Our restricted stock units (“RSUs”) and restricted stock awards (“RSAs”) vest based on the terms in the grant agreements and generally vest ratably over one to four years from the vesting commencement date. The following table summarizes the RSU and RSA activity for the nine months ended September 30, 2024:


	Service- based RSUs	RSAs	Market and Performance- based RSUs	Total RSUs and RSAs	Weighted- average grant date fair value
Unvested as of December 31, 2023	25,406,057	87,030	1,393,446	26,886,533	$	29.17
Granted	4,815,577	153,648	43,353	5,012,578	$	49.80
Vested	(15,381,261)	(43,516)	(1,351,867)	(16,776,644)	$	29.41
Canceled/Forfeited	(1,262,437)	—	(30,789)	(1,293,226)	$	29.92
Unvested as of September 30, 2024	13,577,936	197,162	54,143	13,829,241	$	36.29

As of September 30, 2024, we had RSUs and RSAs outstanding for 13,829,241 common shares, of which 13,193,757 relate to Class A common stock and 635,484 relate to Class B common stock. Total unrecognized stock-based compensation expense related to RSUs and RSAs was $328.1 million as of September 30, 2024 and is expected to be recognized over a weighted-average period of 1.55 years.

Stock options vest based on terms in the stock option agreement and generally vest over five years quarterly or four years with 25% of the award vesting one year from the vesting commencement date then ratably over the following three years. The following table summarizes the stock option activity during the nine months ended September 30, 2024:


	Outstanding stock options	Weighted- average exercise price		Weighted- average remaining contractual life (years)	Aggregate intrinsic value
	(in thousands, except share, per share, and year data)
Balance as of December 31, 2023	29,795,909	$	17.83	6.00	$	500,472

Exercised	(11,047,254)	5.70
Canceled/Forfeited	(89,715)	8.87
Balance as of September 30, 2024	18,658,940	$	25.06	6.17	$	798,086
Vested as of September 30, 2024	10,950,664	$	11.31	4.04	$	603
Vested and expected to vest as of September 30, 2024	18,658,940	$	25.06	6.17	$	798,086

As of September 30, 2024 we had outstanding stock options for 18,658,940 common shares, of which 14,503,023 relate to Class A common stock and 4,155,917 relate to Class B common stock. Total unrecognized stock-based compensation expense related to stock options was $119.9 million as of September 30, 2024 and is expected to be recognized over a weighted-average period of 4.18 years.

The following table summarizes the components of stock-based compensation expense recognized in the consolidated statements of operations for all periods presented:


	Three months ended September 30,				Nine months ended September 30,
	2024		2023		2024		2023
	(in thousands)
Cost of revenue	$	70	$	19	$	389	$	82
Research and development	41,343		5,157		387,801		18,407
Sales and marketing	7,451		1,249		75,116		4,335
General and administrative	25,894		2,967		253,226		9,151
Stock-based compensation expense	$	74,758	$	9,392	$	716,532	$	31,975