Prosper Funding 10-Q 12 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Nov. 09, 2020
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2020
Entity File Number	333-225797-01
Entity Registrant Name	PROSPER MARKETPLACE, INC.
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001416265
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	73-1733867
Entity Address, Address Line One	221 Main Street
Entity Address, Address Line Two	3rd Floor
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94105
City Area Code	415
Local Phone Number	593-5400
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		68,858,586
Prosper Funding LLC
Entity Information [Line Items]
Entity File Number	333-225797
Entity Registrant Name	PROSPER FUNDING LLC
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001542574
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-4526070
Entity Address, Address Line One	221 Main Street
Entity Address, Address Line Two	3rd Floor
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94105
City Area Code	415
Local Phone Number	593-5400
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		0

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Assets
Cash and Cash Equivalents		$ 45,898	$ 64,635
Restricted Cash	[1]	135,826	155,773
Accounts Receivable	[1]	533	1,695
Loans Held for Sale, at Fair Value	[1]	252,443	142,026
Borrower Loans, at Fair Value	[1]	414,877	634,019
Property and Equipment, Net		29,583	31,296
Prepaid and Other Assets	[1]	6,131	5,694
Servicing Assets		9,306	12,602
Goodwill		36,368	36,368
Intangible Assets, Net		555	720
Total Assets		931,520	1,084,828
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Accounts Payable and Accrued Liabilities		14,600	19,937
Payable to Investors		95,887	101,092
Notes, at Fair Value		206,931	244,171
Notes Issued by Securitization Trust	[1]	192,829	347,662
Certificates Issued by Securitization Trust, at Fair Value	[1]	26,781	52,168
Warehouse Lines	[1]	226,784	131,583
Other Liabilities		26,218	21,726
Convertible Preferred Stock Warrant Liability		86,372	149,996
Total Liabilities		876,402	1,068,335
Commitments and Contingencies (Note 17)
Convertible Preferred Stock		322,748	322,748
Stockholders' Deficit
Common Stock – $0.01 par value; 625,000,000 shares authorized; 69,794,521 shares issued and 68,858,586 shares outstanding, as of September 30, 2020; 69,387,836 shares issued and 68,451,901 shares outstanding, as of December 31, 2019.		212	208
Additional Paid-In Capital		155,672	151,416
Less: Treasury Stock		(23,417)	(23,417)
Accumulated Deficit		(397,716)	(434,462)
Total Stockholders' Deficit		(265,249)	(306,255)
Total Liabilities, Convertible Preferred Stock and Stockholders' Deficit		931,520	1,084,828
Prosper Funding LLC
Assets
Cash and Cash Equivalents		7,950	7,462
Restricted Cash		111,020	110,399
Borrower Loans, at Fair Value		208,044	245,137
Property and Equipment, Net		7,351	7,549
Servicing Assets		11,265	14,888
Other Assets		245	749
Total Assets		345,875	386,184
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Accounts Payable and Accrued Liabilities		2,394	2,133
Payable to Related Party		10,581	2,679
Payable to Investors		98,021	105,287
Notes, at Fair Value		206,931	244,171
Other Liabilities		2,700	3,727
Total Liabilities		320,627	357,997
Stockholders' Deficit
Member's Equity		11,404	15,904
Accumulated Deficit		13,844	12,283
Total Stockholders' Deficit		25,248	28,187
Total Liabilities, Convertible Preferred Stock and Stockholders' Deficit		345,875	386,184
Primary Beneficiary
Assets
Restricted Cash	[2]	25,637	39,118
Accounts Receivable	[2]	0	73
Loans Held for Sale, at Fair Value	[2]	252,443	142,026
Borrower Loans, at Fair Value	[2]	206,833	388,882
Prepaid and Other Assets	[2]	2,265	2,928
Total Assets	[2]	487,178	573,027
Liabilities, Convertible Preferred Stock and Stockholders' Deficit
Notes Issued by Securitization Trust	[2]	192,829	347,662
Certificates Issued by Securitization Trust, at Fair Value	[2]	26,781	52,168
Warehouse Lines	[2]	226,784	131,583
Total Liabilities	[2]	446,394	531,413
Convertible Preferred Stock		$ 2,381	$ 0
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.
[2]	The following table presents the assets and liabilities of consolidated variable interest entities (VIEs), which are included in the condensed consolidated balance sheets above. The assets in the table below may only be used to settle obligations of consolidated VIEs and are in excess of those obligations. Additionally, the assets and liabilities in the table below include third-party assets and liabilities of consolidated VIEs only and exclude intercompany balances that eliminate in consolidation. See Note 6, Securitizations, and Note 10, Debt, to our Notes to Condensed Consolidated Financial Statements for add itional information.

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Sep. 20, 2017
Convertible preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Convertible preferred stock, authorized (in shares)	444,760,848	444,760,848	444,760,848
Convertible preferred stock, issued (in shares)	209,613,570	209,613,570
Convertible preferred stock, outstanding (in shares)	209,613,570	209,613,570
Convertible preferred stock, aggregate liquidation preference	$ 370,456	$ 370,456
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01	$ 0.01
Common stock, authorized (in shares)	625,000,000	625,000,000	625,000,000
Common stock, issued (in shares)	69,794,521	69,387,836
Common stock, outstanding (in shares)	68,858,586	68,451,901
Primary Beneficiary
Convertible preferred stock, issued (in shares)	51,247,915	0
Convertible preferred stock, outstanding (in shares)	51,247,915	0

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating Revenues
Revenues	$ 20,826,000	$ 42,816,000	$ 67,296,000	$ 106,289,000
Gain (Loss) on Sale of Borrower Loans	786,000	2,577,000	3,147,000	8,834,000
Fair Value of Warrants Vested on Sale of Borrower Loans	0	0	0	(17,553,000)
Interest Income
Interest Income on Borrower Loans and Loans Held for Sale	25,693,000	29,113,000	79,982,000	71,084,000
Interest Expense on Financial Instruments	(14,519,000)	(17,339,000)	(46,472,000)	(46,104,000)
Net Interest Income	11,174,000	11,774,000	33,510,000	24,980,000
Change in Fair Value of Financial Instruments, Net	4,703,000	(11,229,000)	(34,601,000)	(14,901,000)
Total Net Revenue	36,703,000	43,361,000	66,205,000	116,368,000
Expenses
Origination and Servicing	6,871,000	8,464,000	22,682,000	26,052,000
Sales and Marketing	5,362,000	20,484,000	21,626,000	58,275,000
General and Administrative	15,151,000	18,195,000	49,033,000	54,879,000
Impairment Expense	0	0	228,000	0
Restructuring Charges, Net	0	7,000	0	86,000
Change in Fair Value of Convertible Preferred Stock Warrants	11,374,000	(14,217,000)	(63,624,000)	(8,890,000)
Other Income, Net	(64,000)	(370,000)	(588,000)	(1,607,000)
Total Expenses	38,694,000	32,563,000	29,357,000	128,795,000
Net (Loss) Income Before Taxes	(1,991,000)	10,798,000	36,848,000	(12,427,000)
Income Tax Expense	34,000	29,000	102,000	87,000
Net (Loss) Income	(2,025,000)	10,769,000	36,746,000	(12,514,000)
Plus: Return on Share Purchase	(2,381,000)	0	(2,381,000)	0
Less: Net Income Allocated to Participating Securities	255,000	7,994,000	28,814,000	0
Net Income (Loss) Attributable to Common Stockholders	$ 101,000	$ 2,775,000	$ 10,313,000	$ (12,514,000)
Net Income (Loss) Per Share - Basic (in dollars per share)	$ 0	$ 0.04	$ 0.15	$ (0.18)
Net Income (Loss) Per Share - Diluted (in dollars per share)	$ 0	$ 0.01	$ 0.03	$ (0.18)
Weighted-Average Shares - Basic (in shares)	68,485,173	70,606,805	68,465,046	70,532,641
Weighted-Average Shares - Diluted (in shares)	296,652,189	285,810,755	332,508,175	70,532,641
Prosper Funding LLC
Operating Revenues
Revenues	$ 11,578,000	$ 18,538,000	$ 36,396,000	$ 54,193,000
Gain (Loss) on Sale of Borrower Loans	1,247,000	3,155,000	4,429,000	(7,725,000)
Interest Income
Interest Income on Borrower Loans and Loans Held for Sale	8,979,000	10,304,000	28,126,000	31,038,000
Interest Expense on Financial Instruments	(8,419,000)	(9,647,000)	(26,363,000)	(29,031,000)
Net Interest Income	560,000	657,000	1,763,000	2,007,000
Change in Fair Value on Borrower Loans, Loans Held for Sale and Notes, Net	(72,000)	(120,000)	185,000	(338,000)
Total Net Revenue	12,066,000	19,075,000	38,344,000	55,862,000
Expenses
Administration Fee - Related Party	10,997,000	16,079,000	32,855,000	47,845,000
Servicing	1,327,000	1,178,000	3,657,000	3,550,000
General and Administrative	104,000	38,000	271,000	166,000
Total Expenses	12,428,000	17,295,000	36,783,000	51,561,000
Income Tax Expense			0	0
Net (Loss) Income	(362,000)	1,780,000	1,561,000	4,301,000
Administration Fee Revenue - Related Party | Prosper Funding LLC
Operating Revenues
Revenues	5,158,000	8,854,000	14,733,000	42,469,000
Transaction Fees, Net
Operating Revenues
Revenues	15,075,000	32,466,000	46,889,000	92,637,000
Servicing Fees, Net
Operating Revenues
Revenues	4,396,000	6,165,000	15,113,000	17,540,000
Servicing Fees, Net | Prosper Funding LLC
Operating Revenues
Revenues	5,066,000	6,473,000	16,782,000	19,350,000
Other Revenue
Operating Revenues
Revenues	569,000	1,608,000	2,147,000	4,831,000
Other Revenue | Prosper Funding LLC
Operating Revenues
Revenues	$ 107,000	$ 56,000	$ 452,000	$ 99,000

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Other Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ (2,025)	$ 10,769	$ 36,746	$ (12,514)
Other Comprehensive (Loss) Income, Before Tax
Change in Net Unrealized (Loss) Gain on Available for Sale Investments, at Fair Value	0	(8)	0	13
Other Comprehensive (Loss) Income, Before Tax	0	(8)	0	13
Income Tax Effect	0	0	0	0
Other Comprehensive (Loss) Income, Net of Tax	0	(8)	0	13
Comprehensive (Loss) Income, Net of Tax	$ (2,025)	$ 10,761	$ 36,746	$ (12,501)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Convertible Preferred Stock, Stockholders’ Deficit and Members' Equity (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Convertible Preferred Stock Held by Consolidated VIE	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Retained Earnings (Accumulated Deficit)	Prosper Funding LLC	Prosper Funding LLCRetained Earnings (Accumulated Deficit)	Prosper Funding LLCMember’s Equity
Beginning balance (in shares) at Dec. 31, 2018		214,637,925	0
Beginning balance at Dec. 31, 2018		$ 323,793
Ending balance (in shares) at Mar. 31, 2019		214,637,925	0
Ending balance at Mar. 31, 2019		$ 323,793
Beginning balance (in shares) at Dec. 31, 2018				75,652,445	(5,177,235)
Beginning balance at Dec. 31, 2018	$ (298,466)			$ 229	$ (23,417)	$ 145,486	$ (13)	$ (420,751)	$ 31,245	$ 6,341	$ 24,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of vested stock options (in shares)				16,085
Exercise of vested stock options	4					4
Stock-based Compensation Expense	1,714					1,714
Change in net unrealized loss on available for sale investments, at fair value	10						10
Net Income (Loss)	(22,714)							(22,714)	1,291	1,291
Ending balance (in shares) at Mar. 31, 2019				75,668,530	(5,177,235)
Ending balance at Mar. 31, 2019	(319,452)			$ 229	$ (23,417)	147,204	(3)	(443,465)	32,536	7,632	24,904
Beginning balance (in shares) at Dec. 31, 2018		214,637,925	0
Beginning balance at Dec. 31, 2018		$ 323,793
Ending balance (in shares) at Sep. 30, 2019		214,637,925	0
Ending balance at Sep. 30, 2019		$ 323,793
Beginning balance (in shares) at Dec. 31, 2018				75,652,445	(5,177,235)
Beginning balance at Dec. 31, 2018	(298,466)			$ 229	$ (23,417)	145,486	(13)	(420,751)	31,245	6,341	24,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	(12,514)								4,301
Ending balance (in shares) at Sep. 30, 2019				75,814,801	(5,177,235)
Ending balance at Sep. 30, 2019	(306,854)			$ 230	$ (23,417)	149,598		(433,265)	35,546	10,642	24,904
Beginning balance (in shares) at Mar. 31, 2019		214,637,925	0
Beginning balance at Mar. 31, 2019		$ 323,793
Ending balance (in shares) at Jun. 30, 2019		214,637,925	0
Ending balance at Jun. 30, 2019		$ 323,793
Beginning balance (in shares) at Mar. 31, 2019				75,668,530	(5,177,235)
Beginning balance at Mar. 31, 2019	(319,452)			$ 229	$ (23,417)	147,204	(3)	(443,465)	32,536	7,632	24,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of vested stock options (in shares)				75,231
Exercise of vested stock options	9			$ 1		8
Stock-based Compensation Expense	1,316					1,316
Change in net unrealized loss on available for sale investments, at fair value	11						11
Net Income (Loss)	(569)							(569)	1,230	1,230
Ending balance (in shares) at Jun. 30, 2019				75,743,761	(5,177,235)
Ending balance at Jun. 30, 2019	(318,685)			$ 230	$ (23,417)	148,528	8	(444,034)	33,766	8,862	24,904
Ending balance (in shares) at Sep. 30, 2019		214,637,925	0
Ending balance at Sep. 30, 2019		$ 323,793
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of vested stock options (in shares)				71,040
Exercise of vested stock options	12					12
Restricted stock vested	0
Stock-based Compensation Expense	1,058					1,058
Change in net unrealized loss on available for sale investments, at fair value	(8)						(8)
Net Income (Loss)	10,769							10,769	1,780	1,780
Ending balance (in shares) at Sep. 30, 2019				75,814,801	(5,177,235)
Ending balance at Sep. 30, 2019	$ (306,854)			$ 230	$ (23,417)	149,598		(433,265)	35,546	10,642	24,904
Beginning balance (in shares) at Dec. 31, 2019	209,613,570	209,613,570	0
Beginning balance at Dec. 31, 2019	$ 322,748	$ 322,748	$ 0
Ending balance (in shares) at Mar. 31, 2020		209,613,570	0
Ending balance at Mar. 31, 2020		$ 322,748
Beginning balance (in shares) at Dec. 31, 2019				73,629,136	(5,177,235)
Beginning balance at Dec. 31, 2019	(306,255)			$ 208	$ (23,417)	151,416		(434,462)	28,187	12,283	15,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of vested stock options (in shares)				3,740
Exercise of vested stock options	1					1
Stock-based Compensation Expense	557					557
Net Income (Loss)	21,130							21,130	1,548	1,548
Ending balance (in shares) at Mar. 31, 2020				73,632,876	(5,177,235)
Ending balance at Mar. 31, 2020	$ (284,567)			$ 208	$ (23,417)	151,974		(413,332)	29,735	13,831	15,904
Beginning balance (in shares) at Dec. 31, 2019	209,613,570	209,613,570	0
Beginning balance at Dec. 31, 2019	$ 322,748	$ 322,748	$ 0
Ending balance (in shares) at Sep. 30, 2020	209,613,570	209,613,570	(51,247,915)
Ending balance at Sep. 30, 2020	$ 322,748	$ 322,748	$ (2,381)
Beginning balance (in shares) at Dec. 31, 2019				73,629,136	(5,177,235)
Beginning balance at Dec. 31, 2019	(306,255)			$ 208	$ (23,417)	151,416		(434,462)	28,187	12,283	15,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	36,746								1,561
Ending balance (in shares) at Sep. 30, 2020				74,035,821	(5,177,235)
Ending balance at Sep. 30, 2020	(265,249)			$ 212	$ (23,417)	155,672	0	(397,716)	25,248	13,844	11,404
Beginning balance (in shares) at Mar. 31, 2020		209,613,570	0
Beginning balance at Mar. 31, 2020		$ 322,748
Ending balance (in shares) at Jun. 30, 2020		209,613,570	0
Ending balance at Jun. 30, 2020		$ 322,748
Beginning balance (in shares) at Mar. 31, 2020				73,632,876	(5,177,235)
Beginning balance at Mar. 31, 2020	(284,567)			$ 208	$ (23,417)	151,974		(413,332)	29,735	13,831	15,904
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based Compensation Expense	454					454
Distribution to Parent									(4,500)		(4,500)
Net Income (Loss)	17,641							17,641	375	375
Ending balance (in shares) at Jun. 30, 2020				73,632,876	(5,177,235)
Ending balance at Jun. 30, 2020	$ (266,472)			$ 208	$ (23,417)	152,428		(395,691)	25,610	14,206	11,404
Increase (Decrease) in Temporary Equity [Roll Forward]
Purchase of Convertible Preferred Stock by consolidated VIE Prosper Grantor Trust (Note 12) (in shares)			(51,247,915)
Purchase of Convertible Preferred Stock by consolidated VIE Prosper Grantor Trust (Note 12)			$ (2,381)
Ending balance (in shares) at Sep. 30, 2020	209,613,570	209,613,570	(51,247,915)
Ending balance at Sep. 30, 2020	$ 322,748	$ 322,748	$ (2,381)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of Convertible Preferred Stock by consolidated VIE Prosper Grantor Trust (Note 12)	2,381					2,381
Exercise of vested stock options (in shares)				402,945
Exercise of vested stock options	8			$ 4		4
Stock-based Compensation Expense	859					859
Net Income (Loss)	(2,025)							(2,025)	(362)	(362)
Ending balance (in shares) at Sep. 30, 2020				74,035,821	(5,177,235)
Ending balance at Sep. 30, 2020	$ (265,249)			$ 212	$ (23,417)	$ 155,672	$ 0	$ (397,716)	$ 25,248	$ 13,844	$ 11,404

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from Operating Activities:
Net Income (Loss)	$ 36,746,000	$ (12,514,000)
Adjustments to Reconcile Net Income (Loss) to Net Cash Used in Operating Activities:
Change in Fair Value of Financial Instruments, Net	34,597,000	16,259,000
Depreciation and Amortization	6,196,000	5,649,000
Amortization of Operating Lease Right-of-Use Asset	2,599,000	2,469,000
Impairment of Operating Lease Right-of-Use Asset	228,000	0
Gain on Sales of Borrower Loans	(3,945,000)	(9,237,000)
Change in Fair Value of Servicing Rights	7,241,000	9,930,000
Stock-Based Compensation Expense	1,683,000	3,838,000
Fair Value of Warrants Vested on Sale of Borrower Loans	0	17,553,000
Change in Fair Value of Convertible Preferred Stock Warrants	(63,624,000)	(8,890,000)
Other, Net	1,177,000	369,000
Changes in Operating Assets and Liabilities:
Purchase of Loans Held for Sale at Fair Value	(949,529,000)	(1,809,133,000)
Proceeds from Sales and Principal Payments of Loans Held for Sale at Fair Value	874,489,000	1,656,506,000
Accounts Receivable	1,162,000	3,449,000
Prepaid and Other Assets	(437,000)	(4,000)
Accounts Payable and Accrued Liabilities	(5,204,000)	452,000
Payable to Investors	(5,205,000)	(14,031,000)
Other Liabilities	(4,101,000)	(3,245,000)
Net Cash Used in Operating Activities	(65,927,000)	(140,580,000)
Cash Flows from Investing Activities:
Purchase of Borrower Loans Held at Fair Value	(97,406,000)	(127,524,000)
Proceeds from Sales and Principal Payments of Borrower Loans Held at Fair Value	217,527,000	179,298,000
Purchases of Property and Equipment	(6,801,000)	(7,657,000)
Purchases of Available for Sale Investments, at Fair Value	0	(1,488,000)
Maturities of Available for Sale Investments	0	22,263,000
Net Cash Provided by Investing Activities	113,320,000	64,892,000
Cash Flows from Financing Activities:
Proceeds from Issuance of Notes Held at Fair Value	97,303,000	128,152,000
Payments of Notes Held at Fair Value	(114,050,000)	(126,721,000)
Principal Payments on Notes Issued by Securitization Trust	(156,377,000)	(83,419,000)
Principal Payments on Certificates Issued by Securitization Trust	(16,608,000)	(8,445,000)
Proceeds from Securitization Issuance	0	5,642,000
Proceeds from Warehouse Lines	110,499,000	173,611,000
Principal Payments on Warehouse Lines	(15,300,000)	0
Proceeds from Paycheck Protection Program Loan	8,447,000	0
Payment for Debt Issuance Costs	0	(6,614,000)
Proceeds from Exercise of Stock Options	9,000	25,000
Net Cash (Used in) Provided by Financing Activities	(86,077,000)	82,231,000
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	(38,684,000)	6,543,000
Cash, Cash Equivalents and Restricted Cash at Beginning of the Period	220,408,000	207,059,000
Cash, Cash Equivalents and Restricted Cash at End of the Period	181,724,000	213,602,000
Supplemental Disclosure of Cash Flow Information:
Cash Paid for Interest	44,647,000	44,253,000
Non-Cash Investing Activity - Accrual for Property and Equipment, Net	574,000	516,000
Non-Cash Investing Activity - Consolidation of Borrower Loans, at Fair Value	0	(262,565,000)
Non-Cash Financing Activity - Issuance of Securitization Notes and Certificates	0	395,544,000
Non-Cash Financing Activity - Derecognition of Warehouse Line Debt	0	(130,322,000)
Reconciliation to Amounts on Consolidated Balance Sheets
Total Cash, Cash Equivalents and Restricted Cash	181,724,000	213,602,000
Prosper Funding LLC
Cash flows from Operating Activities:
Net Income (Loss)	1,561,000	4,301,000
Adjustments to Reconcile Net Income (Loss) to Net Cash Used in Operating Activities:
Change in Fair Value of Financial Instruments, Net	(186,000)	337,000
Other Non-Cash Changes in Borrower Loans, Loans Held for Sale and Notes	48,000	(312,000)
Depreciation and Amortization	3,132,000	3,279,000
Gain on Sales of Borrower Loans	(5,034,000)	(10,232,000)
Change in Fair Value of Servicing Rights	8,657,000	10,552,000
Changes in Operating Assets and Liabilities:
Purchase of Loans Held for Sale at Fair Value	(949,529,000)	(1,809,133,000)
Proceeds from Sales and Principal Payments of Loans Held for Sale at Fair Value	949,529,000	1,809,133,000
Other Assets	504,000	(324,000)
Accounts Payable and Accrued Liabilities	261,000	(3,182,000)
Payable to Investors	(7,266,000)	(9,495,000)
Net Related Party Receivable/Payable	7,910,000	360,000
Other Liabilities	(1,027,000)	46,000
Net Cash Used in Operating Activities	8,560,000	(4,670,000)
Cash Flows from Investing Activities:
Purchase of Borrower Loans Held at Fair Value	(97,406,000)	(127,522,000)
Proceeds from Sales and Principal Payments of Borrower Loans Held at Fair Value	114,145,000	125,592,000
Purchases of Property and Equipment	(2,942,000)	(2,854,000)
Net Cash Provided by Investing Activities	13,797,000	(4,784,000)
Cash Flows from Financing Activities:
Proceeds from Issuance of Notes Held at Fair Value	97,303,000	128,152,000
Payments of Notes Held at Fair Value	(114,051,000)	(126,721,000)
Cash Distributions to Parent	(4,500,000)	0
Net Cash (Used in) Provided by Financing Activities	(21,248,000)	1,431,000
Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash	1,109,000	(8,023,000)
Cash, Cash Equivalents and Restricted Cash at Beginning of the Period	117,861,000	147,181,000
Cash, Cash Equivalents and Restricted Cash at End of the Period	118,970,000	139,158,000
Supplemental Disclosure of Cash Flow Information:
Cash Paid for Interest	26,353,000	29,568,000
Non-Cash Investing Activity - Accrual for Property and Equipment, Net	238,000	32,000
Reconciliation to Amounts on Consolidated Balance Sheets
Total Cash, Cash Equivalents and Restricted Cash	$ 118,970,000	$ 139,158,000

