Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities:
Net loss	$ (182,587)	$ (158,454)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	7,582	2,834
Share-based compensation expense	135,712	115,662
Non-cash postcombination compensation expense	32,430	0
Non-cash operating leases expense	1,870	1,689
Amortization of premium (accretion of discount) on short-term investments	(5,525)	449
Impairment of other financial instruments	0	11,616
Other	1,068	445
Changes in operating assets and liabilities:
Accounts receivable	(1,108)	271
Settlements receivable	(1,477)	916
Network incentives receivable	8,086	3,336
Prepaid expenses and other assets	7,760	(11,596)
Accounts payable	(4,350)	(891)
Revenue share payable	4,289	(5,084)
Accrued expenses and other liabilities	3,331	13,144
Operating lease liabilities	(2,499)	(2,231)
Net cash provided by (used in) operating activities	4,582	(27,894)
Cash flows from investing activities:
Purchases of property and equipment	(722)	(1,700)
Capitalization of internal-use software	(9,488)	0
Business combination, net of cash acquired	(135,630)	0
Purchases of patents	0	(600)
Purchases of short-term investments	(972,430)	(21,660)
Sales of marketable securities	637,913	0
Maturities of short-term investments	437,034	24,900
Realized gain/loss on investments	(73)	0
Net cash (used in) provided by investing activities	(43,396)	940
Cash flows from financing activities:
Proceeds from exercise of stock options, including early exercised stock options, net of repurchase of early exercised unvested options	4,081	5,733
Payment on acquisition-related contingent consideration	(53,067)	0
Proceeds from shares issued in connection with employee stock purchase plan	1,775	2,775
Taxes paid related to net share settlement of restricted stock units	(18,553)	(11,576)
Repurchase of common stock	(131,519)	(12,702)
Net cash used in financing activities	(197,283)	(15,770)
Net decrease in cash, cash equivalents, and restricted cash	(236,097)	(42,724)
Cash, cash equivalents, and restricted cash- Beginning of period	1,191,646	1,255,381
Cash, cash equivalents, and restricted cash - End of period	955,549	1,212,657
Reconciliation of cash, cash equivalents, and restricted cash
Cash and cash equivalents	947,749	1,204,857
Restricted cash	7,800	7,800
Total cash, cash equivalents, and restricted cash	955,549	1,212,657
Supplemental disclosures of cash flow information:
Cash paid for operating lease liabilities	3,158	3,071
Cash paid for income taxes	915	84
Supplemental disclosures of non-cash investing and financing activities:
Purchase of property and equipment accrued and not yet paid	77	715
Share-based compensation capitalized to internal-use software	3,530	0
Repurchase of common stock, including excise tax, accrued and not yet paid	$ 2,417	$ 1,153