Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash flows from operating activities
Net income (loss) before attribution to noncontrolling interests		$ (108,665)	$ 135,443	$ 5,579
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Change in fair value of financial instruments	[1]	168,878	(228)	29,049
Stock-based compensation		125,945	73,186	11,513
Gain on loan servicing arrangement, net		(28,739)	(6,916)	(1,530)
Depreciation and amortization		13,513	7,541	2,278
Incentive share expense		0	0	787
Non-cash interest expense		3,047	1,983	73
Net changes in operating assets and liabilities:
Purchase of loans held-for-sale		(7,807,429)	(8,932,604)	(2,657,075)
Proceeds from sale of loans held-for-sale		6,828,617	8,826,045	2,588,552
Principal payments received for loans held-for-sale		152,018	8,659	18,218
Other assets		4,173	(62,042)	(13,186)
Operating lease liability and right-of-use asset		10,204	3,126	251
Accounts payable		11,878	(7,513)	7,033
Payable to investors		(16,821)	62,097	19,446
Accrued expenses and other liabilities		(31,300)	59,576	4,709
Net cash provided by (used in) operating activities		(674,681)	168,353	15,697
Cash flows from investing activities
Principal payments received for loans held by consolidated securitizations		0	0	24,018
Purchase of loans held-for-investment		(149,298)	(159,398)	(9,655)
Proceeds from sale of loans held-for-investment		14,289	51,403	97,340
Principal payments received for loans held-for-investment		43,311	24,532	15,758
Principal payments received for notes receivable and repayments of residual certificates		6,736	11,458	14,665
Purchase of non-marketable equity securities		(1,250)	(40,000)	0
Purchase of notes receivable and residual certificates		0	0	(4)
Purchase of property and equipment		(8,825)	(8,427)	(1,355)
Capitalized software costs		(14,088)	(6,688)	(4,250)
Purchase of certificates of deposit		(5,000)	0	0
Acquisition, net of cash acquired		0	(16,757)	0
Net cash provided by (used in) investing activities		(114,125)	(143,877)	136,517
Cash flows from financing activities
Proceeds from initial public offering, net of underwriting discounts and offering costs		0	0	159,488
Proceeds from secondary offering, net of underwriting discounts, commissions, and offering costs		0	263,931	0
Proceeds from borrowings		688,813	718,422	92,057
Payment of debt issuance costs		0	(15,727)	0
Purchase of capped calls		0	(58,523)	0
Taxes paid related to net share settlement of equity awards		(16)	(236)	0
Payments made on securitization notes and certificates	[2]	0	0	(26,126)
Repayments of borrowings		(400,898)	(71,316)	(148,113)
Distributions made to noncontrolling interests		0	0	(622)
Proceeds from exercise of convertible preferred stock warrants		0	0	6
Proceeds from issuance of common stock under employee stock purchase plan		7,662	4,145	0
Proceeds from exercise of stock options		12,354	14,736	2,362
Repurchases of common stock		(177,883)	0
Net cash provided by financing activities		130,032	855,432	79,052
Change in cash and restricted cash		(658,774)	879,908	231,266
Cash and restricted cash at beginning of year		1,191,241	311,333	80,067
Cash and restricted cash at end of year		532,467	1,191,241	311,333
Supplemental disclosures of cash flow information
Cash paid for interest		12,473	3,274	8,028
Cash paid for income taxes		328	2,300	0
Cash paid for amounts included in the measurement of lease liabilities		11,084	4,553	4,158
Supplemental disclosures of non-cash investing and financing activities
Capitalized stock-based compensation expense		5,960	3,141	492
Residual certificates retained under unconsolidated securitization		4,680	0	0
Reclassification of common stock warrant liability related to cashless exercise		0	0	2,971
Reclassification of preferred stock warrant liability related to cash exercise		0	0	12,177
Reclassification of common stock warrant liability to equity upon termination of repurchase option		0	0	2,945
Issuance of common stock in connection with acquisition		0	80,256	0
Cash and Restricted Cash
Cash		422,411	986,608
Restricted cash		110,056	204,633
Total cash and restricted cash		$ 532,467	$ 1,191,241	$ 311,333

[1] Includes $(4,238) from related parties for the year ended December 31, 2020. There were no related party balances for the year ended December 31, 2021 and 2022.

[2] Includes $1,034 paid to related parties for the year ended December 31, 2020. There were no related party balances for the year ended December 31, 2021 and 2022.