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Marketplace, Inc. (“PMI”) was incorporated in the state of Delaware on March 22, 2005. Except as the context requires otherwise, as used in these notes to the condensed consolidated financial statements of PMI, “Prosper,” “we,” “us,” and “our” refer to PMI and its wholly-owned subsidiaries, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2019. The balance sheet at December 31, 2019 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. The preparation of Prosper’s condensed consolidated financial statements and related disclosures in conformity with US GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in Prosper’s financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions. The accompanying interim condensed consolidated financial statements include the accounts of PMI, its wholly-owned subsidiaries and consolidated variable interest entities (“VIEs”). All intercompany balances have been eliminated in consolidation. Securitization Notes are notes held by certain third party investors pursuant to Prosper’s securitization transactions, and are distinguishable from the borrower payment dependent Notes available to investors through our Note Channel.
Prosper Funding LLC
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Funding LLC (“PFL”) was formed in the state of Delaware in February 2012 as a limited liability company with the Prosper Marketplace, Inc. (“PMI”) as its sole equity member. Except as the context otherwise requires, as used in these Notes to the condensed consolidated financial statements of PFL, “Prosper Funding,” “we,” “us,” and “our” refers to PFL and its wholly owned subsidiary, Prosper Depositor LLC, a Delaware limited liability company, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2019. The balance sheet at December 31, 2019 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. Prosper Funding did not have any items of other comprehensive income or loss for any of the periods presented in the condensed consolidated financial statements as of and for the nine months ended September 30, 2020 and September 30, 2019. The preparation of Prosper Funding's condensed consolidated financial statements and related disclosures in conformity with US GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in its condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions, and the differences could be material.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Prosper’s significant accounting policies are included in Note 2, Summary of Significant Accounting Policies, in Prosper’s Annual Report on Form 10-K for the year ended December 31, 2019. There have been no changes to these accounting policies during the first nine months of 2020 unless noted below. Fair Value Measurements Financial instruments measured at fair value consist principally of Borrower Loans, Loans Held for Sale, Servicing Assets, Notes, Certificates Issued by Securitization Trust and Convertible Preferred Stock Warrant Liability. The estimated fair values of other financial instruments, including Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short-term nature. The estimated fair values of Notes Issued by Securitization Trust and Warehouse Lines do not approximate their carrying values due primarily to differences in the stated and market rates associated with these instruments. Refer to Note 7, Fair Value of Assets and Liabilities, for additional fair value disclosures. Restricted Cash Restricted Cash consists primarily of cash deposits, money market funds and short term certificate of deposit accounts held as collateral as required for long term leases, loan funding and servicing activities, and cash that investors have on our marketplace that has not yet been invested in Borrower Loans or disbursed to the investor. Borrower Loans, Loans Held for Sale, Notes and Certificates Issued by Securitization Trust Borrower Loans are funded either through the Note Channel or through the Whole Loan Channel. Through the Note Channel, Prosper purchases Borrower Loans from WebBank, then issues Notes and holds the Borrower Loans until maturity. The obligation to repay a series of Notes issued through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans funded and Notes issued through the Note Channel are carried on Prosper’s condensed consolidated balance sheets as assets and liabilities, respectively. In 2019, Prosper began refinancing the purchase of Borrower Loans through the Whole Loan Channel through securitization transactions, which issue senior notes, risk retention interests and residual certificates. Associated securitization trusts are deemed consolidated VIEs, and as a result the Borrower Loans held in the securitization trusts are included in “Borrower Loans, at Fair Value”. Senior notes sold to third party investors are included in “Notes Issued by Securitization Trust,” and the risk retention interest and residual certificates held by third party investors are included in “Certificates Issued by Securitization Trust, at Fair Value” on the accompanying condensed consolidated balance sheets. Refer to Note 6 , Securitization for additional disclosures. Prosper uses Warehouse Lines to purchase Loans Held for Sale that may be subsequently contributed to securitization transactions or sold to investors. Loans Held for Sale are included in “Loans Held for Sale, at Fair Value” on the Consolidated Balance Sheets. See Note 10, Debt for more details on Warehouse Lines. Borrower Loans and Loans Held for Sale are purchased from WebBank. Prosper places Borrower Loans and Loans Held for Sale on non-accrual status when they are 120 days past due. When a loan is placed on non-accrual status, Prosper stops accruing interest and reverses all accrued but unpaid interest as of such date. Additionally, Prosper charges-off Borrower Loans and Loans Held for Sale when they are 120 days past due. The fair value of loans 120 or more days past due generally consists of the expected recovery from debt sales in subsequent periods. Prosper has elected the fair value option for Borrower Loans, Loans Held for Sale, Notes, and Certificates Issued by Securitization Trust. Changes in fair value of Borrower Loans funded through the Note Channel are largely offset by the changes in fair value of Notes due to the borrower payment-dependent design of the Notes. Changes in fair value of Borrower Loans held in consolidated securitization trusts are partially offset by changes in fair value of the Certificates Issued by Securitization Trust. Changes in fair value of Loans Held for Sale are recorded through Proper's earnings and Prosper collects interest on Loans Held for Sale. Changes in the fair values of Borrower Loans, Loans Held for Sale, Notes, and Certificates Issued by Securitization Trust are included in “Change in Fair Value of Financial Instruments, Net” on the Consolidated Statements of Operations. Prosper primarily uses a discounted cash flow model to estimate the fair value of Borrower Loans, Loans Held for Sale, Notes, and Certificates Issued by Securitization Trust. The key assumptions used in the valuation include default rates and prepayment rates derived primarily from historical performance, and discount rates based on estimates of the rates of return that investors would require when investing in financial instruments with similar characteristics. Leases Management determines if an arrangement is a lease at inception. Operating lease right-of-use (“ROU”) assets and operating lease liabilities are included on the Consolidated Balance Sheets in Property and Equipment, Net and in Other Liabilities, respectively. For certain leases with original terms of twelve months or less, PMI recognizes the lease expense as incurred and does not record ROU assets and lease liabilities. If a contract contains a lease, management evaluates whether it should be classified as an operating or finance lease. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. As most of PMI's leases do not provide an implicit rate, management uses an incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The operating lease ROU assets are evaluated for impairment utilizing the same impairment model used for Property and Equipment. Consolidation of Variable Interest Entities The determination of whether to consolidate a VIE in which we have a variable interest requires a significant amount of analysis and judgment regarding whether we are the primary beneficiary of a VIE due to our holding a controlling financial interest in the VIE. A controlling financial interest in a VIE exists if we have both the power to direct the VIE’s activities that most significantly affect the VIE’s economic performance and a potentially significant economic interest in the VIE. The determination of whether an entity is a VIE considers factors, such as (i) whether the entity’s equity investment at risk is insufficient to allow the entity to finance its activities without additional subordinated financial support and (ii) whether a holder’s equity investment at risk lacks any of the following characteristics of a controlling financial interest: the direct or indirect ability through voting rights or similar rights to make decisions about a legal entity’s activities that have a significant effect on the entity’s success, the obligation to absorb the expected losses of the entity or the right to receive the expected residual returns of the legal entity. Management regularly reviews and reconsiders its previous conclusions regarding the status of an entity as a VIE and whether we are required to consolidate such VIE in the consolidated financial statements. Recent Accounting Pronouncements Accounting Standards Adopted by the Company in the Current Year In June 2016, the Financial Accounting Standards Board (“FASB”) amended guidance related to impairment of financial instruments as part of Accounting Standards Update (“ASU”) No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which is effective for interim and annual periods beginning after December 15, 2019. Prosper adopted the standard in the first quarter of 2020. For loans accounted for at amortized cost, the guidance replaces the incurred loss impairment methodology with an expected credit loss model for which a company recognizes an allowance based on the estimate of expected credit loss. Because Prosper accounts for Borrower Loans at fair value through net income there was no impact on Prosper loan portfolios upon adoption. For certain available for sale investments, the guidance requires recognition of expected credit losses through recording an allowance for credit losses. The recognition of this allowance is limited to the difference between the security’s amortized cost basis and fair value. The amendments to the available for sale debt securities impairment model did not have a material impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” Prior to ASU No. 2017-04, the goodwill impairment test was a two-step assessment, if indicators of impairment existed. The standard eliminates Step 2 from the goodwill impairment test, which requires a hypothetical purchase price allocation. Instead, entities will record a goodwill impairment charge based on the excess of a reporting unit's carrying amount over its fair value. The standard is effective for interim and annual periods beginning after December 15, 2019 and early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. Prosper adopted the guidance on a prospective basis in the first quarter of 2020, and there was no impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” Entities are no longer required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. ASU No. 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years, but entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. Prosper adopted the guidance in the first quarter of 2020. The guidance only affects disclosures in the notes to the consolidated financial statements and it had no effect on Prosper’s balance sheet or statement of operations. In August 2018, the FASB issued ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within that fiscal year and early adoption is permitted. The Company adopted the new guidance in the first quarter of 2020, and will prospectively capitalize all eligible costs related to cloud computing arrangements starting January 1, 2020. There was, however, no impact on the Company’s consolidated financial statements for the first nine months of 2020. Accounting Standards Issued, to be Adopted by the Company in Future Periods In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” This ASU simplifies the accounting for income taxes by removing certain exceptions related to the incremental approach for intraperiod tax allocation, the requirement to recognize or derecognize deferred tax liabilities related to equity method investments that are also foreign subsidiaries and the methodology for calculating income taxes in an interim period. The guidance also clarifies and simplifies other aspects of the accounting for income taxes, including a modification in the guidance for franchise taxes that are partially based on income and recognizing deferred taxes for a subsequent step-up in the tax basis of goodwill. This ASU is effective for annual periods beginning after December 15, 2020, including interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact this new standard will have on the Company’s consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848),” which provides optional expedients and exceptions for applying GAAP on contract modifications and hedge accounting, in order to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative referenced rates, such as the Secured Overnight Financing Rate. This ASU can be adopted after its issuance date through December 31, 2022. The Company is currently evaluating the impact reference rate reform will have on its contracts that reference LIBOR in order to determine whether to adopt this guidance.
Prosper Funding LLC
Entity Information [Line Items]
Summary of Significant Accounting Policies	Significant Accounting Policies Prosper Funding's significant accounting policies are included in Note 2, Summary of Significant Accounting Policies, in Prosper Funding’s Annual Report on Form 10-K for the year ended December 31, 2019. There have been no changes to these accounting policies during the first nine months of 2020. Fair Value Measurements Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors and Notes. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature. Refer to Note 7 for additional fair value disclosures. Restricted Cash Restricted Cash consists primarily of cash deposits, money market funds and short term certificate of deposit accounts held as collateral as required for long term leases, loan funding and servicing activities, and cash that investors have on our marketplace that has not yet been invested in Borrower Loans or disbursed to the investor. Borrower Loans, Loans Held for Sale and Notes With respect to the Note Channel, Prosper Funding purchases Borrower Loans from WebBank, then issues Notes and holds the Borrower Loans until maturity. The obligation to repay a series of Notes funded through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans and Notes funded through the Note Channel are carried on Prosper Funding’s condensed consolidated balance sheets as assets and liabilities, respectively. Prosper Funding places Borrower Loans and Loans Held for Sale on non-accrual status when they are 120 days past due. When a loan is placed on non-accrual status, Prosper stops accruing interest and reverses all accrued but unpaid interest as of such date. Additionally, Prosper charges-off Borrower Loans and Loans Held for Sale when they are 120 days past due. The fair value of loans 120 days past due generally consists of the expected recovery from debt sales in subsequent periods. Management has elected the fair value option for Borrower Loans, Loans Held for Sale, and Notes. Changes in fair value of Borrower Loans are largely offset by the changes in fair value of Notes due to the borrower payment-dependent design of the Notes. Changes in fair value of Borrower Loans, Loans Held for Sale and Notes are included in “Change in Fair Value of Borrower Loans, Loans Held for Sale and Notes, Net” on the Consolidated Statements of Operations. Prosper Funding primarily uses a discounted cash flow model to estimate the fair value of Borrower Loans, Loans Held for Sale and Notes. The key assumptions used in the valuation include default rates and prepayment rates derived primarily from historical performance and discount rates based on estimates of the rates of return that investors would require when investing in financial instruments with similar characteristics. Recent Accounting Pronouncements Accounting Standards Adopted In The Current Period In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurement (Topic 820); Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” Entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. ASU No. 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years, but entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. The guidance only affects disclosures in the notes to the consolidated financial statements and has no effect on Prosper Funding’s balance sheet or statements of operations. Accounting Standards Issued, To Be Adopted By Prosper Funding In Future Periods No issued and pending accounting standards were identified that are expected to have an impact on Prosper Funding.

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Property and Equipment, Net	Property and Equipment, Net Property and Equipment consists of the following at the dates presented (in thousands): September 30, 2020 December 31, 2019 Operating lease right-of-use assets $ 15,984 $ 16,213 Computer equipment 13,558 13,420 Internal-use software and website development costs 32,446 28,904 Office equipment and furniture 2,999 2,999 Leasehold improvements 7,167 7,158 Assets not yet placed in service 4,020 2,445 Property and equipment 76,174 71,139 Less: Accumulated depreciation and amortization (46,591) (39,843) Total Property and Equipment, Net $ 29,583 $ 31,296 Depreciation and amortization expense for Property and Equipment for the three months ended September 30, 2020 and September 30, 2019 was $2.1 million and $1.8 million, respectively. Depreciation and amortization expense for Property and Equipment for the nine months ended September 30, 2020 and September 30, 2019 was $6.0 million and $5.4 million, respectively. These charges are included in General and Administrative expenses on the condensed consolidated statements of operations. Prosper capitalized internal-use software and website development costs in the amount of $1.8 million and $2.6 million for the three months ended September 30, 2020 and September 30, 2019, respectively, and $6.5 million and $6.9 million for the nine months ended September 30, 2020 and September 30, 2019, respectively. Additionally, disclosures ar ound the operating lease right-of-use ass ets are included in Note 16.
Prosper Funding LLC
Entity Information [Line Items]
Property and Equipment, Net	Property and Equipment Property and equipment consist of the following (in thousands): September 30, 2020 December 31, 2019 Internal-use software and web site development costs $ 26,437 $ 24,930 Less accumulated depreciation and amortization (19,086) (17,381) Total property and equipment, net $ 7,351 $ 7,549 Depreciation expense for the three months ended September 30, 2020 and 2019 wa s $1.1 million and $1.1 million, respectively. Depreciation expense for the nine months ended September 30, 2020 and 2019 wa

Borrower Loans, Loans Held for

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value	Borrower Loans, Loans Held for Sale, and Notes, Held at Fair Value The aggregate principal balances outstanding and fair values of Borrower Loans, Loans Held for Sale, and Notes as of September 30, 2020 and December 31, 2019, are presented in the following table (in thousands): Borrower Loans Loans Held for Sale Notes September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 Aggregate principal balance outstanding $ 440,460 $ 647,209 $ 260,405 $ 143,261 $ (219,730) $ (250,281) Fair value adjustments (25,583) (13,190) (7,962) (1,235) 12,799 6,110 Fair value $ 414,877 $ 634,019 $ 252,443 $ 142,026 $ (206,931) $ (244,171) Borrower Loans At September 30, 2020, outstanding Borrower Loans had original terms to maturity of either 36 or 60 months, had monthly payments with fixed interest rates ranging from 5.31% to 31.82%, and ha d various maturity dates through September 2025. At December 31, 2019, outstanding Borrower Loans had original maturities of either 36 or 60 months, had mont hly payments with fixed interest rates ranging from 5.31% to 31.92%, and had various maturity dates through December 2024. As of September 30, 2020, Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $3.5 million and a fair value of $0.3 million. As of December 31, 2019, Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $6.5 million and a fair value of $1.9 million . Prosper places loans on non-accrual status when they are over 120 days past due. As of September 30, 2020 and December 31, 2019, Borrower Loans in non-accrual status had a fair value of $0.3 million a nd $0.7 million, respectively. Loans Held for Sale At September 30, 2020, outstanding Loans Held for Sale had original terms to maturity between 36 months and 60 months, had monthly payments with fixed interest rates ranging from 5.31% to 31.82% and had various maturity dates through September 2025. At December 31, 2019, outstanding Loans Held for Sale had original terms to maturity between 36 months and 60 months , had monthly payments with fixed interest rates ranging from 5.31% to 31.82% and had various maturity dates through December 2024. Fair value adjustments recorded in earnings on loans invested in by the Company resulted in net losses of $12.9 million and $3.4 million for the nine months ended September 30, 2020 and 2019, respectively. Interest income earned on Loans Held for Sale by the Company was $19.2 million and $13.1 million for the nine months e nded September 30, 2020 and September 30, 2019, respectively. As of September 30, 2020, Loans Held for Sale that were 90 days or more delinquent had an aggregate principal amount of $0.8 million and a fair value of $0.1 million . As of December 31, 2019, Loans Held for S ale that were 90 days or more delinquent had an aggregate principal amount of $0.7 million and a fair value of $0.2 million . Prosper places loans on non-accrual status when they are over 120 days past due. As of September 30, 2020 and December 31, 2019, Loans Held for Sale in non-accrual status had a fair value of $0.1 million (for both periods).
Prosper Funding LLC
Entity Information [Line Items]
Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value	Borrower Loans and Notes Held at Fair Value The aggregate principal balances outstanding and fair values of Borrower Loans and Notes as of September 30, 2020 and December 31, 2019, are presented in the following table (in thousands): Borrower Loans Notes September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 Aggregate principal balance outstanding $ 218,064 $ 248,702 $ (219,730) $ (250,281) Fair value adjustments (10,020) (3,565) 12,799 6,110 Fair value $ 208,044 $ 245,137 $ (206,931) $ (244,171) At September 30, 2020, outstanding Borrower Loans had original terms to maturity of either 36 or 60 months, had monthly payments with fixed interest rates ranging fro m 5.31% to 31.82% and had various maturity dates through September 2025. At December 31, 2019, outstanding Borrower Loans had original maturities of either 36 or 60 months, monthly payments with fixed interest rates ranging from 5.31% to 31.92%, and had various maturity da tes through December 2024. As of September 30, 2020, Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $1.3 million and a fair value of $0.1 million . As of December 31, 2019, Borrower Loans that were 90 days or more delinquent had an aggregate principal amount of $2.6 million and a fair value of $0.8 million. Prosper Funding places loans on non-accrual status when they are over 120 days past due. As of September 30, 2020 and December 31, 2019, Borrower Loans in non-accrual status had a fair value of $0.1 million a nd $0.3 million, respectively.

Loan Servicing Assets

Loan Servicing Assets	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Loan Servicing Assets	Loan Servicing Assets Prosper accounts for Servicing Assets at their estimated fair values with changes in fair values recorded in Servicing Fees. The initial asset or liability is recognized when Prosper sells Borrower Loans to unrelated third-party buyers through the Whole Loan Channel and the servicing rights are retained. The Servicing Assets are measured at fair value throughout the servicing period. The total gains recognized on the sale of such Borrower Loans for the three months ended September 30, 2020 and 2019 were $0.8 million and $2.6 million , respectively, recognized in Gain on Sale of Borrower Loans on the condensed consolidated statements of operations . The total gain recognized on the sale of such Borrower Loans for the nine months ended September 30, 2020 was $3.1 million, recognized in Gain on Sale of Borrower Loans on the condensed consolidated statement of operations . The total gains and losses recognized on the sale of such Borrower Loans for the nine months ended September 30, 2019 was a gain of $8.8 million, and a loss of $17.6 million from the Fair Value of Warrants Vested on the Sale of Borrower Loans to the Consortium. As of September 30, 2020, Borrower Loans that were sold but for which Prosper retained servicing rights had a total outstanding principal balance of $2.4 billion, original terms of either 36 or 60 months, monthly payments with fixed interest rates ranging from 5.31% to 31.92%, and various maturity dates through September 2025. A t December 31, 2019, Borrower Loans that were sold but for which Prosper retained servicing rights had a total outstanding principal balance of $3.1 billion, original terms of either 36 or 60 months, monthly payments with fixed interest rates ranging from 5.31% to 31.92%, and various maturity dates through December 2024. Contractually-specified servicing fees and ancillary fees totaling $6.7 million and $9.3 million for the three months ended September 30, 2020 and 2019 , respectively, and $23.2 million and $27.8 million for the nine months ended September 30, 2020 and 2019, respectively, are included on the condensed consolidated statements of operations in Servicing Fees, Net. Fair Value Valuation Method Prosper uses a discounted cash flow valuation methodology generally consisting of developing an estimate of future cash flows that are expected to occur over the life of a financial instrument and then discounting those cash flows at a rate of return that results in the fair value amount. Significant unobservable inputs presented in the table within Note 7 below are those that Prosper considers significant to the estimated fair values of the Level 3 Servicing Assets. The following is a description of the significant unobservable inputs provided in the table. Market Servicing Rate Prosper estimates adequate market servicing rates that would fairly compensate a substitute servicer should one be required, which includes the profit that would be demanded in the marketplace. This rate is stated as a fixed percentage of outstanding principal balance on a per annum basis. Prosper estimated these market servicing rates based on observable market rates for other loan types in the industry and bids from subservicing providers, adjusted for the unique loan attributes that are present in the specific loans that Prosper sells and services and information from backup service providers. Discount Rate The discount rate is a rate of return used to discount future expected cash flows to arrive at a present value, which represents the fair value of the loan servicing rights. We used a range of discount rates for the Servicing Assets based on comparable observed valuations of similar assets and publicly available disclosures related to servicing valuations, with comparability adjustments made to account for differences with Prosper’s servicing assets. Default Rate The default rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e., risk ratings and duration), and represents an aggregate of conditional default rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to default per period based on the term and age of the underlying Borrower Loans. The assumption regarding defaults directly reduces servicing revenues because the amount of servicing revenues received is based on the amount collected each period. Prepayment Rate The prepayment rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e., risk ratings and duration), and represents an aggregate of conditional prepayment rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to prepay per period based on the term and age of the underlying Borrower Loans. Prepayments reduce servicing revenues as they shorten the period over which we expect to collect fees on the Borrower Loans, which is used to project future servicing revenues.
Prosper Funding LLC
Entity Information [Line Items]
Loan Servicing Assets	Loan Servicing Assets Prosper Funding accounts for Servicing Assets at their estimated fair values with changes in fair values recorded in Servicing Fees, Net on the condensed consolidated statements of operations. The initial asset or liability is recognized when Prosper Funding sells Borrower Loans to unrelated third-party buyers through the Whole Loa n Channel and the servicing rights are retained. The total recognized gains on the sale of such Borrower Loans was $1.2 million and $3.2 million for the three months ended September 30, 2020 and 2019 , respectively. The total recognized gains and losses on the sale of such Borrower Loans was a $4.4 million gain and a $7.7 million loss for the nine months ended September 30, 2020 and 2019 , respectively. As of September 30, 2020, Borrower Loans that were sold, but for which Prosper Funding retained servicing rights, had a total outstanding principal balance of $2.9 billion, original terms of either 36 or 60 months , monthly payments with fixed interest rates ranging fr om 5.31% to 31.92%, and various maturity dates th rough September 2025. At December 31, 2019, Borrower Loans that were sold, but for which Prosper Funding retained servicing rights, had a total outstanding principal balance of $3.7 billion, original terms of either 36 or 60 months, monthly payments with fixed interest rates ranging from 5.31% to 31.92%, and various maturity dates through December 2024. Contractually-specified servicing fees and ancillary fees totaled $10.3 million and $10.7 million for the three months ended September 30, 2020 and 2019, respectively, and $33.3 million and $31.0 million for the nine months ended September 30, 2020 and 2019, respectively, and are included on the condensed consolidated statements of operations in Servicing Fees, Net. Fair Value Valuation Method Prosper Funding uses a discounted cash flow valuation methodology generally consisting of developing an estimate of future cash flows that are expected to occur over the life of a financial instrument and then discounting those cash flows at a rate of return that results in the fair value amount. Significant unobservable inputs presented in the table within Note 7 are those that Prosper Funding considers significant to the estimated fair values of the Level 3 Servicing Assets. The following is a description of the significant unobservable inputs provided in the table. Market Servicing Rate Prosper Funding estimates adequate market servicing rates that would fairly compensate a substitute servicer should one be required, which includes the profit that would be demanded in the marketplace. This rate is stated as a fixed percentage of outstanding principal balance on a per annum basis. Prosper Funding estimates these market servicing rates based on observable market rates for other loan types in the industry and bids from sub-servicing providers, adjusted for the unique loan attributes that are present in the specific loans that Prosper Funding sells and services and information from backup service providers. Discount Rate The discount rate is a rate of return used to discount future expected cash flows to arrive at a present value, which represents the fair value of the loan servicing rights. Management used a range of discount rates for the Servicing Assets based on comparable observed valuations of similar assets and publicly available disclosures related to servicing valuations, with comparability adjustments made to account for differences with Prosper Funding’s Servicing Assets. Default Rate The default rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e., risk ratings and duration), and represents an aggregate of conditional default rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to default per period based on the term and age of the underlying Borrower Loans. The assumption regarding defaults directly reduces servicing revenues because the amount of servicing revenues received is based on the amount collected each period. Prepayment Rate The prepayment rate presented in Note 7 is an annualized, average estimate considering all Borrower Loan categories (i.e., risk ratings and duration), and represents an aggregate of conditional prepayment rate curves for each credit grade or Borrower Loan category. Each point on a particular Borrower Loan category’s curve represents the percentage of principal expected to prepay per period based on the term and age of the underlying Borrower Loans. Prepayments reduce servicing revenues as they shorten the period over which Prosper Funding expects to collect fees on the Borrower Loans, which is used to project future servicing revenues.

