A summary of stock option and SAR activity for the six months ended June 30, 2026 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, 2025	16	5,868	$	48.72	4.79	$	194
Granted	—	619	$	75.51
Exercised	(6)	(169)	$	34.44
Canceled and forfeited	—	(219)	$	59.95
As of June 30, 2026	10	6,099	$	51.44	4.56	$	132
Exercisable as of June 30, 2026	10	3,557	$	41.17	3.78	$	112

The following table summarizes the activity related to our RSUs for the six months ended June 30, 2026 (in thousands, except per share amounts):


	Number of Shares	Weighted-Average Grant-Date Fair Value per Share
Unvested and outstanding as of December 31, 2025	57,654	$	65.69
Granted	35,921	$	73.57
Vested	(17,008)	$	56.31
Canceled and forfeited	(4,763)	$	68.59
Unvested and outstanding as of June 30, 2026	71,804	$	71.66

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 June 30,				Six Months Ended June 30,
	2025		2026		2025		2026
Operations and support	$	59	$	71	$	111	$	131
Sales and marketing	28		27		52		52
Research and development	284		336		548		622
General and administrative	104		122		199		224
Total	$	475	$	556	$	910	$	1,029

As of June 30, 2026, there was $4.9 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 2.93 years.

The income tax benefits recognized in the condensed consolidated statements of operations for stock-based compensation expense were not material during the three and six months ended June 30, 2025 and 2026.

In July 2025, our board of directors authorized an additional $20.0 billion for the repurchase of common stock (“Share Repurchase Program”). 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 six months ended June 30, 2025, we repurchased, and subsequently retired, 16.4 million and 42.9 million shares of common stock for $1.4 billion and $3.2 billion, respectively, excluding broker commissions and fees.

During the three and six months ended June 30, 2026, we repurchased, and subsequently retired, 6.9 million and 46.6 million shares of common stock for $510 million and $3.5 billion, respectively, excluding broker commissions and fees. As of June 30, 2026, we had approximately $15.7 billion available to repurchase shares pursuant to the Share Repurchase Program.