Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Stock-based Compensation Expense

Stock-based compensation expense included in the consolidated statements of operations was as follows (in thousands):

	Year Ended December 31,
	2022		2021		2020
Infrastructure and trust & safety	$	56,197	$	35,255	$	7,396
Research and development	398,899		219,851		39,402
General and administrative	109,607		72,929		25,939
Sales and marketing	24,795		13,907		6,421
Total stock-based compensation	$	589,498	$	341,942	$	79,158

Schedule of Valuation Assumptions

The following table presents the assumptions used in estimating the grant date fair value of our stock options, which were last granted during the year ended December 31, 2020:

	Year Ended December 31,
	2020
Risk-free interest rate	0.5% -1.8%
Expected volatility	35.4% - 39.8%
Dividend yield	—
Expected terms (in years)	7
Fair value of the underlying Class A common stock (per share)	$4.61 - $21.06

The following table presents the assumptions used in estimating the grant date fair value of purchase rights granted under the 2020 ESPP for the offerings made in the respective years including reset and rollover:

	Year Ended December 31,
	2022			2021
Risk-free interest rate	0.71%	-	3.35%	0.06%	-	0.25%
Expected volatility	54.16%	-	81.51%	46.97%	-	56.91%
Dividend yield	—%			—%
Expected terms (in years)	0.50	-	2.01	0.44	-	2.00

Schedule of Summarizes the Company's Stock Option Activity

The following table summarizes the Company’s stock option activity (in thousands, except per option data and remaining contractual term):

	Options Outstanding
	Number of Shares Subject to Options	Weighted- Average Exercise Price (per Option)		Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value
Balances as of December 31, 2019	99,682	$	1.66
Granted	23,269	$	4.73
Cancelled, forfeited, and expired	(3,859)	$	2.39
Exercised	(20,590)	$	0.74
Balances as of December 31, 2020	98,502	$	2.55	7.76	$	3,838,994
Granted	—	$	—
Cancelled, forfeited, and expired	(1,862)	$	3.95
Exercised	(33,373)	$	1.95
Balances as of December 31, 2021	63,267	$	2.82	6.97	$	6,348,395
Granted	—	—
Cancelled, forfeited, and expired	(2,061)	$	4.06
Exercised	(9,615)	$	2.37
Balances as of December 31, 2022	51,591	$	2.85	6.00	$	1,321,183
Exercisable as of December 31, 2022	40,018	$	2.42	5.65	$	1,042,119
Vested and expected to vest at December 31, 2022	51,591	$	2.85	6.00	$	1,321,183

Schedule of Company's Restricted Stock Units and Unregistered Restricted Stock Awards Activity

The following table summarizes the Company’s RSU and RSA activity (in thousands, except per share data):

	Restricted Stock Units			Unregistered Restricted Stock Awards
	Number of Shares	Weighted- Average Grant Date Value per Share		Number of Shares	Weighted- Average Grant Date Value per Share
Unvested as of December 31, 2019	30	$	3.35	—	—
Granted	3,061	$	31.55	388	$	37.75
Vested	(30)	$	3.35	—	—
Unvested as of December 31, 2020	3,061	$	31.55	388	$	37.75
Granted	13,382	$	78.92	209	$	81.67
Vested	(1,376)	$	38.46	(129)	$	37.75
Cancelled	(383)	$	52.78	—	—
Unvested as of December 31, 2021	14,684	$	68.03	468	$	57.37
Granted	25,540	$	41.09	298	$	46.00
Vested	(8,169)	$	57.65	(266)	$	53.67
Cancelled	(1,733)	$	57.58	—	—
Unvested as of December 31, 2022	30,322	$	48.73	500	$	52.55

Summary of Measured Based on an Average of Our Stock Price

The CEO Long-Term Performance Award is divided into seven performance periods that are eligible to vest based on the achievement of various Company Stock Price Hurdles, measured based on an average of our stock price over a consecutive 90-day trading period applicable to the performance period as set forth below. In addition, Mr. Baszucki must remain employed as our CEO through the date a Company Stock Price Hurdle is achieved in order to earn the RSUs that relate to the applicable Company Stock Price Hurdle.

	Company Stock Price Hurdle		Number of RSUs Eligible to Vest	Performance Period Commencement Dates as Measured from the Effective Date
1	$	165.00	750,000	2 years
2	$	200.00	750,000	3 years
3	$	235.00	2,000,000	4 years
4	$	270.00	2,000,000	5 years
5	$	305.00	2,000,000	5 years
6	$	340.00	2,000,000	5 years
7	$	375.00	2,000,000	5 years