Securitizations

Securitizations	9 Months Ended
	Sep. 30, 2020
Transfers and Servicing [Abstract]
Securitizations	Securitizations In 2019, Prosper co-sponsored and retained residual certificates in securitizations of unsecured personal whole loans facilitated through our marketplace with an aggregate outstanding principal balance of $573.0 million through three securitization trusts (PMIT 2019-1, PMIT 2019-2, and PMIT 2019-4). Each securitization trust issued senior notes, a risk retention interest and residual certificates to finance the purchase of Borrower Loans. The risk retention interest represents the right to receive 5.0% of all amounts collected on the Borrower Loans held by the securitization trusts. The resulting senior notes were sold to third party investors. Prosper retained 65.5%, 16.4%, and 19.6% of the residual certificates issued by PMIT 2019-1, PMIT 2019-2, and PMIT 2019-4, respectively. The remaining residual certificates and all the risk retention interests are held by third-party investors. In addition to the retained residual certificates, Prosper's continued involvement includes loan servicing responsibilities over the life of the underlying loans. PMIT 2019-1, 2019-2 and 2019-4 are deemed VIEs. Prosper consolidated the VIEs as the primary beneficiary because Prosper, through its role as the servicer, has both the power to direct the activities that most significantly affect the VIEs' economic performance and a variable interest that could potentially be significant to the VIEs through holding the retained residual certificates. In evaluating whether Prosper is the primary beneficiary, management considers both qualitative and quantitative factors regarding the nature, size and form of our involvement with the VIEs. Management assesses whether Prosper is the primary beneficiary of the VIEs on an on-going basis. For these VIEs, the creditors have no recourse to the general credit of Prosper and the liabilities of the VIEs can only be settled by the respective VIEs' assets. Additionally, the assets of the VIEs can be used only to settle obligations of the VIEs. Because Prosper consolidates the securitization trusts, the loans held in the securitization trusts are included in “Borrower Loans, at Fair Value”, the notes sold to third party investors recorded in “Notes Issued by Securitization Trust”, and the risk retention interests and residual certificates held by third party investors in “Certificates Issued by Securitization Trust, at Fair Value” in the condensed consolidated balance sheets. PMIT 2019-1 The notes under the PMIT 2019-1 securitization were issued in three classes: Class A in the amount of $127.3 million, Class B in the amount of $25.0 million and Class C in the amount of $19.3 million (collectively, the “2019-1 Notes”). The Class A, Class B and Class C notes bear interest at a fixed rate of 3.54%, 4.03% and 5.27%, respectively. Principal and interest payments began in March 2019 and are payable monthly. These notes are recorded at amortized cost on the balance sheet. The associated debt issuance costs of $2.3 million are deferred and amortized into interest expense over the contractual life of the notes. The notes held by third-party investors and the unamortized debt issuance costs are included in “Notes Issued by Securitization Trust” with a balance of $45.5 million on the condensed consolidated balance sheets as of September 30, 2020 and are secured by Borrower Loans at fair value of $47.6 million included in “Borrower Loans, at Fair Value” on the condensed consolidated balance sheets as of September 30, 2020. The risk retention and residual certificates held by third party investors at fair value of $4.5 million are included in “Certificates Issued by Securitization Trust, at Fair Value” on the condensed consolidated balance sheets as of September 30, 2020. PMIT 2019-2 The notes under the PMIT 2019-2 securitization were issued in three classes: Class A in the amount of $110.1 million, Class B in the amount of $31.4 million and Class C in the amount of $32.7 million (collectively, the “2019-2 Notes”). The Class A, Class B and Class C notes bear interest at a fixed rate of 3.20%, 3.69% and 5.05%, respectively. Principal and interest payments began in July 2019 and are payable monthly. These notes are recorded at amortized cost on the balance sheet. The associated debt issuance costs of $1.9 million are deferred and amortized into interest expense over the contractual life of the notes. The notes held by third-party investors and the unamortized debt issuance costs are included in “Notes Issued by Securitization Trust” with a balance of $69.6 million on the condensed consolidated balance sheets as of September 30, 2020 and are secured by Borrower Loans at fair value of $75.1 million of included in “Borrower Loans, at Fair Value” on the condensed consolidated balance sheets as of September 30, 2020. The risk retention and residual certificates held by third party investors at fair value of $10.9 million are included in “Certificates Issued by Securitization Trust, at Fair Value” on the condensed consolidated balance sheets as of September 30, 2020. PMIT 2019-4 The notes under the PMIT 2019-4 securitization were issued in three classes: Class A in the amount of $102.6 million, Class B in the amount of $19.5 million and Class C in the amount of $16.8 million (collectively, the “2019-4 Notes”). The Class A, Class B and Class C notes bear interest at a fixed rate of 2.48%, 3.20% and 4.95% respectively. Principal and interest payments began in December 2019 and are payable monthly. These notes are recorded at amortized cost on the balance sheet. The associated debt issuance costs of $1.2 million are deferred and amortized into interest expense over the contractual life of the notes. The notes held by third-party investors and the unamortized debt issuance costs are included in “Notes Issued by Securitization Trust” with a balance of $77.7 million and are secured by Borrower Loans at fair value of $84.1 million as of September 30, 2020. The risk retention interest and residual certificates held by third party investors at fair value of $11.4 million are included in “Certificates Issued by Securitization Trust, at Fair Value” in the condensed consolidated balance sheets as of September 30, 2020.

Fair Value of Assets and Liabil

Fair Value of Assets and Liabilities	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities Prosper measures the fair value of assets and liabilities in accordance with its fair value hierarchy which prioritizes information used to measure fair value and the effect of fair value measurements on earnings and provides for enhanced disclosures determined by the level within the hierarchy of information used in the valuation. The Company applies this framework whenever other standards require (or permit) assets or liabilities to be measured at fair value. Assets and liabilities carried at fair value on the balance sheets are classified among three levels based on the observability of the inputs used to determine fair value: Level 1 — The valuation is based on quoted prices in active markets for identical instruments. Level 2 — The valuation is based on observable inputs such as quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation methodologies for which all significant assumptions are observable in the market. Level 3 — The valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the instrument. Level 3 valuations are typically performed using pricing models, discounted cash flow methodologies, or similar methodologies, which incorporate management’s own estimates of assumptions that market participants would use in pricing the instrument or valuations that require significant management judgment or estimation. Fair values of assets or liabilities are determined based on the fair value hierarchy, which requires an entity to maximize the use of quoted prices and observable inputs and to minimize the use of unobservable inputs when measuring fair value. Various valuation methodologies are utilized, depending on the nature of the financial instrument, including the use of market prices for identical or similar instruments, or discounted cash flow models. When possible, active and observable market data for identical or similar financial instruments are utilized. Alternatively, fair value is determined using assumptions that management believes a market participant would use in pricing the asset or liability. Prosper did not transfer any assets or liabilities in or out of Level 3 for the three and nine months ended September 30, 2020 or 2019. Financial Instruments Recorded at Fair Value The fair value of the Borrower Loans, Loans Held for Sale, Notes, Certificates Issued by Securitization Trust, Servicing Rights and loan trailing fee liability are estimated using discounted cash flow methodologies based upon a set of valuation assumptions. The primary assumptions used in the discounted cash flow model include default and prepayment rates primarily derived from historical performance and discount rates applied to each credit grade based on the perceived credit risk of each credit grade. The Convertible Preferred Stock Warrant Liability is valued using a Black-Scholes option pricing model. Refer to Note 12 for further details. The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): September 30, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 414,877 $ 414,877 Loans Held for Sale — — 252,443 252,443 Servicing Assets — — 9,306 9,306 Total Assets $ — $ — $ 676,626 $ 676,626 Liabilities: Notes $ — $ — $ 206,931 $ 206,931 Certificates Issued by Securitization Trust, at Fair Value — — 26,781 26,781 Convertible Preferred Stock Warrant Liability — — 86,372 86,372 Loan Trailing Fee Liability — — 2,262 2,262 Total Liabilities $ — $ — $ 322,346 $ 322,346 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 634,019 $ 634,019 Loans Held for Sale — — 142,026 142,026 Servicing Assets — — 12,602 12,602 Total Assets $ — $ — $ 788,647 $ 788,647 Liabilities: Notes $ — $ — $ 244,171 $ 244,171 Certificates Issued by Securitization Trust — — 52,168 52,168 Convertible Preferred Stock Warrant Liability — — 149,996 149,996 Loan Trailing Fee Liability — — 2,997 2,997 Total Liabilities $ — $ — $ 449,332 $ 449,332 As Prosper’s Borrower Loans, Loans Held for Sale, Notes, Certificates Issued by Securitization Trust, Convertible Preferred Stock Warrant Liability, servicing rights and loan trailing fee liability do not trade in an active market with readily observable prices, the Company uses significant unobservable inputs to measure the fair value of these assets and liabilities. Financial instruments are categorized in the Level 3 valuation hierarchy based on the significance of unobservable factors in the overall fair value measurement. These fair value estimates may also include observable, actively quoted components derived from external sources. As a result, gains and losses for assets and liabilities within the Level 3 category may include changes in fair value that were attributable to both observable and unobservable inputs. Significant Unobservable Inputs The following tables present quantitative information about the ranges of significant unobservable inputs used for the Company’s Level 3 fair value measurements at September 30, 2020 and December 31, 2019: Range Borrower Loans, Loans Held for Sale and Notes September 30, 2020 December 31, 2019 Discount rate 5.5% - 17.0% 4.4% - 12.2% Default rate 2.3% - 18.1% 2.1% - 18.6% Range Certificates Issued by Securitization Trust September 30, 2020 December 31, 2019 Discount rate 5.1% - 18.5% 4.0% - 15.0% Default rate 3.3% - 16.3% 2.0% - 17.0% Prepayment rate 8.7% - 35.1% 14.5% - 33.0% Range Servicing Assets September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1% Market servicing rate (1) (2) 0.625% - 0.818% 0.625 % (1) Servicing assets associated with loans enrolled in a relief program offered by the Company in response to the COVID-19 pandemic as of September 30, 2020 were measured using a market servicing rate assumption of 81.8 basis points. This rate was estimated using a multiplier consistent with observable market rates for other loan types, applied to the base market servicing rate assumption of 62.5 basis points. (2) Excludes collection fees that would be passed on to a hypothetical third-party servicer. As of September 30, 2020 and December 31, 2019, the market rate for collection fees and non-sufficient fund fees was assumed to b e 7 basis points and 6 basis points, respectively, for a total market servicing rate range of 69.5 - 88.8 basis points and a total market servicing rate of 68.5 basis points, respectively. Range Loan Trailing Fee Liability September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1% At September 30, 2020 and December 31, 2019, the discounted cash flow methodology used to estimate the Notes fair values used the same projected cash flows as the related Borrower Loans. Changes in Level 3 Fair Value Assets and Liabilities on a Recurring Basis The following tables present additional information about Level 3 Borrower Loans, Loans Held for Sale and Notes measured at fair value on a recurring basis (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held For Sale Notes Certificates Issued by Securitization Trust Total Balance at January 1, 2020 $ 634,019 $ 142,026 $ (244,171) $ (52,168) $ 479,706 Purchase of Borrower Loans/Issuance of Notes 97,406 949,529 (97,303) — 949,632 Principal repayments (259,210) (72,885) 114,050 16,608 (201,437) Borrower Loans sold to third parties (5,637) (754,284) — — (759,921) Other changes (1,084) 943 (24) 390 225 Change in fair value (50,617) (12,886) 20,517 8,389 (34,597) Balance at September 30, 2020 $ 414,877 $ 252,443 $ (206,931) $ (26,781) $ 433,608 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Certificates Issued by Securitization Trust Total Balance at January 1, 2019 $ 263,522 $ 183,788 $ (264,003) $ — $ 183,307 Purchase of Borrower Loans/Issuance of Notes 390,089 1,809,133 (128,152) (51,595) 2,019,475 Transfers in (Transfers out) 147,773 (147,773) — — — Principal repayments (221,379) (46,109) 126,721 8,445 (132,322) Borrower Loans sold to third parties (3,412) (1,564,904) — — (1,568,316) Other changes 331 921 538 (351) 1,439 Change in fair value (35,955) (3,412) 17,171 5,937 (16,259) Balance at September 30, 2019 $ 540,969 $ 231,644 $ (247,725) $ (37,564) $ 487,324 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held For Sale Notes Certificates Issued by Securitization Trust Total Balance at July 1, 2020 $ 457,487 $ 216,243 $ (209,987) $ (31,571) $ 432,172 Purchase of Borrower Loans/Issuance of Notes 31,742 327,407 (32,260) — 326,889 Principal repayments (79,658) (29,809) 36,943 6,733 (65,791) Borrower Loans sold to third parties (1,383) (262,502) — — (263,885) Other changes (926) 164 233 49 (480) Change in fair value 7,615 940 (1,860) (1,992) 4,703 Balance at September 30, 2020 $ 414,877 $ 252,443 $ (206,931) $ (26,781) $ 433,608 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Certificates Issued by Securitization Trust Total Balance at July 1, 2019 $ 606,799 $ 114,962 $ (253,425) $ (44,090) $ 424,246 Purchase of Borrower Loans/Issuance of Notes 41,460 647,896 (41,439) — 647,917 Principal repayments (87,348) (19,580) 40,993 4,173 (61,762) Borrower Loans sold to third parties (1,526) (511,596) — — (513,122) Other changes 240 832 (65) 252 1,259 Change in fair value (18,656) (870) 6,211 2,101 (11,214) Balance at September 30, 2019 $ 540,969 $ 231,644 $ (247,725) $ (37,564) $ 487,324 The following tables present additional information about Level 3 Servicing Assets measured at fair value on a recurring basis for the three and nine month periods ending September 30, 2020 and 2019 (in thousands): Servicing Assets Fair Value at January 1, 2020 $ 12,602 Additions 3,945 Less: Changes in fair value (7,241) Fair Value at September 30, 2020 $ 9,306 Servicing Assets Fair Value at January 1, 2019 $ 14,687 Additions 9,237 Derecognition (1,049) Less: Changes in fair value (9,939) Fair Value at September 30, 2019 $ 12,936 Servicing Assets Fair Value at July 1, 2020 $ 10,073 Additions 1,242 Less: Changes in fair value (2,009) Fair Value at September 30, 2020 $ 9,306 Servicing Assets Fair Value at July 1, 2019 $ 13,387 Additions 2,859 Less: Changes in fair value (3,310) Fair Value at September 30, 2019 $ 12,936 The following tables present additional information about the Level 3 Convertible Preferred Stock Warrant Liability measured at fair value on a recurring basis for the three and nine month periods ending September 30, 2020 and 2019 (in thousands): Convertible Preferred Stock Balance as of January 1, 2020 $ 149,996 Change in fair value (63,624) Balance as of September 30, 2020 $ 86,372 Convertible Preferred Stock Balance as of January 1, 2019 $ 143,679 Issuance of Stock Warrants 17,553 Change in fair value (8,890) Balance as of September 30, 2019 $ 152,342 Convertible Preferred Stock Balance as of July 1, 2020 $ 74,998 Change in fair value 11,374 Balance as of September 30, 2020 $ 86,372 Convertible Preferred Stock Balance as of July 1, 2019 $ 166,559 Change in fair value (14,217) Balance as of September 30, 2019 $ 152,342 Loan Trailing Fee The fair value of the Loan Trailing Fee represents the present value of the expected monthly Loan Trailing Fee payments, which takes into consideration certain assumptions related to expected prepayment rates and default rates using a discounted cash flow model. The assumptions used are the same as those used for the valuation of Servicing Assets, as described below. The following tables present additional information about the Level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis for the three and nine month periods ending September 30, 2020 and 2019 (in thousands): Loan Trailing Fee Liability Balance at January 1, 2020 $ 2,997 Issuances 938 Cash Payment of Loan Trailing Fee (1,867) Change in Fair Value 194 Balance at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Balance at January 1, 2019 $ 3,118 Issuances 2,063 Cash Payment of Loan Trailing Fee (1,744) Change in Fair Value (156) Balance at September 30, 2019 $ 3,281 Loan Trailing Fee Liability Balance at July 1, 2020 $ 2,403 Issuances 313 Cash Payment of Loan Trailing Fee (596) Change in Fair Value 142 Balance at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Balance at July 1, 2019 $ 3,249 Issuances 766 Cash Payment of Loan Trailing Fee (446) Change in Fair Value (288) Balance at September 30, 2019 $ 3,281 Significant Recurring Level 3 Fair Value Input Sensitivity Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Borrower Loans and Loans Held for Sale are presented in the following table (in thousands, except percentages). Borrower Loans and Loans Held for Sale September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 667,320 $ 776,045 Weighted-average discount rate 9.57 % 7.00 % Weighted-average default rate 12.50 % 12.63 % Fair value resulting from: 100 basis point increase in discount rate $ 661,563 $ 768,924 200 basis point increase in discount rate $ 655,937 $ 761,971 Fair value resulting from: 100 basis point decrease in discount rate $ 673,214 $ 783,344 200 basis point decrease in discount rate $ 679,249 $ 790,823 Fair value resulting from: 10 percent increase in default rate $ 660,416 $ 765,894 20 percent increase in default rate $ 653,543 $ 756,007 Fair value resulting from: 10 percent decrease in default rate $ 674,253 $ 786,541 20 percent decrease in default rate $ 681,220 $ 797,065 Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Notes are presented in the following table (in thousands, except percentages). Notes September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 206,931 $ 244,171 Weighted-average discount rate 10.50 % 6.43 % Weighted-average default rate 12.90 % 13.68 % Fair value resulting from: 100 basis point increase in discount rate $ 205,143 $ 241,927 200 basis point increase in discount rate $ 203,396 $ 239,737 Fair value resulting from: 100 basis point decrease in discount rate $ 208,761 $ 246,471 200 basis point decrease in discount rate $ 210,635 $ 248,828 Fair value resulting from: 10 percent increase in default rate $ 204,777 $ 240,958 20 percent increase in default rate $ 202,634 $ 237,831 Fair value resulting from: 10 percent decrease in default rate $ 209,093 $ 247,489 20 percent decrease in default rate $ 211,266 $ 250,817 Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Certificates Issued by Securitization Trust are presented in the following table (in thousands, except percentages). Certificates Issued by Securitization Trust September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 26,781 $ 52,168 Weighted-average discount rate 12.78 % 9.59 % Weighted-average default rate 12.10 % 10.12 % Weighted-average prepayment rate 20.03 % 21.41 % Fair value resulting from: 100 basis point increase in discount rate $ 26,560 $ 51,813 200 basis point increase in discount rate $ 26,345 $ 51,466 Fair value resulting from: 100 basis point decrease in discount rate $ 27,007 $ 52,533 200 basis point decrease in discount rate $ 27,240 $ 52,909 Fair value resulting from: 10 percent increase in default rate $ 25,330 $ 48,986 20 percent increase in default rate $ 23,878 $ 45,926 Fair value resulting from: 10 percent decrease in default rate $ 28,222 $ 55,369 20 percent decrease in default rate $ 29,665 $ 58,613 Fair value resulting from: 10 percent increase in prepayment rate $ 26,815 $ 52,085 20 percent increase in prepayment rate $ 26,852 $ 52,008 Fair value resulting from: 10 percent decrease in prepayment rate $ 26,763 $ 52,253 20 percent decrease in prepayment rate $ 26,749 $ 52,340 Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Servicing Assets is presented in the following table (in thousands, except percentages). Servicing Assets September 30, 2020 December 31, 2019 Fair value, using the following assumptions $ 9,306 $ 12,602 Weighted-average market servicing rate 0.634 % 0.625 % Weighted-average prepayment rate 20.13 % 20.99 % Weighted-average default rate 13.13 % 12.67 % Fair value resulting from: Market servicing rate increase of 0.025% $ 8,746 $ 11,825 Market servicing rate decrease of 0.025% $ 9,865 $ 13,387 Fair value resulting from: Applying a 1.1 multiplier to prepayment rate $ 9,124 $ 12,348 Applying a 0.9 multiplier to prepayment rate $ 9,489 $ 12,868 Fair value resulting from: Applying a 1.1 multiplier to default rate $ 9,176 $ 12,377 Applying a 0.9 multiplier to default rate $ 9,435 $ 12,840 These sensitivities are hypothetical and should be evaluated with care. The effect on fair value of a variation in assumptions generally cannot be determined because the relationship of the change in assumptions to the fair value may not be linear. Additionally, the impact of a variation in a particular assumption on the fair value is calculated while holding other assumptions constant. In reality, changes in one factor may lead to changes in other factors, which could impact the above hypothetical effects. Assets and Liabilities Not Recorded at Fair Value The following table presents the fair value hierarchy for assets, and liabilities not recorded at fair value (in thousands): September 30, 2020 Carrying Amount Level 1 Inputs Level 2 Inputs Level 3 Inputs Balance at Fair Value Assets: Cash and Cash Equivalents $ 45,898 $ 45,898 $ — $ — $ 45,898 Restricted Cash 135,826 — 135,826 — 135,826 Accounts Receivable 533 — 533 — 533 Total Assets $ 182,257 $ 45,898 $ 136,359 $ — $ 182,257 Liabilities: Accounts Payable and Accrued Liabilities $ 14,600 $ — $ 14,600 $ — $ 14,600 Payable to Investors 95,887 — 95,887 — 95,887 Notes Issued by Securitization Trust 192,829 — 193,713 — 193,713 Warehouse Lines 226,784 — 226,267 — 226,267 Total Liabilities $ 530,100 $ — $ 530,467 $ — $ 530,467 December 31, 2019 Carrying Amount Level 1 Inputs Level 2 Inputs Level 3 Inputs Balance at Fair Value Assets: Cash and Cash Equivalents $ 64,635 $ 64,635 $ — $ — $ 64,635 Restricted Cash 155,773 — 155,773 — 155,773 Accounts Receivable 1,695 — 1,695 — 1,695 Total Assets $ 222,103 $ 64,635 $ 157,468 $ — $ 222,103 Liabilities: Accounts Payable and Accrued Liabilities $ 19,937 $ — $ 19,937 $ — $ 19,937 Payable to Investors 101,092 — 101,092 — 101,092 Notes Issued by Securitization Trust 347,662 — 353,028 — 353,028 Warehouse Lines 131,583 — 131,090 — 131,090 Total Liabilities $ 600,274 $ — $ 605,147 $ — $ 605,147
Prosper Funding LLC
Entity Information [Line Items]
Fair Value of Assets and Liabilities	Fair Value of Assets and Liabilities Prosper Funding has elected to record certain financial instruments at fair value on the balance sheet. Prosper Funding classifies Borrower Loans, Loans Held for Sale and Notes as financial instruments and assesses their fair value each on a quarterly basis for financial statement presentation purposes. Gains and losses on these financial instruments are shown separately on the condensed consolidated statements of operations. At September 30, 2020 and December 31, 2019, the discounted cash flow methodology used to estimate the Notes fair values used the same projected cash flows as the related Borrower Loans. As demonstrated in the table below, the fair value adjustments for Borrower Loans were largely offset by the fair value adjustments of the Notes due to the borrower payment dependent design of the Notes and because the principal balances of the Borrower Loans approximated the principal balances of the Notes. Assets and liabilities carried at fair value on the balance sheets are classified among three levels based on the observability of the inputs used to determine fair value: Level 1 — The valuation is based on quoted prices in active markets for identical instruments. Level 2 — The valuation is based on observable inputs such as quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation methodologies for which all significant assumptions are observable in the market. Level 3 — The valuation is based on unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the instrument. Level 3 valuations are typically performed using pricing models, discounted cash flow methodologies, or similar methodologies, which incorporate management’s own estimates of assumptions that market participants would use in pricing the instrument or valuations that require significant management judgment or estimation. Fair values of assets or liabilities are determined based on the fair value hierarchy, which requires an entity to maximize the use of quoted prices and observable inputs and to minimize the use of unobservable inputs when measuring fair value. Various valuation methodologies are utilized, depending on the nature of the financial instrument, including the use of market prices for identical or similar instruments, or discounted cash flow models. When possible, active and observable market data for identical or similar financial instruments are utilized. Alternatively, fair value is determined using assumptions that management believes a market participant would use in pricing the asset or liability. Prosper Funding did not transfer any assets or liabilities in or out of Level 3 for the nine months ended September 30, 2020 or 2019. Financial Instruments Recorded at Fair Value The fair value of the Borrower Loans and Notes are estimated using discounted cash flow methodologies based upon a set of valuation assumptions. The primary cash flow assumptions used to value such Borrower Loans and Notes include default and prepayment rates derived primarily from historical performance and discount rates that reflect estimates of the rates of return that investors would require when investing in financial instruments with similar characteristics. The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): September 30, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 208,044 $ 208,044 Servicing Assets — — 11,265 11,265 Total Assets $ — $ — $ 219,309 $ 219,309 Liabilities: Notes $ — $ — $ 206,931 $ 206,931 Loan Trailing Fee Liability — — 2,262 2,262 Total Liabilities $ — $ — $ 209,193 $ 209,193 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 245,137 $ 245,137 Servicing Assets — — 14,888 14,888 Total Assets $ — $ — $ 260,025 $ 260,025 Liabilities: Notes $ — $ — $ 244,171 $ 244,171 Loan Trailing Fee Liability — — 2,997 2,997 Total Liabilities $ — $ — $ 247,168 $ 247,168 As Prosper Funding’s Borrower Loans, Notes, Servicing Assets and loan trailing fee liability do not trade in an active market with readily observable prices, Prosper Funding uses significant unobservable inputs to measure the fair value of these assets and liabilities. Financial instruments are categorized in the Level 3 valuation hierarchy based on the significance of unobservable factors in the overall fair value measurement. These fair value estimates may also include observable, actively quoted components derived from external sources. As a result, the realized and unrealized gains and losses for assets and liabilities within the Level 3 category may include changes in fair value that were attributable to both observable and unobservable inputs. Significant Unobservable Inputs The following tables present quantitative information about the significant unobservable inputs used for Prosper Funding’s Level 3 fair value measurements at the dates presented: Range Borrower Loans and Notes September 30, 2020 December 31, 2019 Discount rate 7.2% - 17.0% 4.4% - 12.1% Default rate 2.6% - 16.85% 2.4% - 17.7% Range Servicing Assets September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1% Market servicing rate (1) (2) 0.625% - 0.818% 0.625 % (1) Servicing assets associated with loans enrolled in a relief program offered by the Company in response to the COVID-19 pandemic as of September 30, 2020 were measured using a market servicing rate assumption of 81.8 basis points. This rate was estimated using a multiplier consistent with observable market rates for other loan types, applied to the base market servicing rate assumption of 62.5 basis points. (2) Excludes collection fees that would be passed on to a hypothetical third-party servicer. As of September 30, 2020 and December 31, 2019, the market rate for collection fees and non-sufficient fund fees was assumed to be 7 b asis points and 6 basis points, respectively, for a total market servicing rate range of 69.5 - 88.8 basis points and a total market servicing rate o f 68.5 basis po ints, respectively. Range Loan Trailing Fee Liability September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1% Changes in Level 3 Fair Value Assets and Liabilities on a Recurring Basis The following tables present additional information about Level 3 Borrower Loans, Loans Held for Sale and Notes measured at fair value on a recurring basis for three months ended September 30, 2020 and 2019 (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at January 1, 2020 $ 245,137 $ — $ (244,171) $ 966 Originations 97,406 949,529 (97,303) 949,632 Principal repayments (112,034) — 114,051 2,017 Borrower Loans sold to third parties (2,111) (949,529) — (951,640) Other changes (23) — (25) (48) Change in fair value (20,331) — 20,517 186 Balance at September 30, 2020 $ 208,044 $ — $ (206,931) $ 1,113 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at January 1, 2019 $ 263,522 $ — $ (264,003) $ (481) Originations 127,522 1,809,133 (128,152) 1,808,503 Principal repayments (123,014) — 126,721 3,707 Borrower Loans sold to third parties (2,578) (1,809,133) — (1,811,711) Other changes (226) — 538 312 Change in fair value (17,508) — 17,171 (337) Balance at September 30, 2019 $ 247,718 $ — $ (247,725) $ (7) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at July 1, 2020 $ 211,775 $ — $ (209,986) $ 1,789 Originations 31,742 327,407 (32,260) 326,889 Principal repayments (36,438) — 36,943 505 Borrower Loans sold to third parties (547) (327,407) — (327,954) Other changes (276) — 232 (44) Change in fair value 1,788 — (1,860) (72) Balance at September 30, 2020 $ 208,044 $ — $ (206,931) $ 1,113 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at July 1, 2019 $ 254,070 $ — $ (253,425) $ 645 Originations 41,460 647,896 (41,439) 647,917 Principal repayments (40,600) — 40,993 393 Borrower Loans sold to third parties (855) (647,896) — (648,751) Other changes (26) — (65) (91) Change in fair value (6,331) — 6,211 (120) Balance at September 30, 2019 $ 247,718 $ — $ (247,725) $ (7) The following tables present additional information about Level 3 Servicing Assets recorded at fair value (in thousands): Servicing Assets Fair Value at January 1, 2020 $ 14,888 Additions 5,034 Less: Changes in fair value (8,657) Fair Value at September 30, 2020 $ 11,265 Servicing Assets Fair Value at January 1, 2019 $ 15,550 Additions 10,232 Less: Changes in fair value (10,562) Fair Value at September 30, 2019 $ 15,220 Servicing Assets Fair Value at July 1, 2020 $ 12,063 Additions 1,632 Less: Changes in fair value (2,430) Fair Value at September 30, 2020 $ 11,265 Servicing Assets Fair Value at July 1, 2019 $ 15,461 Additions 3,436 Less: Changes in fair value (3,677) Fair Value at September 30, 2019 $ 15,220 Loan Trailing Fee Liability The fair value of the Loan Trailing Fee Liability represents the present value of the expected monthly Loan Trailing Fee payments, which takes into consideration certain assumptions related to expected prepayment rates and default rates using a discounted cash flow model. The assumptions used are the same as those used for the valuation of Servicing Assets, as described below. The following tables present additional information about Level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis (in thousands): Loan Trailing Fee Liability Fair Value at January 1, 2020 $ 2,997 Issuances 938 Cash payment of Loan Trailing Fee (1,867) Change in fair value 194 Fair Value at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Fair Value at January 1, 2019 $ 3,118 Issuances 2,063 Cash payment of Loan Trailing Fee (1,744) Change in fair value (156) Fair Value at September 30, 2019 $ 3,281 Loan Trailing Fee Liability Balance at July 1, 2020 $ 2,403 Issuances 313 Cash payment of Loan Trailing Fee (596) Change in fair value 142 Fair Value at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Balance at July 1, 2019 $ 3,249 Issuances 766 Cash payment of Loan Trailing Fee (446) Change in fair value (288) Fair Value at September 30, 2019 $ 3,281 Significant Recurring Level 3 Fair Value Asset and Liability Input Sensitivity Key economic assumptions are used to compute the fair value of Borrower Loans. The sensitivity of the fair value to immediate changes in assumptions at September 30, 2020 and December 31, 2019 for Borrower Loans are presented in the following table (in thousands, except percentages). Borrower Loans September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 208,044 $ 245,137 Weighted-average discount rate 10.50 % 6.43 % Weighted-average default rate 12.90 % 13.68 % Fair value resulting from: 100 basis point increase in discount rate $ 206,249 $ 242,888 200 basis point increase in discount rate 204,495 240,691 Fair value resulting from: 100 basis point decrease in discount rate $ 209,881 $ 247,442 200 basis point decrease in discount rate 211,763 249,805 Fair value resulting from: 10 percent increase in default rate $ 205,891 $ 241,930 20 percent increase in default rate 203,749 238,807 Fair value resulting from: 10 percent decrease in default rate $ 210,205 $ 248,453 20 percent decrease in default rate 212,377 251,777 Key economic assumptions are used to compute the fair value of Notes. The sensitivity of the fair value to immediate changes in assumptions at September 30, 2020 and December 31, 2019 for Notes funded through the Note Channel are presented in the following table (in thousands, except percentages). Notes September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 206,931 $ 244,171 Weighted-average discount rate 10.50 % 6.43 % Weighted-average default rate 12.90 % 13.68 % Fair value resulting from: 100 basis point increase in discount rate $ 205,143 $ 241,927 200 basis point increase in discount rate 203,396 239,737 Fair value resulting from: 100 basis point decrease in discount rate $ 208,761 $ 246,471 200 basis point decrease in discount rate 210,635 248,828 Fair value resulting from: 10 percent increase in default rate $ 204,777 $ 240,958 20 percent increase in default rate 202,634 237,831 Fair value resulting from: 10 percent decrease in default rate $ 209,093 $ 247,489 20 percent decrease in default rate 211,266 250,817 Key economic assumptions are used to compute the fair value of Servicing Assets. The sensitivity of the current fair value to immediate changes in assumptions at September 30, 2020 and December 31, 2019 for Servicing Assets are presented in the following table (in thousands, except percentages). Servicing Assets September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 11,265 $ 14,888 Weighted-average market servicing rate 0.634 % 0.625 % Weighted-average prepayment rate 20.13 % 20.99 % Weighted-average default rate 13.13 % 12.67 % Fair value resulting from: Market servicing rate increase of 0.025% $ 10,588 $ 13,966 Market servicing rate decrease of 0.025% 11,943 15,811 Fair value resulting from: Applying a 1.1 multiplier to prepayment rate $ 11,045 $ 14,583 Applying a 0.9 multiplier to prepayment rate 11,488 15,197 Fair value resulting from: Applying a 1.1 multiplier to default rate $ 11,109 $ 14,618 Applying a 0.9 multiplier to default rate 11,422 15,165 These sensitivities are hypothetical and should be evaluated with care. The effect on fair value of a variation in assumptions generally cannot be determined because the relationship of the change in assumptions to the fair value may not be linear. Additionally, the impact of a variation in a particular assumption on the fair value is calculated while holding other assumptions constant. In reality, changes in one factor may lead to changes in other factors, which could impact the above hypothetical effects.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill Prosper’s goodwill balance of $36.4 million at December 31, 2019 did not change during the nine months ended September 30, 2020. The Company did not record goodwill impairment expense for the nine months ended September 30, 2020 and 2019. Other Intangible Assets The following table presents the detail of other intangible assets subject to amortization as of the following date (dollars in thousands): September 30, 2020 Gross Carrying Value Accumulated Amortization Net Carrying Value Remaining Useful Life (In Years) Developed technology $ 3,060 $ (3,060) $ — — User base and customer relationships 5,050 (4,495) 555 4.6 Brand name 60 (60) — — Total Intangible Assets subject to amortization $ 8,170 $ (7,615) $ 555 Prosper’s intangible asset balance w as $0.6 million and $0.7 million at September 30, 2020 and December 31, 2019, respectively. The user base and customer relationships intangible assets are being amortized on an accelerated basis over a three Amortization expense for the three months ended September 30, 2020 and 2019 was $0.1 million and $0.1 million, respectively. Amortization expense for the nine months ended September 30, 2020 and 2019 was $0.2 million and $0.2 million, respectively. Estimated amortization of purchased intangible assets for future periods is as follows (in thousands): Year Ending December 31, 2020 (remainder thereof) $ 55 2021 172 2022 136 2023 107 2024 85 Total $ 555

