Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Cash flows from operating activities
Net income (loss)	$ 53,601	$ (128,581)	$ (240,132)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Change in fair value of loans	(113,672)	125,002	190,320
Change in fair value of servicing assets	18,646	16,490	22,171
Change in fair value of servicing liabilities	(942)	(1,246)	(2,013)
Change in fair value of beneficial interest assets	(33,184)	5,151	21,672
Change in fair value of beneficial interest liabilities	16,579	12,568	4,817
Change in fair value of other financial instruments	(6,921)	4,130	(2,145)
Stock-based compensation	131,950	133,400	175,039
Gain on loan servicing rights, net	(28,003)	(15,449)	(13,713)
Gain on debt extinguishment	(7,246)	(33,361)	0
Depreciation and amortization	24,835	20,549	24,903
Loan premium amortization	(49,149)	(17,021)	(3,869)
Non-cash interest expense and other	8,607	3,217	3,057
Net changes in operating assets and liabilities:
Purchases of loans held-for-sale	(9,072,905)	(4,309,268)	(3,006,510)
Proceeds from sale of loans held-for-sale	8,679,462	4,101,937	2,514,627
Principal payments received for loans held-for-sale	187,660	192,889	189,746
Principal payments received for loans held by consolidated securitization	37,885	47,997	24,832
Settlements of beneficial interest liabilities, net	(21,598)	(6,700)	(596)
Proceeds from beneficial interest assets (derivatives)	4,602	0	0
Settlements of beneficial interest assets (derivatives)	(4,575)	0	0
Other assets	(10,831)	(8,690)	(8,932)
Operating lease liability and right-of-use asset	(2,084)	(807)	(6,822)
Payable to investors for beneficial interest assets	0	0	5,792
Accrued expenses and other liabilities	39,558	44,124	(3,956)
Net cash provided by (used in) operating activities	(147,725)	186,331	(111,712)
Cash flows from investing activities
Purchases and originations of loans held-for-investment	(1,033,027)	(323,096)	(157,223)
Proceeds from sale of loans held-for-investment	395,731	0	972
Principal payments received for loans held-for-investment	320,364	145,266	102,446
Principal payments received for notes receivable and repayments of residual certificates	23,051	5,917	4,328
Acquisition and settlements of beneficial interest assets (hybrid instruments)	(3,438)	(67,753)	(56,892)
Proceeds from beneficial interest assets (hybrid instruments)	142,902	11,930	0
Issuance of line of credit receivable	(7,862)	0	0
Repayments of line of credit receivable	3,515	0	0
Purchases of property and equipment	(347)	(837)	(1,527)
Capitalized software costs	(18,060)	(9,153)	(10,559)
Net cash used in investing activities	(177,171)	(237,726)	(118,455)
Cash flows from financing activities
Proceeds from borrowings	294,218	387,281	626,910
Proceeds from convertible notes issuance, net of debt issuance costs paid to lender	678,270	913,440	0
Payment of debt issuance costs to third parties	(3,150)	(3,945)	0
Repayments of borrowings	(317,097)	(357,352)	(575,937)
Payments for repurchases of convertible notes	(224,154)	(325,344)	0
Purchase of capped calls	(55,200)	(40,883)	0
Settlement of capped calls	564	580	0
Principal payments made on securitization notes	(40,592)	(55,368)	(23,320)
Payable to investors	47,486	12,385	(48,781)
Proceeds from issuance of securitization notes	0	0	165,318
Net proceeds related to stock-based award activities	25,300	29,077	21,297
Net cash provided by financing activities	405,645	559,871	165,487
Change in cash, cash equivalents and restricted cash	80,749	508,476	(64,680)
Cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash at beginning of year	976,263	467,787	532,467
Cash, cash equivalents and restricted cash at end of year	1,057,012	976,263	467,787
Supplemental disclosures of cash flow information
Cash paid for interest	43,483	43,119	36,547
Cash paid for income taxes, net	590	258	(658)
Supplemental disclosures of non-cash investing and financing activities
Beneficial interests obtained in connection with loan sales	325,675	90,565	0
Securities retained under unconsolidated securitization transactions	95,880	13,001	13,172
Issuance of line of credit receivable	51,599	54,780	0
Capitalized stock-based compensation expense	9,382	4,320	6,666
Repayments of line of credit receivable	1,761	0	0
Settlement of borrowings in connection with loan sale	0	221,749	0
Securities retained under consolidated securitization transaction	0	0	44,763
Beneficial interest assets included in payable to investors	0	0	5,792
Cash and Restricted Cash
Cash and cash equivalents	652,388	788,422
Restricted cash	404,624	187,841
Total cash, cash equivalents and restricted cash	$ 1,057,012	$ 976,263	$ 467,787