A summary of stock option and SAR activity for the nine months ended September 30, 2025 is as follows (in millions, except share amounts which are reflected in thousands, per share amounts, and years):


	SARs Outstanding Number of SARs	Options Outstanding Number of Shares	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Life (in years)	Aggregate Intrinsic Value
As of December 31, 2024	33	7,198	$	40.16	4.90	$	153
Granted	—	484	$	74.44
Exercised	(12)	(1,399)	$	16.34
Canceled and forfeited	(3)	(146)	$	40.81
As of September 30, 2025	18	6,137	$	48.36	4.92	$	305
Exercisable as of September 30, 2025	18	2,318	$	27.97	3.18	$	164


	Number of Shares	Weighted-Average Grant-Date Fair Value per Share
Unvested and outstanding as of December 31, 2024	66,202	$	48.49
Granted	33,047	$	76.28
Vested	(27,219)	$	46.33
Canceled and forfeited	(6,924)	$	54.66
Unvested and outstanding as of September 30, 2025	65,106	$	62.84

Stock-based compensation expense is allocated based on the cost center to which the award holder belongs. The following table summarizes total stock-based compensation expense by function (in millions):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2025		2024		2025
Operations and support	$	50	$	58	$	171	$	169
Sales and marketing	23		26		68		78
Research and development	268		278		844		826
General and administrative	97		103		294		302
Total	$	438	$	465	$	1,377	$	1,375

As of September 30, 2025, there was $3.9 billion of unamortized compensation costs related to all unvested awards. The unamortized compensation costs are expected to be recognized over a weighted-average period of approximately 2.77 years.

The income tax benefits recognized in the condensed consolidated statements of operations for stock-based compensation expense were not material during the three months ended September 30, 2024 and 2025.

The income tax benefits recognized in the condensed consolidated statements of operations for stock-based compensation expense were not material during the nine months ended September 30, 2024 and $363 million during the nine months ended September 30, 2025.

In February 2024, our board of directors authorized the repurchase of up to $7.0 billion in shares of our outstanding common stock. In July 2025, our board of directors authorized an additional $20.0 billion for the repurchase of common stock. These authorizations (collectively, the “Share Repurchase Program”) total $27.0 billion. The timing, manner, price and amount of any repurchases are determined by the discretion of management, depending on market conditions and other factors. Repurchases may be made through open market purchases and accelerated share repurchases. The exact number of shares to be repurchased by us, if any, is not guaranteed. Depending on market conditions and other factors, these repurchases may be commenced or suspended at any time or periodically without prior notice.

During the three and nine months ended September 30, 2025, we repurchased, and subsequently retired, 15.7 million and 58.6 million shares of common stock for $1.5 billion and $4.6 billion, respectively, excluding broker commissions and fees. Repurchases for the nine-month period included a $1.5 billion accelerated share repurchase (“ASR”) completed during the first quarter of 2025. As of September 30, 2025, we had approximately $21.1 billion available to repurchase shares pursuant to the Share Repurchase Program.

The Inflation Reduction Act imposed a nondeductible 1% excise tax on the net value of certain stock repurchases. During the three and nine months ended September 30, 2025, the excise tax on net share repurchases was not material.