Other Liabilities

Other Liabilities	9 Months Ended
	Sep. 30, 2020
Other Liabilities [Abstract]
Other Liabilities	Other Liabilities Other Liabilities consist of the following (in thousands): September 30, 2020 December 31, 2019 Operating lease liabilities $ 14,505 $ 17,507 PPP loan 8,484 — Loan trailing fee 2,262 2,997 Deferred income tax liability 507 405 Deferred revenue 90 241 Other 370 576 Total Other Liabilities $ 26,218 $ 21,726 Additionally, disclosures around the operating lease liabilities are included in Note 16.

Debt

Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt	Debt PWIT Warehouse Trust Agreements Prosper’s consolidated VIEs, PWIT and PWIIT (together, “Warehouse VIEs”), each entered into an agreement (together, “Warehouse Agreements”) with certain lenders for committed revolving lines of credit (“Warehouse Lines”) during 2019 and 2018. In connection with the Warehouse Agreements, the Warehouse VIEs each entered into a security agreement with a bank as administrative agent and a national banking association as collateral trustee and paying agent. Proceeds under the Warehouse Lines may only be used to purchase certain unsecured consumer loans and related rights and documents from Prosper and to pay fees and expenses related to the Warehouse Lines. Both Warehouse VIEs are consolidated because Prosper is the primary beneficiary of the VIEs. The creditors of the Warehouse Lines have no recourse to the general credit of Prosper. Additionally, the assets of the VIEs can be used only to settle obligations of the VIEs. The loans held in the Warehouse VIEs are included in Loans Held for Sale, at Fair Value and Warehouse Lines are in Warehouse Lines in the condensed consolidated balance sheets. Both Warehouse Agreements contain the same certain covenants including restrictions on each Warehouse VIE's ability to incur indebtedness, pledge assets, merge or consolidate and enter into certain affiliate transactions. Each Warehouse Agreement also requires Prosper to maintain a minimum tangible net worth of $25 million, minimum net liquidity of $15 million and a maximum leverage ratio of 5:1. Tangible net worth is defined as the sum of (i) (A) Convertible Preferred Stock, (B) total Stockholders’ Deficit and (C) Convertible Preferred Stock Warrant Liability, less the sum of (ii) (A) goodwill and (B) intangible assets. Net liquidity is defined as the sum of cash, cash equivalents and Available for Sale Investments. The leverage ratio is defined as the ratio of total consolidated indebtedness other than non-recourse securitization indebtedness, non-recourse or limited recourse warehouse indebtedness and borrower dependent notes, to tangible net worth. As of September 30, 2020, Prosper was in compliance with the covenants under each Warehouse Agreement. PWIT Warehouse Line On January 19, 2018, through PWIT, Prosper entered into a Warehouse Agreement for a Warehouse Line. Effective June 12, 2018, the Warehouse Agreement was amended. The amendments included increasing the committed line of credit from $100 million to $200 million, extending the term of the PWIT Warehouse Line (including the final maturity date), amending the monthly unused commitment fee and reducing the rate at which the PWIT Warehouse Line bears interest. Subsequently the Warehouse Agreement was amended on June 20, 2019 to extend the facility, to reduce the interest rate and unused commitment fee and to expand the eligibility criteria for unsecured consumer loans that can be financed through the PWIT Warehouse Line. Under the amended agreement, proceeds of loans made under the PWIT Warehouse Line may be borrowed, repaid and reborrowed until the earlier of June 20, 2021 and at the occurrence of any accelerated amortization event or event of default. Repayment of any outstanding proceeds will be made over the 24 month period ending June 20, 2023, excluding the occurrence of any accelerated amortization event or event of default. Under the amended agreement, the PWIT Warehouse Line bears interest at a rate of LIBOR plus 2.9% and has an advance rate of 89%. Additionally, the PWIT Warehouse Line bears a monthly unused commitment fee of 0.50% per annum on the undrawn portion available under the PWIT Warehouse Line. As of September 30, 2020, Prosper had $100.3 million in debt and accrued interest outstanding under the PWIT Warehouse Line. This debt is secured by an aggregate outstanding principal balance of $117.1 million included in “Loans Held for Sale, at Fair Value” on the condensed consolidated balance sheets. At September 30, 2020 the undrawn portion available under the Warehouse Line was $99.7 million . Prosper incurred $1.8 million of deferred debt issuance costs, which are included in “Prepaids and Other Assets” and amortized to interest expense over the term of the revolving arrangement. Prosper purchased a swaption to limit the Company's exposure to increases in LIBOR. The swaption is recorded on the consolidated balance sheet at fair value in Prepaids and Other Assets. Any changes in the fair value are recorded in the Change in Fair Value of Financial Instruments, Net on the Consolidated Statement of Operations. The fair value of the swaption was not material at September 30, 2020. PWIIT Warehouse Line On March 28, 2019, through PWIIT, Prosper entered into a second Warehouse Agreement for a $300 million Warehouse Line with a national banking association different than that of PWIT. Under the PWIIT Warehouse Agreement, proceeds of loans made under the PWIIT Warehouse Line may be borrowed, repaid, and reborrowed until the earlier of March 28, 2021 and at the occurrence of any accelerated amortization event or event of default. Repayment of any outstanding proceeds will be made over the 24 month period ending March 28, 2023, excluding the occurrence of any accelerated amortization event or event of default. Under the agreement, the PWIIT Warehouse Line bears interest at a rate of LIBOR, or the lender's asset-backed commercial paper rate, plus a spread of 2.9%. The spread increases by 0.375% during the first twelve months immediately following the termination of the revolving period with an additional increase of 0.375% one year later. The PWIIT Warehouse Line has an advance rate of 90%. Additionally, the PWIIT Warehouse Line bears a monthly unused commitment fee of 0.50% per annum on the undrawn portion available under the PWIIT Warehouse Line. As of September 30, 2020, Prosper had $126.5 million in debt and accrued interest outstanding under the PWIIT Warehouse Line. This debt is secured by an aggregate outstanding principal balance of $141.4 million included in Loans Held for Sale, at Fair Value on the Consolidated Balance Sheets. At September 30, 2020 the undrawn portion available under the PWIIT Warehouse Line was $173.5 million . Prosper incurred $2.1 million of deferred debt issuance costs, which are included in Prepaids and Other Assets and amortized to interest expense over the term of the revolving arrangement. Paycheck Protection Program Loan The Paycheck Protection Program (“PPP”), established by the Coronavirus Aid, Relief, and Economic Security Act (“CARES Act”) and sponsored by the U.S. Small Business Administration (“SBA”), provides small businesses – sole proprietors, independent contractors, and, with certain industry exceptions, businesses with fewer than 500 employees – the opportunity to apply for a loan of up to $10 million to cover up to 24 weeks (the “covered period”) of payroll costs, including benefits. Funds may also be used to cover interest on mortgage obligations, leases, and utilities incurred or in place before February 15, 2020. PPP loan payments are deferred as described below, and, based on SBA guidance, will be forgiven as long as (i) loan proceeds are used for covered expenses, (ii) full-time employee headcount is maintained during the eight-week period covered by the PPP loan and (iii) compensation for employees who earned less than $100,000 on an annualized basis in 2019 is not reduced by more than 25% during the covered period. For purposes of calculating maximum loan eligibility, payroll costs per employee are capped at $100,000 on an annualized basis. Due to anticipated high PPP participation rates, the SBA expects that not more than 40% of any forgiven loan amount may be for non-payroll costs. In April 2020, the Company obtained an $8.4 million loan under the PPP. The loan accrues interest at one percent per annum and has a two-year term through April 2022. Payments under the loan are deferred until the earlier of (a) August 2021 or (b) receipt of forgiveness of the loan from the lender and the SBA. The Company used the PPP Loan proceeds to cover payroll costs, rent and utilities in accordance with the relevant terms and conditions of the CARES Act. As of September 30, 2020, principal and interest outstanding under the PPP loan totaled $8.5 million and is included in Other Liabilities on the accompanying condensed consolidated balance sheet.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per ShareProsper computes Net Income (Loss) Per Share in accordance with ASC Topic 260, Earnings Per Share (“ASC Topic 260”). Under ASC Topic 260, basic Net Income (Loss) Per Share is computed by dividing net income (loss) available to common stockholders by the weighted average number of common shares outstanding for the period and excludes the effects of any potentially dilutive securities. Prosper computes its earnings (loss) per share using the two-class method in ASC Topic 260. The two-class method allocates earnings that otherwise would have been available to common shareholders to holders of participating securities. Management considers all series of our Convertible Preferred Stock to be participating securities due to their rights to participate in dividends with Common Stock. As such, earnings allocated to these participating securities, which include participation rights in undistributed earnings, are subtracted from net income to determine total undistributed earnings to be allocated to common stockholders. All participating securities are excluded from basic weighted-average common shares outstanding. Prior to any conversion to common shares, each series of Prosper’s Convertible Preferred Stock was entitled to participate on an if-converted basis in distributions of earnings, when and if declared by the board of directors, that were made to common stockholders and consequently, these shares were considered participating securities. During the periods ended September 30, 2020 and 2019, certain shares issued as a result of the early exercise of stock options which are subject to a repurchase right by PMI were entitled to receive non-forfeitable dividends during the vesting period and consequently, are considered participating securities. The weighted average shares used in calculating basic and diluted Net Income (Loss) Per Share excludes certain shares that are disclosed as outstanding shares in the Consolidated Balance Sheets because such shares are restricted as they were associated with options that were early exercised and continue to remain unvested. Basic and diluted income (loss) per share was calculated as follows for the periods presented (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net (Loss) Income $ (2,025) $ 10,769 $ 36,746 $ (12,514) Plus: return on share purchase 2,381 — 2,381 — Less: net income allocated to participating securities (255) (7,994) (28,814) — Net income (loss) available to common stockholders $ 101 $ 2,775 $ 10,313 $ (12,514) Denominator: Weighted average shares used in computing net income (loss) per share - basic 68,485,173 70,606,805 68,465,046 70,532,641 Effect of dilutive securities: Stock options 14,902,171 1,939,105 50,778,284 — Convertible preferred stock warrants 213,264,845 213,264,845 213,264,845 — Weighted average shares used in computing diluted net income (loss) per share - diluted 296,652,189 285,810,755 332,508,175 70,532,641 Net income (loss) per share - basic $ — $ 0.04 $ 0.15 $ (0.18) Net income (loss) per share - diluted $ — $ 0.01 $ 0.03 $ (0.18) The following common stock equivalents were excluded from the computation of diluted net income (loss) per share for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (shares) (shares) (shares) (shares) Excluded securities: Convertible preferred stock issued and outstanding, excluding shares held by consolidated VIE 181,761,442 214,637,925 200,261,761 214,637,925 Stock options issued and outstanding 58,390,141 73,211,425 22,127,694 73,029,965 Warrants issued and outstanding 1,080,349 1,080,349 1,080,349 1,080,349 Series E-1 convertible preferred stock warrants — 35,544,141 — 35,544,141 Series F convertible preferred stock warrants — 177,720,704 — 177,720,704 Total common stock equivalents excluded from diluted net income (loss) per common share computation 241,231,932 502,194,544 223,469,804 502,013,084

