 30,				Six Months Ended June 30,
(In thousands)	2026		2025		2026		2025
Cost of revenues	$	31	$	24	$	54	$	44
Research and development	26,861		20,481		49,384		38,294
Sales and marketing	2,008		1,593		3,804		3,024
General and administrative	9,310		12,494		19,615		24,248
Total	$	38,210	$	34,592	$	72,857	$	65,610

In February 2026, Duolingo’s Board of Directors authorized a share repurchase program of up to $400,000. During the three and six months ended June 30, 2026, the Company repurchased a total of 432 and 695 shares, respectively, of the Company’s Class A common stock through open market purchases at an average per share price of $102.80 and $101.15, respectively, for a total repurchase price of $44,448 and $70,278, respectively. During the three and six months ended June 30, 2026, 467 and 683 of these shares were retired, respectively. The cost of the remaining 12 shares is recorded as treasury stock in the Unaudited Condensed Consolidated Balance Sheets as of June 30, 2026. As of June 30, 2026, $329,722 of the total amount authorized to be repurchased remained available.