Convertible Preferred Stock, Wa

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit	9 Months Ended
	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit	Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit Convertible Preferred Stock and Warrants Under PMI’s amended and restated certificate of incorporation, preferred stock is issuable in series, and the Board of Directors is authorized to determine the rights, preferences, and terms of each series. On July 13, 2020, the Company established Prosper Grantor Trust (“PGT”), a revocable grantor trust administered by an independent trustee, with the intention of contributing assets to PGT for the benefit of PMI employees in the event of a change in control through an Eligible Employee Retention Plan. PGT was determined to be a VIE and PMI was determined to be its primary beneficiary due to the fact that the Company, through its role as the grantor, has both (a) the power to direct the activities that most significantly affect the VIE’s economic performance, including its funding decisions and investment strategy, and (b) the obligation to absorb losses that could be potentially significant to the economic performance of the VIE by virtue of the Company’s requirement to fund PGT in the event that it is unable to meet its obligations to PMI’s employees. PMI also maintains a contingent call liability on PGT’s assets in the event of a bankruptcy. As a result, PGT is fully consolidated into PMI’s consolidated financial statements. On July 21, 2020, PGT entered into a Stock Transfer Agreement with a PMI investor to purchase 34,670,420 shares of Series A Convertible Preferred Stock and 16,577,495 shares of Series B Convertible Preferred Stock for nominal consideration. Upon execution of the Stock Transfer Agreement, these shares were purchased by a consolidated VIE of the Company, and thus the difference between the fair value of the repurchased stock and the purchase price is included in Convertible Preferred Stock Held by Consolidated VIE on PMI’s accompanying consolidated balance sheet as of September 30, 2020. These shares remain outstanding for legal purposes and retain their voting rights, but are excluded from the earnings per share calculation. The number of authorized, issued and outstanding shares, their par value and liquidation preference for each series of convertible preferred stock as of September 30, 2020 are disclosed in the table below (amounts in thousands except share and par value amounts): Convertible Preferred Stock Par Value Authorized Shares Outstanding and Issued Shares Liquidation Preference, Outstanding Shares Series A $ 0.01 68,558,220 66,428,185 * $ 19,160 Series A-1 $ 0.01 24,760,915 22,515,315 45,031 Series B $ 0.01 35,775,880 35,127,160 * 21,190 Series C $ 0.01 24,404,770 24,404,770 70,075 Series D $ 0.01 23,888,640 23,888,640 165,000 Series E-1 $ 0.01 35,544,141 — — Series E-2 $ 0.01 16,858,078 — — Series F $ 0.01 177,720,707 3 — Series G $ 0.01 37,249,497 37,249,497 50,000 Total 444,760,848 209,613,570 $ 370,456 * Series A and Series B Convertible Preferred Stock totals are inclusive of 34,670,420 and 16,577,495 shares, respectively, held by PGT, a consolidated VIE. Dividends Dividends on shares of the Series A, Series B, Series C, Series D, Series E-1, Series E-2, Series F and Series G convertible preferred stock are payable only when, as, and if declared by the Board of Directors. No dividends will be paid with respect to the common stock until any declared dividends on the Series A, Series B, Series C, Series D, Series E-1, Series E-2, Series F, and Series G convertible preferred stock have been paid or set aside for payment to the Series A, Series B, Series C, Series D, Series E-1, Series E-2, Series F, and Series G convertible preferred stockholders. After payment of any such dividends, any additional dividends or distributions will be distributed among all holders of common stock and preferred stock in proportion to the number of shares of common stock that would be held by each such holder if all shares of preferred stock were converted to common stock at the then-effective conversion rate. The Series A-1 convertible preferred shares have no dividend rights. To date, no dividends have been declared on any of PMI’s preferred stock or common stock. Conversion Under the terms of PMI’s amended and restated certificate of incorporation, the holders of preferred stock have the right to convert such preferred stock into common stock at any time. In addition, all preferred stock automatically converts into common stock (i) immediately prior to the closing of an initial public offering that values Prosper at least at $2 billion and that results in aggregate proceeds to Prosper of at least $100 million or (ii) upon a written request from the holders of at least 60% of the voting power of the outstanding preferred stock (on an as-converted basis), provided that (i) the Series A-1 convertible preferred stock shall not be converted without at least 14% of the voting power of the outstanding Series A-1 convertible preferred stock; (ii) the Series D shall not be converted without at least 60% of the voting power of the outstanding Series D; (iii) the Series E-1 and Series E-2 shall not be converted without at least 60% of the voting power of the outstanding Series E-1 and Series E-2, voting together as a single class; (iv) the Series F shall not be converted without at least 60% of the voting power of the outstanding Series F, and (v) the shares of Series G Preferred Stock will not be automatically converted unless the holders of at least 60% of the outstanding shares of Series G Preferred Stock approve such conversion. In addition, if a holder of the Series A convertible preferred stock has converted any of the Series A convertible preferred stock, then all of such holder’s shares of Series A-1 convertible preferred stock also will be converted upon a liquidation event. In lieu of any fractional shares of common stock to which a holder would otherwise be entitled, PMI shall pay such holder cash in an amount equal to the fair market value of such fractional shares, as determined by its Board of Directors. At present, each of the Series A, Series B, Series C, Series D, Series E-1, Series E-2, and Series F convertible preferred stock converts into PMI common stock at a 1:1 ratio. The Series A-1 convertible preferred stock converts into common stock at a 1,000,000:1 ratio and the Series G convertible preferred stock converts into common stock at a 1:1.36 ratio. The Series G convertible preferred stock conversion ratio reflects the Series G true-up that occurred at end of the vesting period for the Series E-2 and Series F Preferred Stock warrants. For the Series G true-up, the conversion price of the Series G Convertible Preferred Stock was reduced to a number equal to the Series G Preferred Stock original issuance price, divided by the quotient obtained by dividing the Series G true-up amount by the total number of Series G Preferred Stock issued as of the Series G closing date. The Series G true-up amount means the aggregate number of shares of Series G Preferred Stock that would have been issued to the purchasers of the Series G Preferred Stock on the Series G closing date, if warrants to purchase shares of Series E-2 Preferred Stock or Series F Preferred Stock that were exercisable or exercised as of the true-up time (end of vesting period) had been exercisable or exercised as of such Series G closing date. Liquidation Rights PMI’s convertible preferred stock has been classified as temporary equity on the condensed consolidated balance sheets. The preferred stock is not redeemable; however, in the event of a voluntary or involuntary liquidation, dissolution, change in control or winding up of PMI, holders of the convertible preferred stock may have the right to receive its liquidation preference under the terms of PMI’s certificate of incorporation. Each holder of Series E-1, Series E-2, and Series F convertible preferred stock is entitled to receive prior and in preference to any distribution of proceeds from a liquidation event to the holders of Series A, Series B, Series C, Series D, Series G and Series A-1 convertible preferred stock or common stock, an amount per share for (i) each share of Series E-1 convertible preferred stock equal to the sum of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share, (ii) each share of Series E-2 convertible preferred stock equal to the sum of two-thirds the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share, and (iii) each share of Series F convertible preferred stock equal to the sum of two-thirds of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share. After the payment or setting aside for payment to the holders of Series E-1, Series E-2, and Series F convertible preferred stock, each holder of Series A, Series B, Series C and Series D, Series E-2, Series F, and Series G convertible preferred stock is entitled to receive, on a pari passu basis, prior to and in preference to any distribution of proceeds from a liquidation event to the holders of Series A-1 convertible preferred stock or common stock, (i) an amount per share for each share of Series E-2 and Series F convertible preferred stock equal to the sum of one-third of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share, and (ii) an amount per share for each share of Series A, Series B, Series C, Series D and Series G convertible preferred stock equal to the sum of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share. After the payment or setting aside for payment to the holders of Series A, Series B, Series C, Series D, Series E-1, Series E-2, Series F, and Series G convertible preferred stock, the holders of Series A-1 convertible preferred stock are entitled to receive, prior and in preference to any distribution of proceeds to the holders of common stock, an amount per share for each such share of Series A-1 convertible preferred stock equal to the sum of the liquidation preference specified for such share and all declared but unpaid dividends, if any, on such share. After the payment or setting aside for payment to the holders of Series A, Series B, Series C, Series D, Series E-1, Series E-2, Series F, Series G, and Series A-1 convertible preferred stock, the entire remaining proceeds legally available for distribution will be distributed pro rata to the holders of Series A convertible preferred stock and common stock in proportion to the number of shares of common stock held by them assuming the Series A convertible preferred stock has been converted into shares of common stock at the then effective conversion rate, provided that the maximum aggregate amount per share of Series A convertible preferred stock which the holders of Series A convertible preferred stock shall be entitled to receive is three times the original issue price for the Series A convertible preferred stock. At present, the liquidation preferences are equal to $0.29 per share for the Series A convertible preferred stock, $2.00 per share for the Series A-1 convertible preferred stock, $0.60 per share for the Series B convertible preferred stock, $2.87 per share for the Series C convertible preferred stock, $6.91 per share for the Series D convertible preferred stock, $0.84 per share for the Series E-1 convertible preferred stock, $0.84 per share for the Series E-2 convertible preferred stock, $0.84 per share for the Series F convertible preferred stock and $1.34 per share for the Series G convertible preferred stock. Voting Each holder of shares of convertible preferred stock is entitled to the number of votes equal to the number of shares of common stock into which such shares of convertible preferred stock could be converted and has voting rights and powers equal to the voting rights and powers of the common stock. The holders of convertible preferred stock and the holders of common stock vote together as a single class (except with respect to certain matters that require separate votes or as required by law), and are entitled to notice of any stockholders’ meeting in accordance with the Bylaws of PMI. Convertible Preferred Stock Warrant Liability Series E-1 Warrants In connection with the Settlement and Release Agreement dated November 17, 2016 among PMI, its wholly owned subsidiary Prosper Funding LLC (“PFL”) and Colchis, on December 16, 2016, PMI issued the First Series E-1 Warrant. The Second Series E-1 Warrant for an additional 15,277,006 shares of Series E-1 convertible preferred stock was granted on the signing of the Consortium Purchase Agreement (as defined in Note 15) on February 27, 2017. The warrants expire ten years from the dat e of issuance. For the three months ended September 30, 2020 and 2019, Prosper recogni zed $2.5 million of expense and $1.8 million of income, respectively, from the re-measurement of the fair value of the warrants. For the nine months ended September 30, 2020 and 2019, Prosper recognized $10.3 million and $0.7 million of income, respectively, from the re-measurement of the fair value of the warrants. The income or expense resulted from the remeasurement of the fair value of the warrants is recorded through Change in Fair Value of Convertible Preferred Stock Warrants on the condensed consolidated statements of operations. To determine the fair value of the Series E-1 Warrants, the Company first determined the value of a share of a Series E-1 Convertible Preferred Stock. To determine the fair value of the Convertible Preferred Stock, the Company first derived the business enterprise value (“BEV”) of the Company using a variety of valuation methods, including discounted cash flow models and market based methods, as deemed appropriate under the circumstances applicable at the valuation date. Once the Company determined an estimated BEV, the option pricing method ("OPM") was used to allocate the BEV to the various classes of our equity, including our preferred stock. The concluded per share value for the Series E-1 Convertible Preferred Stock was utilized as an input to the Black-Scholes option pricing model. The Company determined the fair value of the outstanding Series E-1 Warrants utilizing the following assumptions as of the following dates: September 30, 2020 December 31, 2019 Volatility 66.0 % 46.0 % Risk-free interest rate 0.20 % 1.60 % Expected term (in years) 2.75 2.75 Dividend yield — % — % The above assumptions were determined as follows: Volatility . The volatility is derived from historical volatilities of several unrelated publicly listed peer companies over a period approximately equal to the term of the warrant as the Company has limited information on the volatility of its preferred stock since there is currently no trading history. When making the selections of industry peer companies to be used in the volatility calculation, the Company considered the size, operational, and economic similarities to the Company’s principal business operations. Risk-Free Interest Rate . The risk-free interest rate is based on the U.S. Treasury yield in effect as of the period end date and for zero coupon U.S. Treasury notes with maturities approximately equal to the term of the warrant. Expected Term . The expected term is the period of time for which the warrants are expected to be outstanding. Dividend Yield . The expected dividend assumption is based on the Company’s current expectations about the Company’s anticipated dividend policy. Series F Warrants In connection with the Consortium Purchase Agreement (as described in Note 15), PMI issued warrants to purchase up to 177,720,706 shares of PMI's Series F convertible preferred stock at $0.01 per share. For the three months ended September 30, 2020 and 2019, Prosper recognized $8.9 million of expense and $12.4 million of income, respectively, from the re-measurement of the fair value of the warrants. For the nine months ended September 30, 2020 and 2019, Prosper recognized $53.3 million and $8.1 million of income, respectively, from the re-measurement of the fair value of the warrants. The income or expense resulting from changes in the fair value of the warrant is recorded through Change in Fair Value of Convertible Preferred Stock Warrants on the condensed consolidated statements of operations . To determine the fair value of the Series F Warrants, the Company first determined the value of a share of a Series F Convertible Preferred Stock. To determine the fair value of the Convertible Preferred Stock, the Company first derived the BEV using valuation methods, including a combination of methods, as deemed appropriate under the circumstances applicable at the valuation date. Once the Company determined an estimated BEV, the OPM was used to allocate the BEV to the various classes of Prosper's equity, including our preferred stock. The concluded per share value for the Series F Convertible Preferred Stock warrants utilized the Black-Scholes option pricing model. The Company determined the fair value of the outstanding Series F Warrants utilizing the following assumptions as of the following dates: September 30, 2020 December 31, 2019 Volatility 66.0 % 46.0 % Risk-free interest rate 0.20 % 1.60 % Expected term (in years) 2.75 2.75 Dividend yield — % — % The above assumptions were determined using the same criteria described above for the Series E-1 Warrants. The combined activity of the Convertible Preferred Stock Warrant Liability for the nine months ended September 30, 2020 and 2019 are as follows (in thousands): Warrant Activity Balance at January 1, 2020 $ 149,996 Change in fair value (63,624) Balance at September 30, 2020 $ 86,372 Warrant Activity Balance at January 1, 2019 $ 143,679 Warrants vested 17,553 Change in fair value (8,890) Balance at September 30, 2019 $ 152,342 Common Stock PMI, through its Amended and Restated Certificate of Incorporation, is the sole issuer of common stock and related options, restricted stock units ("RSUs") and warrants. On February 16, 2016, PMI amended and restated its Certificate of Incorporation to, among other things, effect a 5-for-1 forward stock split. On September 20, 2017, PMI further amended its Amended and Restated Certificate of Incorporation to increase the number of shares of common stock authorized for issuance. The total number of shares of stock which PMI has the authority to issue is 1,069,760,848, consisting of 625,000,000 shares of common stock, $0.01 par value per share, and 444,760,848 shares of preferred stock, $0.01 par value per share. As of September 30, 2020 , 69,794,521 shares of common stock were issued and 68,858,586 shares of common stock were outstanding. As of December 31, 2019, 69,387,836 shares of common stock were issued and 68,451,901 shares of common stock were outstanding. Each holder of common stock is entitled to one vote for each share of common stock held. Common Stock Issued upon Exercise of Stock Options

Share Based Incentive Plan and

Share Based Incentive Plan and Compensation	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Share Based Incentive Plan and Compensation	Share Based Incentive Plan and Compensation PMI grants equity awards primarily through its Amended and Restated 2005 Stock Option Plan (the “2005 Plan”), which was approved as amended and restated by its stockholders on December 1, 2010; and its 2015 Equity Incentive Plan, which was approved by its stockholders on April 7, 2015 and subsequently amended by an Amendment No. 1, Amendment No. 2 and Amendment No. 3, which were approved by PMI's stockholders effective as of February 15, 2016, May 31, 2016, and September 5, 2018 respectively (as amended, the “2015 Plan”). In March 2015, the 2005 Plan expired, except that any awards granted under the 2005 Plan prior to its expiration remain in effect pursuant to their terms. Stock Option Reprice On May 3, 2016, the Compensation Committee of the Board of Directors of PMI approved a stock option repricing program (the “2016 Repricing”), authorizing PMI’s officers to reprice certain outstanding stock options held by employees and directors that have exercise prices above the current fair market value of PMI’s common stock. The repricing was effected on May 16, 2016 for eligible directors and employees located in the United States and on May 19, 2016 for eligible employees located in Israel. On March 17, 2017, the Compensation Committee of the Board of Directors of PMI approved a stock option repricing program (the “2017 Repricing”), authorizing PMI’s officers to reprice certain outstanding stock options held by employees and directors that have exercise prices above the current fair market value of PMI’s common stock. The 2017 Repricing was effected on March 17, 2017 for eligible directors and employees. On August 11, 2020, the Compensation Committee of the Board of Directors of PMI approved a stock option repricing program (the “2020 Repricing” and together with the 2016 Repricing and the 2017 Repricing, the “Repricings”) authorizing PMI’s officers to reprice certain outstanding stock options held by employees and directors that have exercise prices above the current fair market value of PMI’s common stock. The repricing was effected on August 11, 2020 for eligible directors and employees. Prosper believes that the Repricings will encourage the continued service of valued employees and directors, and motivate such service providers to perform at high levels, both of which are critical to Prosper’s continued success. Prosper expects to incur additional stock based compensation charges as a result of the Repricings. The financial statement impact of the above Repricings was $0.4 million for both the three and nine months ended September 30, 2020, and unamortized Repricings expense (net of forfeitures) of $0.1 million will be recognized over the remaining weighted average vesting period of 2.1 years as of September 30, 2020. Stock Option Activity Stock option activity under the 2005 Plan and 2015 Plan is summarized for the nine months ended September 30, 2020 below: Options Issued and Outstanding Weighted- Average Exercise Price Balance as of January 1, 2020 76,236,757 $ 0.31 Options issued 8,308,000 0.08 Options exercised (406,685) 0.02 Options forfeited (6,724,169) 0.34 Options expired (3,351,580) 0.13 Balance as of September 30, 2020 74,062,323 0.02 Options vested and expected to vest as of September 30, 2020 59,837,480 0.02 Options vested and exercisable at September 30, 2020 50,344,747 0.02 Other Information Regarding Stock Options The weighted-average remaining life for options outstanding as of September 30, 2020 was 7.27 years. The fair value of options granted to employees is estimated on the grant date using the Black-Scholes option valuation model. This valuation model for stock-based compensation expense requires Prosper to make assumptions and judgments about the variables used in the calculation, including the fair value of PMI’s common stock, the expected term (the period of time that the options granted are expected to be outstanding), the volatility of PMI’s common stock, a risk-free interest rate, and expected dividends. Given the absence of a publicly traded market, Prosper considered numerous objective and subjective factors to determine the fair value of PMI’s common stock at each grant date. These factors included, but were not limited to: (i) contemporaneous valuations of common stock performed by unrelated third-party specialists, (ii) the prices for PMI’s preferred stock sold to outside investors, (iii) the rights, preferences and privileges of PMI’s preferred stock relative to PMI’s common stock, (iv) the lack of marketability of PMI’s common stock, (v) developments in the business, (vi) secondary transactions of PMI’s common and preferred shares, and (vii) the likelihood of achieving a liquidity event, such as an initial public offering or a merger or acquisition of Prosper, given prevailing market conditions. As PMI’s stock is not publicly traded, volatility for stock options is based on an average of the historical volatilities of the common stock of several entities with characteristics similar to those of Prosper. The expected term assumptions were determined based on the vesting terms, exercise terms and contractual lives of the options using the simplified method. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for periods corresponding with the expected life of the option. Prosper uses an expected dividend yield of zero as it does not anticipate paying any dividends in the foreseeable future. Prosper also estimates forfeitures of unvested stock options. Expected forfeitures are based on Prosper’s historical experience. To the extent actual forfeitures differ from the estimates, the difference will be recorded as a cumulative adjustment in the period estimates are revised. No compensation cost is recorded for options that do not vest. The fair value of PMI’s stock option awards granted during the three and nine months ended September 30, 2020 and 2019 was estimated at the date of grant using the Black-Scholes model with the following average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Volatility of common stock 57.32 % 46.72 % 52.66 % 46.72 % Risk-free interest rate 0.37 % 1.57 % 0.51 % 2.24 % Expected life 6.0 years 6.0 years 6.0 years 5.9 years Dividend yield — % — % — % — % Restricted Stock Unit Activity For the nine months ended September 30, 2020, PMI did not grant any RSUs to employees. In previous reporting periods, PMI granted certain employees RSUs that are subject to three-year or four-year vesting terms and the occurrence of a liquidity event. The following table summarizes the number of PMI’s outstanding RSUs and their weighted-average grant date fair value for the nine months ended September 30, 2020: Number of Shares Weighted-Average Grant Date Fair Value Unvested - January 1, 2020 4,803,141 $ 0.95 Forfeited (142,000) $ 2.18 Unvested - September 30, 2020 4,661,141 $ 0.91 The following table presents the amount of stock-based compensation related to stock-based awards granted to employees recognized in Prosper’s condensed consolidated statements of operations for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Origination and servicing $ 53 $ 73 $ 124 $ 377 Sales and marketing 25 71 51 216 General and administrative 708 844 1,508 3,245 Total stock-based compensation $ 786 $ 988 $ 1,683 $ 3,838 Prosper capitalized stock-based compensation as internal-use software and website development costs of $0.1 million for both the three months ended September 30, 2020 and 2019, and $0.2 million and $0.3 million for the nine months ended September 30, 2020 and 2019, respectively. As of September 30, 2020 , the unamortized stock-based compensation expense adjusted for forfeiture estimates related to our employees’ unvested stock-based awards was approximately $2.3 million, which will be recognized over the remaining weighted-average vesting period of approximately 1.9 years.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Income Taxes	Income Taxes For the three months ended September 30, 2020 and 2019, Prosper reco gnized $34 thousand and $29 thousand of income tax expense, respectively. For the nine months ended September 30, 2020 and 2019, Prosper recognized $102 thousand and $87 thousand of income tax expense, respectively. The income tax expense relates to state income tax expense and th e amortization of tax deductible goodwill which gives rise to an indefinite-lived deferred tax liability. No other income tax expense or benefit was recorded for the three and nine month periods ended September 30, 2020 and September 30, 2019 due to a full valuation allowance recorded against the Company’s deferred tax assets . Management assesses the available positive and negative evidence to estimate if sufficient future taxable income will be generated to utilize our existing deferred tax assets. On the basis of this evaluation, it is not more likely than not that our deferred tax assets will be realized and therefore a full valuation allowance has been recorded.
Prosper Funding LLC
Entity Information [Line Items]
Income Taxes	Income TaxesProsper Funding incurred no income tax provision for the nine months ended September 30, 2020 and September 30, 2019. Prosper Funding is a U.S. disregarded entity and its income and loss are included in the income tax reporting of its parent, PMI. Since PMI is in a cumulative loss position, is not currently subject to income taxes, and has fully reserved against its deferred tax asset, the net effective tax rate for Prosper Funding is 0%.

Consortium Purchase Agreement

Consortium Purchase Agreement	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Consortium Purchase Agreement	Consortium Purchase Agreement On February 27, 2017, Prosper entered into a series of agreements (the “Consortium Purchase Agreement”) with a consortium of investors (the “Consortium”), pursuant to which the Consortium agreed to purchase Borrower Loans in an aggregate principal amount of up to $5.0 billion (including certain loans purchased by one of the investors prior to the date of the Consortium Purchase Agreement). PFL was obligated to offer for purchase minimum monthly volumes of eligible loans to the Consortium, for the Consortium to elect to purchase. The obligation to offer for purchase minimum monthly volumes of eligible loans and the related vesting ended upon the expiration of the Consortium Purchase Agreement in May 2019. In connection with the Consortium Purchase Agreement, PMI issued to the Consortium three warrants to purchase up to an aggregate 177,720,706 shares of PMI’s Series F Preferred Stock at an exercise price of $0.01 per share (the “Warrant Shares”). The Consortium's right to exercise these Series F Warrants was subject to monthly vesting and was fully vested in May 2019. On vesting of the Series F Warrants, Prosper recorded a liability as Convertible Preferred Stock Warrant Liability on the condensed consolidated balance sheets at fair value and a corresponding amount as Fair Value of Warrants Vested on Sale of Borrower Loans on the condensed consolidated statement of operations. Subsequent changes in the fair value of the vested warrants are recorded in Change in Fair Value of Convertible Preferred Stock Warrants on the condensed consolidated statement of operations. Additionally, in connection with the execution of the Consortium Purchase Agreement, certain previously issued rebates were settled by an issuance of vested Series F Convertible Preferred Stock Warrants. The difference in fair value of these warrants over the cash settlement price is recorded in Change in Fair Value of Convertible Preferred Stock Warrants on the condensed consolidated statement of operations. Through its expiration in May 2019, $3.3 billion in loans were acquired and 177.7 million warrants vested under the Consortium Purchase Agreement. In addition to the $3.3 billion of loans acquired above, warrants vested on signing of the Consortium Purchase Agreement were issued to settle certain rebates on $0.3 billion of whole loan purchases by members of the Consortium prior to the signing of the Consortium Purchase Agreement. This $0.3 billion also reduced the up to $5.0 billion aggregate amount under the Consortium Purchase Agreement.

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	Leases Prosper has operating leases for corporate offices and datacenters. These leases have remaining lease terms of one year to six years. Some of the lease agreem ents include options to extend the lease term for up to an additional five years. Rental expense under operating lease arrangements was $1.2 million and $1.4 million for the three months ended September 30, 2020 and 2019, respectively. Rental expense under operating lease arrangements was $4.2 million and $4.1 million for the nine months ended September 30, 2020 and 2019, respectively. Additionally, Prosper subleases certain leased office space to third parties when it determines there is excess leased capacity. Sublease income from operating lease arrangements was $0.1 million and $0.2 million for the three months ended September 30, 2020 and 2019, respectively. Sublease income from operating lease arrangements was $0.4 million and $0.6 million for the nine months ended September 30, 2020 and 2019, respectively. Operating Lease Right-of-Use (“ROU”) Assets The following table summarizes the operating lease right-of-use assets as of September 30, 2020, which are included in “Property and Equipment, Net” on the condensed consolidated balance sheets. September 30, 2020 Gross Carrying Value Accumulated Amortization Net Carrying Value ROU Assets - Office buildings $ 15,694 $ 5,796 $ 9,898 ROU Assets - Other 290 6 284 Total right-of-use assets subject to amortization $ 15,984 $ 5,802 $ 10,182 The Company identified certain impairment triggers related to its ROU assets in the second quarter of 2020, primarily due to the non-renewal of certain sublease agreements and the time expected to find new subtenants. As a result of impairment testing performed on these ROU assets, the Company recorded an impairment charge of $0.2 million for the three months ended June 30, 2020. No impairment charge was recorded for the three months ended September 30, 2020. Lease Liabilities Future maturities of operating lease liabilities as of September 30, 2020 were as follows (in thousands). The present value of the future minimum lease payments represent our lease liabilities as of September 30, 2020 and are included in " Other Liabilities Minimum Lease Payments Remainder of 2020 $ 1,338 2021 5,279 2022 5,121 2023 1,562 2024 871 Thereafter 1,820 Total future minimum lease payments $ 15,991 Less imputed interest (1,486) Present value of future minimum lease payments $ 14,505 Because the rate implicit in each lease is not readily determinable, we use our incremental borrowing rate to determine the present value of the lease payments. Other information related to leases was as follows ($ in thousands): September 30, 2020 Cash paid for operating leases year-to-date $ 3,996 Right of use assets obtained in exchange for new operating lease obligations $ 290 Weighted average remaining lease term (in years) 3.55 years Weighted average discount rate 5.50 %

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Commitments and Contingencies	Commitments and Contingencies In the normal course of its operations, Prosper becomes involved in various legal actions. Prosper maintains provisions it considers to be adequate for such actions. Prosper does not believe it is probable that the ultimate liability, if any, arising out of any such matters will have a material effect on Prosper's financial condition, results of operations or cash flows. Operating Commitments Prosper entered into an agreement with WebBank, under which all Borrower Loans originated through the marketplace are made by WebBank under its bank charter. Pursuant to the agreement, the marketing fee that Prosper receives in connection with the origination of each loan is partially reduced by an amount (the “Designated Amount”) calculated as a percentage of the principal amount of such loan based on the aggregate principal amount of loans originated for the applicable month. To the extent the aggregate Designated Amount for all loans originated during any month is less than $143,500, Prosper is required to pay WebBank an amount equal to such deficiency. Accordingly, the minimum fee for the remaining three months of 2020 is $0.4 million. The minimum fees are $1.7 million and $0.1 million for the years 2021 and 2022, respectively. Additionally, under the agreement with WebBank, Prosper is required to maintain minimum net liquidity of $15.0 million at all times during the term of the agreement. Net liquidity is defined as the sum of Cash, Cash Equivalents and Available for Sale Investments. Violation of this covenan t can result in termination of the contract with WebBank. As of September 30, 2020, Prosper was in compliance with the covenant. Loan Purchase Commitments Prosper entered into an agreement with WebBank to purchase $12.9 million of Borrower Loans that WebBank originated during the last two business days of the quarter ended September 30, 2020. Prosper will purchase these Borrower Loans within the first three business days of the quarter ending December 31, 2020. Repurchase Obligation Under the terms of the loan purchase agreements between Prosper and investors that participate in the Whole Loan Channel, Prosper may, in certain circumstances, become obligated to repurchase a Borrower Loan from an investor. Generally, these circumstances include the occurrence of verifiable identity theft, the failure to properly follow loan listing or bidding protocols or a violation of the applicable federal, state or local lending laws. Prosper recognizes a liability at fair value for the repurchase obligation when the Borrower Loans are sold. The fair value of the repurchase obligation is estimated based on historical experience. Repurchased Borrower Loans associated with violations of federal, state or local lending laws or verifiable identity theft are written off at the time of repurchase. The maximum potential amount of future payments associated with this obligation is the outstanding balances of the Borrower Loans issued through the Whole Loan Channel, which at September 30, 2020 is $2.4 billion. Pros per has accrued $0.3 million and $0.4 million as of September 30, 2020 and December 31, 2019, respectively, in regard to this obligation. Regulatory Contingencies Prosper accrues for contingencies when a loss from such contingencies is probable and the amount of loss can be reasonably estimated. In determining whether a loss is probable and if it is possible to quantify the amount of the estimated loss, Prosper reviews and evaluates its litigation and regulatory matters on at least a quarterly basis in light of potentially relevant factual and legal developments. If Prosper determines that an unfavorable outcome is not probable or that the amount of a loss cannot be reasonably estimated, Prosper does not accrue for a potential litigation loss. If an unfavorable outcome is probable and Prosper can estimate a range of outcomes, an amount is recorded which management considers to be the best estimate within the range of potential losses that are both probable and estimable; however, if management cannot quantify the amount of the estimated loss, then the low end of the range of the potential losses is recorded. SEC Inquiry In April 2017, we became aware of an error in the annualized net return and seasoned annualized net return numbers displayed to Note investors. Prosper was advised by the SEC that it was investigating whether violations of federal securities laws had occurred in connection with the error. On April 19, 2019, the SEC accepted an offer of settlement from PFL to resolve the matter. Under the settlement, the SEC alleged a violation of Section 17(a)(2) of the Securities Act and ordered PFL to cease and desist from any future violations of that provision. PFL neither admitted nor denied any wrongdoing, and agreed to pay a civil monetary penalty of $3.0 million. The penalty of $3.0 million was paid in full in April 2019. West Virginia Matter In January 2018, the Attorney General of the State of West Virginia (the “Attorney General”) initiated discussions regarding certain acts and practices of PMI and PFL that the Attorney General asserts may have violated the West Virginia Consumer Credit and Protection Act (the “Consumer Act”), to which Prosper responded with such information as was requested by the Attorney General. Following a period of more than a year with limited to no communication, in February 2020, Prosper received a proposed Assurance of Discontinuance (an “AOD”) from the Attorney General requesting that, without in any way admitting that any of its prior practices were in violation of the Consumer Act, Prosper agree to certain terms and conditions regarding its past and potential future conduct of its business with respect to customers in West Virginia, including a release by the Attorney General of any claims it may have related to the matters identified in the AOD. Prosper is evaluating and intends to discuss the proposed terms in the AOD with the Attorney General. We cannot predict the outcome of the matter and any potential fines or penalties, if any, that may arise from the matter. Further, we are unable to estimate a range of outcomes and as a result no accrual has been made. No loans have been originated through the Prosper platform to West Virginians since June 2016.
Prosper Funding LLC
Entity Information [Line Items]
Commitments and Contingencies	Commitments and Contingencies Operating Commitments Prosper entered into an agreement with WebBank, under which all Borrower Loans originated through the marketplace are made by WebBank under its bank charter. Pursuant to the agreement, the marketing fee that Prosper receives in connection with the origination of each loan is partially reduced by an amount (the “Designated Amount”) calculated as a percentage of the principal amount of such loan based on the aggregate principal amount of loans originated for the applicable month. To the extent the aggregate Designated Amount for all loans originated during any month is less than $143,500, Prosper is required to pay WebBank an amount equal to such deficiency. Accordingly, the minimum fee for the remaining three months of 2020 is $0.4 million . The minimum fees are $1.7 million and $0.1 million for the years 2021 and 2022, respectively. Additionally, under the agreement with WebBank, Prosper is required to maintain minimum net liquidity of $15 million at all times during the term of the agreement. Net liquidity is defined as the sum of Cash, Cash Equivalents and Available for Sale Investments. Violation of this covenant can result in termination of the contract with WebBank. As of September 30, 2020, we were in compliance with the covenant. Loan Purchase Commitments Under the terms of Prosper Funding’s agreement with WebBank, Prosper Funding is committed to purchase $12.9 million of Borrower Loans that WebBank originated during the last two business days of the quarter ended September 30, 2020. Prosper Funding will purchase these Borrower Loans within the first three business days of the quarter ending December 31, 2020. Repurchase Obligation Under the terms of the loan purchase agreements between Prosper Funding and investors that participate in the Whole Loan Channel, Prosper Funding may, in certain circumstances, become obligated to repurchase a Borrower Loan from an investor. Generally, these circumstances include the occurrence of verifiable identity theft, the failure to properly follow loan listing or bidding protocols, or a violation of the applicable federal, state, or local lending laws. The fair value of the indemnification and repurchase obligation is estimated based on historical experience. Prosper Funding recognizes a liability for the repurchase and indemnification obligation when the Borrower Loans are issued. Indemnified or repurchased Borrower Loans associated with violations of federal, state, or local lending laws or verifiable identity theft are written off at the time of repurchase or at the time an indemnification payment is made. The maximum potential amount of future payments associated under this obligation is the outstanding balances of the Borrower Loans issued through the Whole Loan Channel, which as of September 30, 2020 is $2.9 billion. Prosp er Funding has acc rued $0.3 million and $0.4 million as of September 30, 2020 and December 31, 2019, respectively, in regard to this obligation. Regulatory Contingencies Prosper accrues for contingencies when a loss from such contingencies is probable and the amount of loss can be reasonably estimated. In determining whether a loss is probable and if it is possible to quantify the amount of the estimated loss, Prosper reviews and evaluates its litigation and regulatory matters on at least a quarterly basis in light of potentially relevant factual and legal developments. If Prosper determines that an unfavorable outcome is not probable or that the amount of a loss cannot be reasonably estimated, Prosper does not accrue for a potential litigation loss. If an unfavorable outcome is probable and Prosper can estimate a range of outcomes, we record the amount we consider to be the best estimate within the range of potential losses that are both probable and estimable; however, if we cannot quantify the amount of the estimated loss, then we record the low end of the range of those potential losses. SEC Inquiry In April 2017, we became aware of an error in the annualized net return and seasoned annualized net return numbers displayed to Note investors. Prosper was advised by the SEC that it was investigating whether violations of federal securities laws had occurred in connection with the error. On April 19, 2019, the SEC accepted an offer of settlement from PFL to resolve the matter. Under the settlement, the SEC alleged a violation of Section 17(a)(2) of the Securities Act and ordered PFL to cease and desist from any future violations of that provision. PFL neither admitted nor denied any wrongdoing, and agreed to pay a civil monetary penalty of $3.0 million. The penalty of $3.0 million was paid in full in April 2019. West Virginia Matter In January 2018, the Attorney General of the State of West Virginia (the “Attorney General”) initiated discussions regarding certain acts and practices of PMI and PFL that the Attorney General asserts may have violated the West Virginia Consumer Credit and Protection Act (the “Consumer Act”), to which Prosper responded with such information as was requested by the Attorney General. Following a period of more than a year with limited to no communication, in February 2020, Prosper received a proposed Assurance of Discontinuance (an “AOD”) from the Attorney General requesting that, without in any way admitting that any of its prior practices were in violation of the Consumer Act, Prosper agree to certain terms and conditions regarding its past and potential future conduct of its business with respect to customers in West Virginia, including a release by the Attorney General of any claims it may have related to the matters identified in the AOD. Prosper is evaluating and intends to discuss the proposed terms in the AOD with the Attorney General. We cannot predict the outcome of the matter and any potential fines or penalties, if any, that may arise from the matter. Further, we are unable to estimate a range of outcomes and as a result no accrual has been made. No loans have been originated through the Prosper platform to West Virginians since June 2016.

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Related Parties	Related Parties Since Prosper’s inception, it has engaged in various transactions with its directors, executive officers, and holders of more than 10% of its voting securities, and immediate family members and other affiliates of its directors, executive officers, and 10% stockholders. Prosper believes that all of the transactions described below were made on terms no less favorable to Prosper than could have been obtained from unaffiliated third parties. Prosper’s executive officers, directors who are not executive officers, and certain affiliates participate in its marketplace by placing bids and purchasing Notes and Borrower Loans. The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be affiliates and related parties of Prosper for the three and nine months ended September 30, 2020 and 2019, as well as the Notes and Borrower Loans outstanding as of September 30, 2020 and December 31, 2019 are summarized below (in thousands): Aggregate Amount of Interest Earned on Related Party 2020 2019 2020 2019 Executive officers and management $ 7 $ 6 $ 1 $ 1 Directors (excluding executive officers and management) 41 101 14 13 Total $ 48 $ 107 $ 15 $ 14 Aggregate Amount of Interest Earned on Related Party 2020 2019 2020 2019 Executive officers and management $ 19 $ 17 $ 4 $ 4 Directors (excluding executive officers and management) 272 309 43 37 Total $ 291 $ 326 $ 47 $ 41 Notes Balance as of Related Party September 30, 2020 December 31, 2019 Executive officers and management $ 37 $ 35 Directors (excluding executive officers and management) 549 682 $ 586 $ 717
Prosper Funding LLC
Entity Information [Line Items]
Related Parties	Related Parties Since inception, Prosper Funding has engaged in various transactions with its directors, executive officers, sole member, and immediate family members and other affiliates of its directors, executive officers, and sole member. Prosper Funding believes that all of the transactions described below were made on terms no less favorable to Prosper Funding than could have been obtained from unaffiliated third parties. Prosper Funding’s executive officers and directors who are not executive officers participate in its marketplace by placing bids and purchasing Notes and Borrower Loans. The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be related parties of Prosper Funding for the three and nine months ended September 30, 2020 and 2019 are summarized below (in thousands): Aggregate Purchases Interest Earned Three Months Ended September 30, Three Months Ended September 30, Related Party 2020 2019 2020 2019 Executive officers and management $ 7 $ 6 $ 1 $ 1 Directors (excluding executive officers and management) — — — — Total $ 7 $ 6 $ 1 $ 1 Aggregate Purchases Interest Earned Nine Months Ended September 30, Nine Months Ended September 30, Related Party 2020 2019 2020 2019 Executive officers and management $ 19 $ 17 $ 4 $ 4 Directors (excluding executive officers and management) — — — — Total $ 19 $ 17 $ 4 $ 4 The balance of Notes held by officers and directors who are not executive officers are as follows (in thousands): Notes Balance as of Related Party September 30, 2020 December 31, 2019 Executive officers and management $ 37 $ 35 Directors (excluding executive officers and management) — — $ 37 $ 35

Significant Concentrations

Significant Concentrations	9 Months Ended
	Sep. 30, 2020
Risks and Uncertainties [Abstract]
Significant Concentrations	Significant Concentrations Prosper is dependent on third party funding sources such as banks, asset managers, investment funds and Warehouse Lines to provide the funds to allow WebBank to originate Borrower Loans that the third party funding sources will later purchase. Of all Borrower Loans originated in the three months ended September 30, 2020, two individual parties purchased 26.7% and 15.0% of such loans, and t he Company’s Warehouse VIEs purchased 23.1% of such loans. Of all Borrower Loans originated in the nine months ended September 30, 2020, those same two parties purchas ed 17.7% and 16.4%, respecti vely, of such loans, and the Company’s Warehouse VIEs purchased 21.1% of such loans. For the three months ended September 30, 2019, two parties pu rchased 15.8% and 11.5% of all Borrower Loans originated , and the Company’s Warehouse VIEs purchased 18.8% of such loans. For the nine months ended September 30, 2019, another individual party purchased 11.4% of all Borrower Loans originated, and the Company’s Warehouse VIEs purchased 11.7% of such loans. These purchases reflect that a significant portion of Prosper’s business is dependent on funding through the Whole Loan Channel, through whi ch 91% and 93% of Borrower Loans were originated in the nine months ended September 30, 2020 and 2019, respectively. Prosper receives all of its transaction fee revenue from WebBank. Prosper earns a transaction fee from WebBank for its services in facilitating originations of Borrower Loans issued by WebBank. The rate of the transaction fee for each individual Borrower Loan is based on the term and credit grade of the Borrower Loan. No individual borrower or investor accounted for 10% or more of consolidated net revenue for any of the periods presented .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Marketplace, Inc. (“PMI”) was incorporated in the state of Delaware on March 22, 2005. Except as the context requires otherwise, as used in these notes to the condensed consolidated financial statements of PMI, “Prosper,” “we,” “us,” and “our” refer to PMI and its wholly-owned subsidiaries, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2019. The balance sheet at December 31, 2019 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. The preparation of Prosper’s condensed consolidated financial statements and related disclosures in conformity with US GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in Prosper’s financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions. The accompanying interim condensed consolidated financial statements include the accounts of PMI, its wholly-owned subsidiaries and consolidated variable interest entities (“VIEs”). All intercompany balances have been eliminated in consolidation. Securitization Notes are notes held by certain third party investors pursuant to Prosper’s securitization transactions, and are distinguishable from the borrower payment dependent Notes available to investors through our Note Channel.
Fair Value Measurements	Fair Value Measurements Financial instruments measured at fair value consist principally of Borrower Loans, Loans Held for Sale, Servicing Assets, Notes, Certificates Issued by Securitization Trust and Convertible Preferred Stock Warrant Liability. The estimated fair values of other financial instruments, including Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short-term nature. The estimated fair values of Notes Issued by Securitization Trust and Warehouse Lines do not approximate their carrying values due primarily to differences in the stated and market rates associated with these instruments.
Restricted Cash	Restricted Cash Restricted Cash consists primarily of cash deposits, money market funds and short term certificate of deposit accounts held as collateral as required for long term leases, loan funding and servicing activities, and cash that investors have on our marketplace that has not yet been invested in Borrower Loans or disbursed to the investor.
Borrower Loans, Loans Held for Sale, Notes and Certificates Issued by Securitization Trust	Borrower Loans, Loans Held for Sale, Notes and Certificates Issued by Securitization Trust Borrower Loans are funded either through the Note Channel or through the Whole Loan Channel. Through the Note Channel, Prosper purchases Borrower Loans from WebBank, then issues Notes and holds the Borrower Loans until maturity. The obligation to repay a series of Notes issued through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans funded and Notes issued through the Note Channel are carried on Prosper’s condensed consolidated balance sheets as assets and liabilities, respectively. In 2019, Prosper began refinancing the purchase of Borrower Loans through the Whole Loan Channel through securitization transactions, which issue senior notes, risk retention interests and residual certificates. Associated securitization trusts are deemed consolidated VIEs, and as a result the Borrower Loans held in the securitization trusts are included in “Borrower Loans, at Fair Value”. Senior notes sold to third party investors are included in “Notes Issued by Securitization Trust,” and the risk retention interest and residual certificates held by third party investors are included in “Certificates Issued by Securitization Trust, at Fair Value” on the accompanying condensed consolidated balance sheets. Refer to Note 6 , Securitization for additional disclosures. Prosper uses Warehouse Lines to purchase Loans Held for Sale that may be subsequently contributed to securitization transactions or sold to investors. Loans Held for Sale are included in “Loans Held for Sale, at Fair Value” on the Consolidated Balance Sheets. See Note 10, Debt for more details on Warehouse Lines. Borrower Loans and Loans Held for Sale are purchased from WebBank. Prosper places Borrower Loans and Loans Held for Sale on non-accrual status when they are 120 days past due. When a loan is placed on non-accrual status, Prosper stops accruing interest and reverses all accrued but unpaid interest as of such date. Additionally, Prosper charges-off Borrower Loans and Loans Held for Sale when they are 120 days past due. The fair value of loans 120 or more days past due generally consists of the expected recovery from debt sales in subsequent periods. Prosper has elected the fair value option for Borrower Loans, Loans Held for Sale, Notes, and Certificates Issued by Securitization Trust. Changes in fair value of Borrower Loans funded through the Note Channel are largely offset by the changes in fair value of Notes due to the borrower payment-dependent design of the Notes. Changes in fair value of Borrower Loans held in consolidated securitization trusts are partially offset by changes in fair value of the Certificates Issued by Securitization Trust. Changes in fair value of Loans Held for Sale are recorded through Proper's earnings and Prosper collects interest on Loans Held for Sale. Changes in the fair values of Borrower Loans, Loans Held for Sale, Notes, and Certificates Issued by Securitization Trust are included in “Change in Fair Value of Financial Instruments, Net” on the Consolidated Statements of Operations. Prosper primarily uses a discounted cash flow model to estimate the fair value of Borrower Loans, Loans Held for Sale, Notes, and Certificates Issued by Securitization Trust. The key assumptions used in the valuation include default rates and prepayment rates derived primarily from historical performance, and discount rates based on estimates of the rates of return that investors would require when investing in financial instruments with similar characteristics.
Leases	Leases Management determines if an arrangement is a lease at inception. Operating lease right-of-use (“ROU”) assets and operating lease liabilities are included on the Consolidated Balance Sheets in Property and Equipment, Net and in Other Liabilities, respectively. For certain leases with original terms of twelve months or less, PMI recognizes the lease expense as incurred and does not record ROU assets and lease liabilities. If a contract contains a lease, management evaluates whether it should be classified as an operating or finance lease. Operating lease ROU assets and operating lease liabilities are recognized based on the present value of the future minimum lease payments over the lease term at the commencement date. As most of PMI's leases do not provide an implicit rate, management uses an incremental borrowing rate based on the information available at commencement date in determining the present value of future payments. The operating lease ROU asset also includes any lease payments made and excludes lease incentives and initial direct costs incurred. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term. The operating lease ROU assets are evaluated for impairment utilizing the same impairment model used for Property and Equipment.
Consolidation of Variable Interest Entities	Consolidation of Variable Interest Entities The determination of whether to consolidate a VIE in which we have a variable interest requires a significant amount of analysis and judgment regarding whether we are the primary beneficiary of a VIE due to our holding a controlling financial interest in the VIE. A controlling financial interest in a VIE exists if we have both the power to direct the VIE’s activities that most significantly affect the VIE’s economic performance and a potentially significant economic interest in the VIE. The determination of whether an entity is a VIE considers factors, such as (i) whether the entity’s equity investment at risk is insufficient to allow the entity to finance its activities without additional subordinated financial support and (ii) whether a holder’s equity investment at risk lacks any of the following characteristics of a controlling financial interest: the direct or indirect ability through voting rights or similar rights to make decisions about a legal entity’s activities that have a significant effect on the entity’s success, the obligation to absorb the expected losses of the entity or the right to receive the expected residual returns of the legal entity. Management regularly reviews and reconsiders its previous conclusions regarding the status of an entity as a VIE and whether we are required to consolidate such VIE in the consolidated financial statements.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Standards Adopted by the Company in the Current Year In June 2016, the Financial Accounting Standards Board (“FASB”) amended guidance related to impairment of financial instruments as part of Accounting Standards Update (“ASU”) No. 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments”, which is effective for interim and annual periods beginning after December 15, 2019. Prosper adopted the standard in the first quarter of 2020. For loans accounted for at amortized cost, the guidance replaces the incurred loss impairment methodology with an expected credit loss model for which a company recognizes an allowance based on the estimate of expected credit loss. Because Prosper accounts for Borrower Loans at fair value through net income there was no impact on Prosper loan portfolios upon adoption. For certain available for sale investments, the guidance requires recognition of expected credit losses through recording an allowance for credit losses. The recognition of this allowance is limited to the difference between the security’s amortized cost basis and fair value. The amendments to the available for sale debt securities impairment model did not have a material impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, “Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment.” Prior to ASU No. 2017-04, the goodwill impairment test was a two-step assessment, if indicators of impairment existed. The standard eliminates Step 2 from the goodwill impairment test, which requires a hypothetical purchase price allocation. Instead, entities will record a goodwill impairment charge based on the excess of a reporting unit's carrying amount over its fair value. The standard is effective for interim and annual periods beginning after December 15, 2019 and early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. Prosper adopted the guidance on a prospective basis in the first quarter of 2020, and there was no impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” Entities are no longer required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. ASU No. 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years, but entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. Prosper adopted the guidance in the first quarter of 2020. The guidance only affects disclosures in the notes to the consolidated financial statements and it had no effect on Prosper’s balance sheet or statement of operations. In August 2018, the FASB issued ASU No. 2018-15, “Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract.” This ASU aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. This ASU is effective for fiscal years beginning after December 15, 2019, including interim periods within that fiscal year and early adoption is permitted. The Company adopted the new guidance in the first quarter of 2020, and will prospectively capitalize all eligible costs related to cloud computing arrangements starting January 1, 2020. There was, however, no impact on the Company’s consolidated financial statements for the first nine months of 2020. Accounting Standards Issued, to be Adopted by the Company in Future Periods In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” This ASU simplifies the accounting for income taxes by removing certain exceptions related to the incremental approach for intraperiod tax allocation, the requirement to recognize or derecognize deferred tax liabilities related to equity method investments that are also foreign subsidiaries and the methodology for calculating income taxes in an interim period. The guidance also clarifies and simplifies other aspects of the accounting for income taxes, including a modification in the guidance for franchise taxes that are partially based on income and recognizing deferred taxes for a subsequent step-up in the tax basis of goodwill. This ASU is effective for annual periods beginning after December 15, 2020, including interim periods within those annual periods. Early adoption is permitted, including adoption in an interim period. The Company is currently evaluating the impact this new standard will have on the Company’s consolidated financial statements. In March 2020, the FASB issued ASU No. 2020-04, “Reference Rate Reform (Topic 848),” which provides optional expedients and exceptions for applying GAAP on contract modifications and hedge accounting, in order to ease the financial reporting burdens of the expected market transition from LIBOR and other interbank offered rates to alternative referenced rates, such as the Secured Overnight Financing Rate. This ASU can be adopted after its issuance date through December 31, 2022. The Company is currently evaluating the impact reference rate reform will have on its contracts that reference LIBOR in order to determine whether to adopt this guidance.
Prosper Funding LLC
Entity Information [Line Items]
Basis of Presentation	Basis of Presentation Prosper Funding LLC (“PFL”) was formed in the state of Delaware in February 2012 as a limited liability company with the Prosper Marketplace, Inc. (“PMI”) as its sole equity member. Except as the context otherwise requires, as used in these Notes to the condensed consolidated financial statements of PFL, “Prosper Funding,” “we,” “us,” and “our” refers to PFL and its wholly owned subsidiary, Prosper Depositor LLC, a Delaware limited liability company, on a consolidated basis. The unaudited interim condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“US GAAP”) and disclosure requirements for interim financial information and the requirements of Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by US GAAP for complete financial statements. The unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements and notes thereto for the year ended December 31, 2019. The balance sheet at December 31, 2019 has been derived from the audited financial statements at that date. Management believes these unaudited interim condensed consolidated financial statements reflect all adjustments, consisting of a normal recurring nature, which are necessary for a fair presentation of the results for the interim periods presented. The results of operations for the interim periods are not necessarily indicative of the results that may be expected for the full year or any other interim period. Prosper Funding did not have any items of other comprehensive income or loss for any of the periods presented in the condensed consolidated financial statements as of and for the nine months ended September 30, 2020 and September 30, 2019. The preparation of Prosper Funding's condensed consolidated financial statements and related disclosures in conformity with US GAAP requires management to make judgments, assumptions and estimates that affect the amounts reported in its condensed consolidated financial statements and accompanying notes. Management bases its estimates on historical experience and on various other factors it believes to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of certain assets and liabilities. These judgments, estimates and assumptions are inherently subjective in nature and actual results may differ from these estimates and assumptions, and the differences could be material.
Fair Value Measurements	Fair Value Measurements Financial instruments consist principally of Cash and Cash Equivalents, Restricted Cash, Borrower Loans, Loans Held for Sale, Accounts Receivable, Accounts Payable and Accrued Liabilities, Payable to Investors and Notes. The estimated fair values of Cash and Cash Equivalents, Restricted Cash, Accounts Receivable, Accounts Payable and Accrued Liabilities, and Payable to Investors approximate their carrying values because of their short term nature.
Restricted Cash	Restricted Cash Restricted Cash consists primarily of cash deposits, money market funds and short term certificate of deposit accounts held as collateral as required for long term leases, loan funding and servicing activities, and cash that investors have on our marketplace that has not yet been invested in Borrower Loans or disbursed to the investor.
Borrower Loans, Loans Held for Sale, Notes and Certificates Issued by Securitization Trust	Borrower Loans, Loans Held for Sale and Notes With respect to the Note Channel, Prosper Funding purchases Borrower Loans from WebBank, then issues Notes and holds the Borrower Loans until maturity. The obligation to repay a series of Notes funded through the Note Channel is dependent upon the repayment of the associated Borrower Loan. Borrower Loans and Notes funded through the Note Channel are carried on Prosper Funding’s condensed consolidated balance sheets as assets and liabilities, respectively. Prosper Funding places Borrower Loans and Loans Held for Sale on non-accrual status when they are 120 days past due. When a loan is placed on non-accrual status, Prosper stops accruing interest and reverses all accrued but unpaid interest as of such date. Additionally, Prosper charges-off Borrower Loans and Loans Held for Sale when they are 120 days past due. The fair value of loans 120 days past due generally consists of the expected recovery from debt sales in subsequent periods. Management has elected the fair value option for Borrower Loans, Loans Held for Sale, and Notes. Changes in fair value of Borrower Loans are largely offset by the changes in fair value of Notes due to the borrower payment-dependent design of the Notes. Changes in fair value of Borrower Loans, Loans Held for Sale and Notes are included in “Change in Fair Value of Borrower Loans, Loans Held for Sale and Notes, Net” on the Consolidated Statements of Operations. Prosper Funding primarily uses a discounted cash flow model to estimate the fair value of Borrower Loans, Loans Held for Sale and Notes. The key assumptions used in the valuation include default rates and prepayment rates derived primarily from historical performance and discount rates based on estimates of the rates of return that investors would require when investing in financial instruments with similar characteristics.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Accounting Standards Adopted In The Current Period In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurement (Topic 820); Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” Entities will no longer be required to disclose the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy, but public companies will be required to disclose the range and weighted average used to develop significant unobservable inputs for Level 3 fair value measurements. ASU No. 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019 and for interim periods within those fiscal years, but entities are permitted to early adopt either the entire standard or only the provisions that eliminate or modify the requirements. The guidance only affects disclosures in the notes to the consolidated financial statements and has no effect on Prosper Funding’s balance sheet or statements of operations. Accounting Standards Issued, To Be Adopted By Prosper Funding In Future Periods

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Property and Equipment, Net	Property and Equipment consists of the following at the dates presented (in thousands): September 30, 2020 December 31, 2019 Operating lease right-of-use assets $ 15,984 $ 16,213 Computer equipment 13,558 13,420 Internal-use software and website development costs 32,446 28,904 Office equipment and furniture 2,999 2,999 Leasehold improvements 7,167 7,158 Assets not yet placed in service 4,020 2,445 Property and equipment 76,174 71,139 Less: Accumulated depreciation and amortization (46,591) (39,843) Total Property and Equipment, Net $ 29,583 $ 31,296
Prosper Funding LLC
Entity Information [Line Items]
Property and Equipment, Net	Property and equipment consist of the following (in thousands): September 30, 2020 December 31, 2019 Internal-use software and web site development costs $ 26,437 $ 24,930 Less accumulated depreciation and amortization (19,086) (17,381) Total property and equipment, net $ 7,351 $ 7,549

Borrower Loans, Loans Held fo_2

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value (Tables)	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Aggregate Principal Balances Outstanding and Fair Values of Borrower Loans, Notes and Loans Held for Sale	The aggregate principal balances outstanding and fair values of Borrower Loans, Loans Held for Sale, and Notes as of September 30, 2020 and December 31, 2019, are presented in the following table (in thousands): Borrower Loans Loans Held for Sale Notes September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 Aggregate principal balance outstanding $ 440,460 $ 647,209 $ 260,405 $ 143,261 $ (219,730) $ (250,281) Fair value adjustments (25,583) (13,190) (7,962) (1,235) 12,799 6,110 Fair value $ 414,877 $ 634,019 $ 252,443 $ 142,026 $ (206,931) $ (244,171)
Prosper Funding LLC
Entity Information [Line Items]
Aggregate Principal Balances Outstanding and Fair Values of Borrower Loans, Notes and Loans Held for Sale	The aggregate principal balances outstanding and fair values of Borrower Loans and Notes as of September 30, 2020 and December 31, 2019, are presented in the following table (in thousands): Borrower Loans Notes September 30, 2020 December 31, 2019 September 30, 2020 December 31, 2019 Aggregate principal balance outstanding $ 218,064 $ 248,702 $ (219,730) $ (250,281) Fair value adjustments (10,020) (3,565) 12,799 6,110 Fair value $ 208,044 $ 245,137 $ (206,931) $ (244,171)

Fair Value of Assets and Liab_2

Fair Value of Assets and Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value	The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): September 30, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 414,877 $ 414,877 Loans Held for Sale — — 252,443 252,443 Servicing Assets — — 9,306 9,306 Total Assets $ — $ — $ 676,626 $ 676,626 Liabilities: Notes $ — $ — $ 206,931 $ 206,931 Certificates Issued by Securitization Trust, at Fair Value — — 26,781 26,781 Convertible Preferred Stock Warrant Liability — — 86,372 86,372 Loan Trailing Fee Liability — — 2,262 2,262 Total Liabilities $ — $ — $ 322,346 $ 322,346 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 634,019 $ 634,019 Loans Held for Sale — — 142,026 142,026 Servicing Assets — — 12,602 12,602 Total Assets $ — $ — $ 788,647 $ 788,647 Liabilities: Notes $ — $ — $ 244,171 $ 244,171 Certificates Issued by Securitization Trust — — 52,168 52,168 Convertible Preferred Stock Warrant Liability — — 149,996 149,996 Loan Trailing Fee Liability — — 2,997 2,997 Total Liabilities $ — $ — $ 449,332 $ 449,332
Quantitative Information About Significant Unobservable Inputs	The following tables present quantitative information about the ranges of significant unobservable inputs used for the Company’s Level 3 fair value measurements at September 30, 2020 and December 31, 2019: Range Borrower Loans, Loans Held for Sale and Notes September 30, 2020 December 31, 2019 Discount rate 5.5% - 17.0% 4.4% - 12.2% Default rate 2.3% - 18.1% 2.1% - 18.6% Range Certificates Issued by Securitization Trust September 30, 2020 December 31, 2019 Discount rate 5.1% - 18.5% 4.0% - 15.0% Default rate 3.3% - 16.3% 2.0% - 17.0% Prepayment rate 8.7% - 35.1% 14.5% - 33.0% Range Servicing Assets September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1% Market servicing rate (1) (2) 0.625% - 0.818% 0.625 % (1) Servicing assets associated with loans enrolled in a relief program offered by the Company in response to the COVID-19 pandemic as of September 30, 2020 were measured using a market servicing rate assumption of 81.8 basis points. This rate was estimated using a multiplier consistent with observable market rates for other loan types, applied to the base market servicing rate assumption of 62.5 basis points. (2) Excludes collection fees that would be passed on to a hypothetical third-party servicer. As of September 30, 2020 and December 31, 2019, the market rate for collection fees and non-sufficient fund fees was assumed to b e 7 basis points and 6 basis points, respectively, for a total market servicing rate range of 69.5 - 88.8 basis points and a total market servicing rate of 68.5 basis points, respectively. Range Loan Trailing Fee Liability September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1%
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present additional information about Level 3 Borrower Loans, Loans Held for Sale and Notes measured at fair value on a recurring basis (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held For Sale Notes Certificates Issued by Securitization Trust Total Balance at January 1, 2020 $ 634,019 $ 142,026 $ (244,171) $ (52,168) $ 479,706 Purchase of Borrower Loans/Issuance of Notes 97,406 949,529 (97,303) — 949,632 Principal repayments (259,210) (72,885) 114,050 16,608 (201,437) Borrower Loans sold to third parties (5,637) (754,284) — — (759,921) Other changes (1,084) 943 (24) 390 225 Change in fair value (50,617) (12,886) 20,517 8,389 (34,597) Balance at September 30, 2020 $ 414,877 $ 252,443 $ (206,931) $ (26,781) $ 433,608 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Certificates Issued by Securitization Trust Total Balance at January 1, 2019 $ 263,522 $ 183,788 $ (264,003) $ — $ 183,307 Purchase of Borrower Loans/Issuance of Notes 390,089 1,809,133 (128,152) (51,595) 2,019,475 Transfers in (Transfers out) 147,773 (147,773) — — — Principal repayments (221,379) (46,109) 126,721 8,445 (132,322) Borrower Loans sold to third parties (3,412) (1,564,904) — — (1,568,316) Other changes 331 921 538 (351) 1,439 Change in fair value (35,955) (3,412) 17,171 5,937 (16,259) Balance at September 30, 2019 $ 540,969 $ 231,644 $ (247,725) $ (37,564) $ 487,324 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held For Sale Notes Certificates Issued by Securitization Trust Total Balance at July 1, 2020 $ 457,487 $ 216,243 $ (209,987) $ (31,571) $ 432,172 Purchase of Borrower Loans/Issuance of Notes 31,742 327,407 (32,260) — 326,889 Principal repayments (79,658) (29,809) 36,943 6,733 (65,791) Borrower Loans sold to third parties (1,383) (262,502) — — (263,885) Other changes (926) 164 233 49 (480) Change in fair value 7,615 940 (1,860) (1,992) 4,703 Balance at September 30, 2020 $ 414,877 $ 252,443 $ (206,931) $ (26,781) $ 433,608 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Certificates Issued by Securitization Trust Total Balance at July 1, 2019 $ 606,799 $ 114,962 $ (253,425) $ (44,090) $ 424,246 Purchase of Borrower Loans/Issuance of Notes 41,460 647,896 (41,439) — 647,917 Principal repayments (87,348) (19,580) 40,993 4,173 (61,762) Borrower Loans sold to third parties (1,526) (511,596) — — (513,122) Other changes 240 832 (65) 252 1,259 Change in fair value (18,656) (870) 6,211 2,101 (11,214) Balance at September 30, 2019 $ 540,969 $ 231,644 $ (247,725) $ (37,564) $ 487,324
Schedule of Servicing Assets and Liabilities Measured at Fair Value	The following tables present additional information about Level 3 Servicing Assets measured at fair value on a recurring basis for the three and nine month periods ending September 30, 2020 and 2019 (in thousands): Servicing Assets Fair Value at January 1, 2020 $ 12,602 Additions 3,945 Less: Changes in fair value (7,241) Fair Value at September 30, 2020 $ 9,306 Servicing Assets Fair Value at January 1, 2019 $ 14,687 Additions 9,237 Derecognition (1,049) Less: Changes in fair value (9,939) Fair Value at September 30, 2019 $ 12,936 Servicing Assets Fair Value at July 1, 2020 $ 10,073 Additions 1,242 Less: Changes in fair value (2,009) Fair Value at September 30, 2020 $ 9,306 Servicing Assets Fair Value at July 1, 2019 $ 13,387 Additions 2,859 Less: Changes in fair value (3,310) Fair Value at September 30, 2019 $ 12,936 The following tables present additional information about the Level 3 Convertible Preferred Stock Warrant Liability measured at fair value on a recurring basis for the three and nine month periods ending September 30, 2020 and 2019 (in thousands): Convertible Preferred Stock Balance as of January 1, 2020 $ 149,996 Change in fair value (63,624) Balance as of September 30, 2020 $ 86,372 Convertible Preferred Stock Balance as of January 1, 2019 $ 143,679 Issuance of Stock Warrants 17,553 Change in fair value (8,890) Balance as of September 30, 2019 $ 152,342 Convertible Preferred Stock Balance as of July 1, 2020 $ 74,998 Change in fair value 11,374 Balance as of September 30, 2020 $ 86,372 Convertible Preferred Stock Balance as of July 1, 2019 $ 166,559 Change in fair value (14,217) Balance as of September 30, 2019 $ 152,342
Fair Value, Liabilities Measured on Recurring Basis	The following tables present additional information about the Level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis for the three and nine month periods ending September 30, 2020 and 2019 (in thousands): Loan Trailing Fee Liability Balance at January 1, 2020 $ 2,997 Issuances 938 Cash Payment of Loan Trailing Fee (1,867) Change in Fair Value 194 Balance at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Balance at January 1, 2019 $ 3,118 Issuances 2,063 Cash Payment of Loan Trailing Fee (1,744) Change in Fair Value (156) Balance at September 30, 2019 $ 3,281 Loan Trailing Fee Liability Balance at July 1, 2020 $ 2,403 Issuances 313 Cash Payment of Loan Trailing Fee (596) Change in Fair Value 142 Balance at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Balance at July 1, 2019 $ 3,249 Issuances 766 Cash Payment of Loan Trailing Fee (446) Change in Fair Value (288) Balance at September 30, 2019 $ 3,281
Fair Value Assumptions for Loans Held for Sale, Borrower Loans and Notes	Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Borrower Loans and Loans Held for Sale are presented in the following table (in thousands, except percentages). Borrower Loans and Loans Held for Sale September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 667,320 $ 776,045 Weighted-average discount rate 9.57 % 7.00 % Weighted-average default rate 12.50 % 12.63 % Fair value resulting from: 100 basis point increase in discount rate $ 661,563 $ 768,924 200 basis point increase in discount rate $ 655,937 $ 761,971 Fair value resulting from: 100 basis point decrease in discount rate $ 673,214 $ 783,344 200 basis point decrease in discount rate $ 679,249 $ 790,823 Fair value resulting from: 10 percent increase in default rate $ 660,416 $ 765,894 20 percent increase in default rate $ 653,543 $ 756,007 Fair value resulting from: 10 percent decrease in default rate $ 674,253 $ 786,541 20 percent decrease in default rate $ 681,220 $ 797,065 Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Notes are presented in the following table (in thousands, except percentages). Notes September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 206,931 $ 244,171 Weighted-average discount rate 10.50 % 6.43 % Weighted-average default rate 12.90 % 13.68 % Fair value resulting from: 100 basis point increase in discount rate $ 205,143 $ 241,927 200 basis point increase in discount rate $ 203,396 $ 239,737 Fair value resulting from: 100 basis point decrease in discount rate $ 208,761 $ 246,471 200 basis point decrease in discount rate $ 210,635 $ 248,828 Fair value resulting from: 10 percent increase in default rate $ 204,777 $ 240,958 20 percent increase in default rate $ 202,634 $ 237,831 Fair value resulting from: 10 percent decrease in default rate $ 209,093 $ 247,489 20 percent decrease in default rate $ 211,266 $ 250,817 Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Certificates Issued by Securitization Trust are presented in the following table (in thousands, except percentages). Certificates Issued by Securitization Trust September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 26,781 $ 52,168 Weighted-average discount rate 12.78 % 9.59 % Weighted-average default rate 12.10 % 10.12 % Weighted-average prepayment rate 20.03 % 21.41 % Fair value resulting from: 100 basis point increase in discount rate $ 26,560 $ 51,813 200 basis point increase in discount rate $ 26,345 $ 51,466 Fair value resulting from: 100 basis point decrease in discount rate $ 27,007 $ 52,533 200 basis point decrease in discount rate $ 27,240 $ 52,909 Fair value resulting from: 10 percent increase in default rate $ 25,330 $ 48,986 20 percent increase in default rate $ 23,878 $ 45,926 Fair value resulting from: 10 percent decrease in default rate $ 28,222 $ 55,369 20 percent decrease in default rate $ 29,665 $ 58,613 Fair value resulting from: 10 percent increase in prepayment rate $ 26,815 $ 52,085 20 percent increase in prepayment rate $ 26,852 $ 52,008 Fair value resulting from: 10 percent decrease in prepayment rate $ 26,763 $ 52,253 20 percent decrease in prepayment rate $ 26,749 $ 52,340
Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities	Key economic assumptions and the sensitivity of the fair value to immediate changes in those assumptions at September 30, 2020 and December 31, 2019 for Servicing Assets is presented in the following table (in thousands, except percentages). Servicing Assets September 30, 2020 December 31, 2019 Fair value, using the following assumptions $ 9,306 $ 12,602 Weighted-average market servicing rate 0.634 % 0.625 % Weighted-average prepayment rate 20.13 % 20.99 % Weighted-average default rate 13.13 % 12.67 % Fair value resulting from: Market servicing rate increase of 0.025% $ 8,746 $ 11,825 Market servicing rate decrease of 0.025% $ 9,865 $ 13,387 Fair value resulting from: Applying a 1.1 multiplier to prepayment rate $ 9,124 $ 12,348 Applying a 0.9 multiplier to prepayment rate $ 9,489 $ 12,868 Fair value resulting from: Applying a 1.1 multiplier to default rate $ 9,176 $ 12,377 Applying a 0.9 multiplier to default rate $ 9,435 $ 12,840
Financial Instruments, Assets And Liabilities Not Recorded At Fair Value	The following table presents the fair value hierarchy for assets, and liabilities not recorded at fair value (in thousands): September 30, 2020 Carrying Amount Level 1 Inputs Level 2 Inputs Level 3 Inputs Balance at Fair Value Assets: Cash and Cash Equivalents $ 45,898 $ 45,898 $ — $ — $ 45,898 Restricted Cash 135,826 — 135,826 — 135,826 Accounts Receivable 533 — 533 — 533 Total Assets $ 182,257 $ 45,898 $ 136,359 $ — $ 182,257 Liabilities: Accounts Payable and Accrued Liabilities $ 14,600 $ — $ 14,600 $ — $ 14,600 Payable to Investors 95,887 — 95,887 — 95,887 Notes Issued by Securitization Trust 192,829 — 193,713 — 193,713 Warehouse Lines 226,784 — 226,267 — 226,267 Total Liabilities $ 530,100 $ — $ 530,467 $ — $ 530,467 December 31, 2019 Carrying Amount Level 1 Inputs Level 2 Inputs Level 3 Inputs Balance at Fair Value Assets: Cash and Cash Equivalents $ 64,635 $ 64,635 $ — $ — $ 64,635 Restricted Cash 155,773 — 155,773 — 155,773 Accounts Receivable 1,695 — 1,695 — 1,695 Total Assets $ 222,103 $ 64,635 $ 157,468 $ — $ 222,103 Liabilities: Accounts Payable and Accrued Liabilities $ 19,937 $ — $ 19,937 $ — $ 19,937 Payable to Investors 101,092 — 101,092 — 101,092 Notes Issued by Securitization Trust 347,662 — 353,028 — 353,028 Warehouse Lines 131,583 — 131,090 — 131,090 Total Liabilities $ 600,274 $ — $ 605,147 $ — $ 605,147
Prosper Funding LLC
Entity Information [Line Items]
Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value	The following tables present the fair value hierarchy for assets and liabilities measured at fair value (in thousands): September 30, 2020 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 208,044 $ 208,044 Servicing Assets — — 11,265 11,265 Total Assets $ — $ — $ 219,309 $ 219,309 Liabilities: Notes $ — $ — $ 206,931 $ 206,931 Loan Trailing Fee Liability — — 2,262 2,262 Total Liabilities $ — $ — $ 209,193 $ 209,193 December 31, 2019 Level 1 Inputs Level 2 Inputs Level 3 Inputs Total Assets: Borrower Loans $ — $ — $ 245,137 $ 245,137 Servicing Assets — — 14,888 14,888 Total Assets $ — $ — $ 260,025 $ 260,025 Liabilities: Notes $ — $ — $ 244,171 $ 244,171 Loan Trailing Fee Liability — — 2,997 2,997 Total Liabilities $ — $ — $ 247,168 $ 247,168
Quantitative Information About Significant Unobservable Inputs	The following tables present quantitative information about the significant unobservable inputs used for Prosper Funding’s Level 3 fair value measurements at the dates presented: Range Borrower Loans and Notes September 30, 2020 December 31, 2019 Discount rate 7.2% - 17.0% 4.4% - 12.1% Default rate 2.6% - 16.85% 2.4% - 17.7% Range Servicing Assets September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1% Market servicing rate (1) (2) 0.625% - 0.818% 0.625 % (1) Servicing assets associated with loans enrolled in a relief program offered by the Company in response to the COVID-19 pandemic as of September 30, 2020 were measured using a market servicing rate assumption of 81.8 basis points. This rate was estimated using a multiplier consistent with observable market rates for other loan types, applied to the base market servicing rate assumption of 62.5 basis points. (2) Excludes collection fees that would be passed on to a hypothetical third-party servicer. As of September 30, 2020 and December 31, 2019, the market rate for collection fees and non-sufficient fund fees was assumed to be 7 b asis points and 6 basis points, respectively, for a total market servicing rate range of 69.5 - 88.8 basis points and a total market servicing rate o f 68.5 basis po ints, respectively. Range Loan Trailing Fee Liability September 30, 2020 December 31, 2019 Discount rate 15.0% - 25.0% 15.0% - 25.0% Default rate 1.9% - 18.5% 1.7% - 18.8% Prepayment rate 13.4% - 24.5% 16.5% - 28.1%
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present additional information about Level 3 Borrower Loans, Loans Held for Sale and Notes measured at fair value on a recurring basis for three months ended September 30, 2020 and 2019 (in thousands): Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at January 1, 2020 $ 245,137 $ — $ (244,171) $ 966 Originations 97,406 949,529 (97,303) 949,632 Principal repayments (112,034) — 114,051 2,017 Borrower Loans sold to third parties (2,111) (949,529) — (951,640) Other changes (23) — (25) (48) Change in fair value (20,331) — 20,517 186 Balance at September 30, 2020 $ 208,044 $ — $ (206,931) $ 1,113 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at January 1, 2019 $ 263,522 $ — $ (264,003) $ (481) Originations 127,522 1,809,133 (128,152) 1,808,503 Principal repayments (123,014) — 126,721 3,707 Borrower Loans sold to third parties (2,578) (1,809,133) — (1,811,711) Other changes (226) — 538 312 Change in fair value (17,508) — 17,171 (337) Balance at September 30, 2019 $ 247,718 $ — $ (247,725) $ (7) Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at July 1, 2020 $ 211,775 $ — $ (209,986) $ 1,789 Originations 31,742 327,407 (32,260) 326,889 Principal repayments (36,438) — 36,943 505 Borrower Loans sold to third parties (547) (327,407) — (327,954) Other changes (276) — 232 (44) Change in fair value 1,788 — (1,860) (72) Balance at September 30, 2020 $ 208,044 $ — $ (206,931) $ 1,113 Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Assets Liabilities Borrower Loans Loans Held for Sale Notes Total Balance at July 1, 2019 $ 254,070 $ — $ (253,425) $ 645 Originations 41,460 647,896 (41,439) 647,917 Principal repayments (40,600) — 40,993 393 Borrower Loans sold to third parties (855) (647,896) — (648,751) Other changes (26) — (65) (91) Change in fair value (6,331) — 6,211 (120) Balance at September 30, 2019 $ 247,718 $ — $ (247,725) $ (7)
Schedule of Servicing Assets and Liabilities Measured at Fair Value	The following tables present additional information about Level 3 Servicing Assets recorded at fair value (in thousands): Servicing Assets Fair Value at January 1, 2020 $ 14,888 Additions 5,034 Less: Changes in fair value (8,657) Fair Value at September 30, 2020 $ 11,265 Servicing Assets Fair Value at January 1, 2019 $ 15,550 Additions 10,232 Less: Changes in fair value (10,562) Fair Value at September 30, 2019 $ 15,220 Servicing Assets Fair Value at July 1, 2020 $ 12,063 Additions 1,632 Less: Changes in fair value (2,430) Fair Value at September 30, 2020 $ 11,265 Servicing Assets Fair Value at July 1, 2019 $ 15,461 Additions 3,436 Less: Changes in fair value (3,677) Fair Value at September 30, 2019 $ 15,220 Loan Trailing Fee Liability The fair value of the Loan Trailing Fee Liability represents the present value of the expected monthly Loan Trailing Fee payments, which takes into consideration certain assumptions related to expected prepayment rates and default rates using a discounted cash flow model. The assumptions used are the same as those used for the valuation of Servicing Assets, as described below. The following tables present additional information about Level 3 Loan Trailing Fee Liability measured at fair value on a recurring basis (in thousands): Loan Trailing Fee Liability Fair Value at January 1, 2020 $ 2,997 Issuances 938 Cash payment of Loan Trailing Fee (1,867) Change in fair value 194 Fair Value at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Fair Value at January 1, 2019 $ 3,118 Issuances 2,063 Cash payment of Loan Trailing Fee (1,744) Change in fair value (156) Fair Value at September 30, 2019 $ 3,281 Loan Trailing Fee Liability Balance at July 1, 2020 $ 2,403 Issuances 313 Cash payment of Loan Trailing Fee (596) Change in fair value 142 Fair Value at September 30, 2020 $ 2,262 Loan Trailing Fee Liability Balance at July 1, 2019 $ 3,249 Issuances 766 Cash payment of Loan Trailing Fee (446) Change in fair value (288) Fair Value at September 30, 2019 $ 3,281
Fair Value Assumptions for Loans Held for Sale, Borrower Loans and Notes	Key economic assumptions are used to compute the fair value of Borrower Loans. The sensitivity of the fair value to immediate changes in assumptions at September 30, 2020 and December 31, 2019 for Borrower Loans are presented in the following table (in thousands, except percentages). Borrower Loans September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 208,044 $ 245,137 Weighted-average discount rate 10.50 % 6.43 % Weighted-average default rate 12.90 % 13.68 % Fair value resulting from: 100 basis point increase in discount rate $ 206,249 $ 242,888 200 basis point increase in discount rate 204,495 240,691 Fair value resulting from: 100 basis point decrease in discount rate $ 209,881 $ 247,442 200 basis point decrease in discount rate 211,763 249,805 Fair value resulting from: 10 percent increase in default rate $ 205,891 $ 241,930 20 percent increase in default rate 203,749 238,807 Fair value resulting from: 10 percent decrease in default rate $ 210,205 $ 248,453 20 percent decrease in default rate 212,377 251,777 Key economic assumptions are used to compute the fair value of Notes. The sensitivity of the fair value to immediate changes in assumptions at September 30, 2020 and December 31, 2019 for Notes funded through the Note Channel are presented in the following table (in thousands, except percentages). Notes September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 206,931 $ 244,171 Weighted-average discount rate 10.50 % 6.43 % Weighted-average default rate 12.90 % 13.68 % Fair value resulting from: 100 basis point increase in discount rate $ 205,143 $ 241,927 200 basis point increase in discount rate 203,396 239,737 Fair value resulting from: 100 basis point decrease in discount rate $ 208,761 $ 246,471 200 basis point decrease in discount rate 210,635 248,828 Fair value resulting from: 10 percent increase in default rate $ 204,777 $ 240,958 20 percent increase in default rate 202,634 237,831 Fair value resulting from: 10 percent decrease in default rate $ 209,093 $ 247,489 20 percent decrease in default rate 211,266 250,817
Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities	Key economic assumptions are used to compute the fair value of Servicing Assets. The sensitivity of the current fair value to immediate changes in assumptions at September 30, 2020 and December 31, 2019 for Servicing Assets are presented in the following table (in thousands, except percentages). Servicing Assets September 30, 2020 December 31, 2019 Fair value, using the following assumptions: $ 11,265 $ 14,888 Weighted-average market servicing rate 0.634 % 0.625 % Weighted-average prepayment rate 20.13 % 20.99 % Weighted-average default rate 13.13 % 12.67 % Fair value resulting from: Market servicing rate increase of 0.025% $ 10,588 $ 13,966 Market servicing rate decrease of 0.025% 11,943 15,811 Fair value resulting from: Applying a 1.1 multiplier to prepayment rate $ 11,045 $ 14,583 Applying a 0.9 multiplier to prepayment rate 11,488 15,197 Fair value resulting from: Applying a 1.1 multiplier to default rate $ 11,109 $ 14,618 Applying a 0.9 multiplier to default rate 11,422 15,165

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Other Intangible Assets for the Period Presented	The following table presents the detail of other intangible assets subject to amortization as of the following date (dollars in thousands): September 30, 2020 Gross Carrying Value Accumulated Amortization Net Carrying Value Remaining Useful Life (In Years) Developed technology $ 3,060 $ (3,060) $ — — User base and customer relationships 5,050 (4,495) 555 4.6 Brand name 60 (60) — — Total Intangible Assets subject to amortization $ 8,170 $ (7,615) $ 555
Summary of Estimated Amortization of Purchased Intangible Assets	Estimated amortization of purchased intangible assets for future periods is as follows (in thousands): Year Ending December 31, 2020 (remainder thereof) $ 55 2021 172 2022 136 2023 107 2024 85 Total $ 555

Other Liabilities (Tables)

Other Liabilities (Tables)	9 Months Ended
	Sep. 30, 2020
Other Liabilities [Abstract]
Schedule of Other Liabilities	Other Liabilities consist of the following (in thousands): September 30, 2020 December 31, 2019 Operating lease liabilities $ 14,505 $ 17,507 PPP loan 8,484 — Loan trailing fee 2,262 2,997 Deferred income tax liability 507 405 Deferred revenue 90 241 Other 370 576 Total Other Liabilities $ 26,218 $ 21,726

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Basic and Diluted Net Income (Loss) per Share	Basic and diluted income (loss) per share was calculated as follows for the periods presented (in thousands, except share and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Numerator: Net (Loss) Income $ (2,025) $ 10,769 $ 36,746 $ (12,514) Plus: return on share purchase 2,381 — 2,381 — Less: net income allocated to participating securities (255) (7,994) (28,814) — Net income (loss) available to common stockholders $ 101 $ 2,775 $ 10,313 $ (12,514) Denominator: Weighted average shares used in computing net income (loss) per share - basic 68,485,173 70,606,805 68,465,046 70,532,641 Effect of dilutive securities: Stock options 14,902,171 1,939,105 50,778,284 — Convertible preferred stock warrants 213,264,845 213,264,845 213,264,845 — Weighted average shares used in computing diluted net income (loss) per share - diluted 296,652,189 285,810,755 332,508,175 70,532,641 Net income (loss) per share - basic $ — $ 0.04 $ 0.15 $ (0.18) Net income (loss) per share - diluted $ — $ 0.01 $ 0.03 $ (0.18)
Common Stock Equivalents Excluded from Computation of Diluted Net Income (Loss) per Share	The following common stock equivalents were excluded from the computation of diluted net income (loss) per share for the periods presented because including them would have been anti-dilutive: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 (shares) (shares) (shares) (shares) Excluded securities: Convertible preferred stock issued and outstanding, excluding shares held by consolidated VIE 181,761,442 214,637,925 200,261,761 214,637,925 Stock options issued and outstanding 58,390,141 73,211,425 22,127,694 73,029,965 Warrants issued and outstanding 1,080,349 1,080,349 1,080,349 1,080,349 Series E-1 convertible preferred stock warrants — 35,544,141 — 35,544,141 Series F convertible preferred stock warrants — 177,720,704 — 177,720,704 Total common stock equivalents excluded from diluted net income (loss) per common share computation 241,231,932 502,194,544 223,469,804 502,013,084

Convertible Preferred Stock, _2

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit (Tables)	9 Months Ended
	Sep. 30, 2020
Stockholders' Equity Note [Abstract]
Summary of Shares Authorized, Issued, Outstanding, Par Value and Liquidation Preference of Convertible Preferred Stock	The number of authorized, issued and outstanding shares, their par value and liquidation preference for each series of convertible preferred stock as of September 30, 2020 are disclosed in the table below (amounts in thousands except share and par value amounts): Convertible Preferred Stock Par Value Authorized Shares Outstanding and Issued Shares Liquidation Preference, Outstanding Shares Series A $ 0.01 68,558,220 66,428,185 * $ 19,160 Series A-1 $ 0.01 24,760,915 22,515,315 45,031 Series B $ 0.01 35,775,880 35,127,160 * 21,190 Series C $ 0.01 24,404,770 24,404,770 70,075 Series D $ 0.01 23,888,640 23,888,640 165,000 Series E-1 $ 0.01 35,544,141 — — Series E-2 $ 0.01 16,858,078 — — Series F $ 0.01 177,720,707 3 — Series G $ 0.01 37,249,497 37,249,497 50,000 Total 444,760,848 209,613,570 $ 370,456
Schedule of Assumptions Used	The Company determined the fair value of the outstanding Series E-1 Warrants utilizing the following assumptions as of the following dates: September 30, 2020 December 31, 2019 Volatility 66.0 % 46.0 % Risk-free interest rate 0.20 % 1.60 % Expected term (in years) 2.75 2.75 Dividend yield — % — % The Company determined the fair value of the outstanding Series F Warrants utilizing the following assumptions as of the following dates: September 30, 2020 December 31, 2019 Volatility 66.0 % 46.0 % Risk-free interest rate 0.20 % 1.60 % Expected term (in years) 2.75 2.75 Dividend yield — % — %
Schedule of Stockholders' Equity Note, Warrants or Rights	The combined activity of the Convertible Preferred Stock Warrant Liability for the nine months ended September 30, 2020 and 2019 are as follows (in thousands): Warrant Activity Balance at January 1, 2020 $ 149,996 Change in fair value (63,624) Balance at September 30, 2020 $ 86,372 Warrant Activity Balance at January 1, 2019 $ 143,679 Warrants vested 17,553 Change in fair value (8,890) Balance at September 30, 2019 $ 152,342

Share Based Incentive Plan an_2

Share Based Incentive Plan and Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Summarized Option Activity under Option Plan	Stock option activity under the 2005 Plan and 2015 Plan is summarized for the nine months ended September 30, 2020 below: Options Issued and Outstanding Weighted- Average Exercise Price Balance as of January 1, 2020 76,236,757 $ 0.31 Options issued 8,308,000 0.08 Options exercised (406,685) 0.02 Options forfeited (6,724,169) 0.34 Options expired (3,351,580) 0.13 Balance as of September 30, 2020 74,062,323 0.02 Options vested and expected to vest as of September 30, 2020 59,837,480 0.02 Options vested and exercisable at September 30, 2020 50,344,747 0.02
Fair Value of Stock Option Awards	The fair value of PMI’s stock option awards granted during the three and nine months ended September 30, 2020 and 2019 was estimated at the date of grant using the Black-Scholes model with the following average assumptions: Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Volatility of common stock 57.32 % 46.72 % 52.66 % 46.72 % Risk-free interest rate 0.37 % 1.57 % 0.51 % 2.24 % Expected life 6.0 years 6.0 years 6.0 years 5.9 years Dividend yield — % — % — % — %
Summarized Activities for RSU's	The following table summarizes the number of PMI’s outstanding RSUs and their weighted-average grant date fair value for the nine months ended September 30, 2020: Number of Shares Weighted-Average Grant Date Fair Value Unvested - January 1, 2020 4,803,141 $ 0.95 Forfeited (142,000) $ 2.18 Unvested - September 30, 2020 4,661,141 $ 0.91
Stock Based Compensation Included in Consolidated Statements of Operations	The following table presents the amount of stock-based compensation related to stock-based awards granted to employees recognized in Prosper’s condensed consolidated statements of operations for the periods presented (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Origination and servicing $ 53 $ 73 $ 124 $ 377 Sales and marketing 25 71 51 216 General and administrative 708 844 1,508 3,245 Total stock-based compensation $ 786 $ 988 $ 1,683 $ 3,838

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Summary of Operating Lease Right-of-Use Assets	The following table summarizes the operating lease right-of-use assets as of September 30, 2020, which are included in “Property and Equipment, Net” on the condensed consolidated balance sheets. September 30, 2020 Gross Carrying Value Accumulated Amortization Net Carrying Value ROU Assets - Office buildings $ 15,694 $ 5,796 $ 9,898 ROU Assets - Other 290 6 284 Total right-of-use assets subject to amortization $ 15,984 $ 5,802 $ 10,182
Schedule of Future Minimum Lease Payments	Future maturities of operating lease liabilities as of September 30, 2020 were as follows (in thousands). The present value of the future minimum lease payments represent our lease liabilities as of September 30, 2020 and are included in " Other Liabilities Minimum Lease Payments Remainder of 2020 $ 1,338 2021 5,279 2022 5,121 2023 1,562 2024 871 Thereafter 1,820 Total future minimum lease payments $ 15,991 Less imputed interest (1,486) Present value of future minimum lease payments $ 14,505
Summary of Other Information Related to Leases	Other information related to leases was as follows ($ in thousands): September 30, 2020 Cash paid for operating leases year-to-date $ 3,996 Right of use assets obtained in exchange for new operating lease obligations $ 290 Weighted average remaining lease term (in years) 3.55 years Weighted average discount rate 5.50 %

Related Parties (Tables)

Related Parties (Tables)	9 Months Ended
	Sep. 30, 2020
Entity Information [Line Items]
Aggregate Amount of Notes Purchased and the Income Earned	The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be affiliates and related parties of Prosper for the three and nine months ended September 30, 2020 and 2019, as well as the Notes and Borrower Loans outstanding as of September 30, 2020 and December 31, 2019 are summarized below (in thousands): Aggregate Amount of Interest Earned on Related Party 2020 2019 2020 2019 Executive officers and management $ 7 $ 6 $ 1 $ 1 Directors (excluding executive officers and management) 41 101 14 13 Total $ 48 $ 107 $ 15 $ 14 Aggregate Amount of Interest Earned on Related Party 2020 2019 2020 2019 Executive officers and management $ 19 $ 17 $ 4 $ 4 Directors (excluding executive officers and management) 272 309 43 37 Total $ 291 $ 326 $ 47 $ 41 Notes Balance as of Related Party September 30, 2020 December 31, 2019 Executive officers and management $ 37 $ 35 Directors (excluding executive officers and management) 549 682 $ 586 $ 717
Prosper Funding LLC
Entity Information [Line Items]
Aggregate Amount of Notes Purchased and the Income Earned	The aggregate amount of the Notes and Borrower Loans purchased and the income earned by parties deemed to be related parties of Prosper Funding for the three and nine months ended September 30, 2020 and 2019 are summarized below (in thousands): Aggregate Purchases Interest Earned Three Months Ended September 30, Three Months Ended September 30, Related Party 2020 2019 2020 2019 Executive officers and management $ 7 $ 6 $ 1 $ 1 Directors (excluding executive officers and management) — — — — Total $ 7 $ 6 $ 1 $ 1 Aggregate Purchases Interest Earned Nine Months Ended September 30, Nine Months Ended September 30, Related Party 2020 2019 2020 2019 Executive officers and management $ 19 $ 17 $ 4 $ 4 Directors (excluding executive officers and management) — — — — Total $ 19 $ 17 $ 4 $ 4 The balance of Notes held by officers and directors who are not executive officers are as follows (in thousands): Notes Balance as of Related Party September 30, 2020 December 31, 2019 Executive officers and management $ 37 $ 35 Directors (excluding executive officers and management) — — $ 37 $ 35

Property and Equipment, Net (De

Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment	$ 76,174	$ 71,139
Less: Accumulated depreciation and amortization	(46,591)	(39,843)
Total Property and Equipment, Net	29,583	31,296
Prosper Funding LLC
Property, Plant and Equipment [Line Items]
Less: Accumulated depreciation and amortization	(19,086)	(17,381)
Total Property and Equipment, Net	7,351	7,549
Operating lease right-of-use assets
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets	15,984	16,213
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment	13,558	13,420
Internal-use software and website development costs
Property, Plant and Equipment [Line Items]
Property and equipment	32,446	28,904
Internal-use software and website development costs | Prosper Funding LLC
Property, Plant and Equipment [Line Items]
Property and equipment	26,437	24,930
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Property and equipment	2,999	2,999
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	7,167	7,158
Assets not yet placed in service
Property, Plant and Equipment [Line Items]
Property and equipment	$ 4,020	$ 2,445

Property and Equipment, Net - A

Property and Equipment, Net - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Depreciation and Amortization			$ 6,196	$ 5,649
Prosper Funding LLC
Property, Plant and Equipment [Line Items]
Depreciation and Amortization	$ 1,100	$ 1,100	3,132	3,279
Property Plant And Equipment
Property, Plant and Equipment [Line Items]
Depreciation and Amortization	2,100	1,800	6,000	5,400
Internal-use software and website development costs
Property, Plant and Equipment [Line Items]
Capitalized internal-use software and website development costs	$ 1,800	$ 2,600	$ 6,500	$ 6,900

Borrower Loans, Loans Held fo_3

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value - Aggregate Principal Balances Outstanding and Fair Values of Borrower Loans, Notes and Loans Held for Sale (Details) - USD ($) $ in Thousands		9 Months Ended	12 Months Ended
		Sep. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, at Fair Value	[1]	$ 414,877	$ 634,019
Loans Held for Sale	[1]	252,443	142,026
Notes, at Fair Value		(206,931)	(244,171)
Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Borrower Loans, at Fair Value		208,044	245,137
Notes, at Fair Value		(206,931)	(244,171)
Senior Notes
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding, Notes		(219,730)	(250,281)
Fair value adjustments, Notes		12,799	6,110
Notes, at Fair Value		(206,931)	(244,171)
Senior Notes | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding, Notes		(219,730)	(250,281)
Fair value adjustments, Notes		12,799	6,110
Notes, at Fair Value		(206,931)	(244,171)
Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding		440,460	647,209
Fair value adjustments		(25,583)	(13,190)
Borrower Loans, at Fair Value		414,877	634,019
Borrower Loans | Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Aggregate principal balance outstanding		218,064	248,702
Fair value adjustments		(10,020)	(3,565)
Borrower Loans, at Fair Value		208,044	245,137
Loans Held for Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fair value adjustments		(7,962)	(1,235)
Aggregate principal balance outstanding, Loans Held for Sale		260,405	143,261
Loans Held for Sale		$ 252,443	$ 142,026
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.

Borrower Loans, Loans Held fo_4

Borrower Loans, Loans Held for Sale, and Notes Held at Fair Value - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Non accrual status past due date			120 days
Interest income	$ 11,174	$ 11,774	$ 33,510	$ 24,980
Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fixed interest rate, minimum			5.31%		5.31%
Fixed interest rate, maximum			31.82%		31.92%
Minimum number of days for which loans originated were delinquent			90 days		90 days
Aggregate principal amount of loans originated that are 90 days or more delinquent	3,500		$ 3,500		$ 6,500
Fair value of loans originated that are 90 days or more delinquent	300		300		1,900
Loans in non-accrual status	300		$ 300		$ 700
Loans Held for Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fixed interest rate, minimum			5.31%		5.31%
Fixed interest rate, maximum			31.82%		31.82%
Minimum number of days for which loans originated were delinquent					90 days
Aggregate principal amount of loans originated that are 90 days or more delinquent	800		$ 800		$ 700
Fair value of loans originated that are 90 days or more delinquent	100		100		200
Loans in non-accrual status	100		100		$ 100
Change in fair value			(12,900)	(3,400)
Interest income			19,200	13,100
Prosper Funding LLC
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Interest income	560	$ 657	$ 1,763	$ 2,007
Prosper Funding LLC | Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Fixed interest rate, minimum			5.31%		5.31%
Fixed interest rate, maximum			31.82%		31.92%
Minimum number of days for which loans originated were delinquent			90 days		90 days
Aggregate principal amount of loans originated that are 90 days or more delinquent	1,300		$ 1,300		$ 2,600
Fair value of loans originated that are 90 days or more delinquent	100		$ 100		800
Non accrual status past due date			120 days
Loans in non-accrual status	$ 100		$ 100		$ 300
Minimum | Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months			36 months		36 months
Minimum | Loans Held for Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months			36 months		36 months
Minimum | Prosper Funding LLC | Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months			36 months		36 months
Maximum | Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months			60 months		60 months
Maximum | Loans Held for Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months			60 months		60 months
Maximum | Prosper Funding LLC | Borrower Loans
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Maturity, in months			60 months		60 months

Loan Servicing Assets (Details)

Loan Servicing Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Servicing Assets And Liabilities Fair Value [Line Items]
Gain (loss) on sale of borrower loans	$ 786	$ 2,577	$ 3,147	$ 8,834
Loss from fair value of warrants vested on sale of borrower loans				17,600
Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Gain (loss) on sale of borrower loans	1,247	3,155	4,429	(7,725)
Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Outstanding principle	2,400,000		$ 2,400,000		$ 3,100,000
Fixed interest rate, minimum			5.31%		5.31%
Fixed interest rate, maximum			31.92%		31.92%
Contractually specified servicing fees, late charges and ancillary fees	6,700	9,300	$ 23,200	27,800
Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Outstanding principle	2,900,000		$ 2,900,000		$ 3,700,000
Fixed interest rate, minimum			5.31%		5.31%
Fixed interest rate, maximum			31.92%		31.92%
Contractually specified servicing fees, late charges and ancillary fees	$ 10,300	$ (10,700)	$ 33,300	$ 31,000
Minimum | Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			36 months		36 months
Minimum | Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			36 months		36 months
Maximum | Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			60 months		60 months
Maximum | Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Maturity, in months			60 months		60 months

Securitizations (Details)

Securitizations (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust	[1]	$ 192,829	$ 347,662
Borrower Loans, at Fair Value	[1]	414,877	634,019
Risk retention interest and residual certificates held by third party investors at fair value	[1]	26,781	52,168
Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust	[2]	192,829	347,662
Borrower Loans, at Fair Value	[2]	206,833	388,882
Risk retention interest and residual certificates held by third party investors at fair value	[2]	$ 26,781	52,168
PMIT 2019 Securitization Trusts | Primary Beneficiary
Variable Interest Entity [Line Items]
Securitization amount			$ 573,000
PMIT 2019-1 | Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership percentage		65.50%
Debt issuance costs		$ 2,300
Unamortized debt issuance costs		45,500
Borrower Loans, at Fair Value		47,600
Risk retention interest and residual certificates held by third party investors at fair value		4,500
2019-1, Class A Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust		$ 127,300
Interest rate		3.54%
2019-1, Class B Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust		$ 25,000
Interest rate		4.03%
2019-1, Class C Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust		$ 19,300
Interest rate		5.27%
PMIT 2019-2 | Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership percentage		16.40%
Debt issuance costs		$ 1,900
Unamortized debt issuance costs		69,600
Borrower Loans, at Fair Value		75,100
Risk retention interest and residual certificates held by third party investors at fair value		10,900
2019-2, Class A Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust		$ 110,100
Interest rate		3.20%
2019-2, Class B Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust		$ 31,400
Interest rate		3.69%
2019-2, Class C Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Notes Issued by Securitization Trust		$ 32,700
Interest rate		5.05%
PMIT 2019-4 | Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership percentage		19.60%
Debt issuance costs		$ 1,200
Unamortized debt issuance costs		77,700
Borrower Loans, at Fair Value		84,100
Risk retention interest and residual certificates held by third party investors at fair value		11,400
2019-4, Class A Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Securitization amount		$ 102,600
Interest rate		2.48%
2019-4, Class B Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Securitization amount		$ 19,500
Interest rate		3.20%
2019-4, Class C Notes | Primary Beneficiary
Variable Interest Entity [Line Items]
Securitization amount		$ 16,800
Interest rate		4.95%
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.
[2]	The following table presents the assets and liabilities of consolidated variable interest entities (VIEs), which are included in the condensed consolidated balance sheets above. The assets in the table below may only be used to settle obligations of consolidated VIEs and are in excess of those obligations. Additionally, the assets and liabilities in the table below include third-party assets and liabilities of consolidated VIEs only and exclude intercompany balances that eliminate in consolidation. See Note 6, Securitizations, and Note 10, Debt, to our Notes to Condensed Consolidated Financial Statements for add itional information.

Fair Value of Assets and Liab_3

Fair Value of Assets and Liabilities - Fair Value Hierarchy for Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Assets:
Borrower Loans	[1]	$ 414,877	$ 634,019
Loans Held for Sale	[1]	252,443	142,026
Servicing Assets		9,306	12,602
Total Assets		676,626	788,647
Liabilities:
Notes		206,931	244,171
Certificates Issued by Securitization Trust, at Fair Value	[1]	26,781	52,168
Convertible Preferred Stock Warrant Liability		86,372	149,996
Loan Trailing Fee Liability		2,262	2,997
Total Liabilities		322,346	449,332
Prosper Funding LLC
Assets:
Borrower Loans		208,044	245,137
Servicing Assets		11,265	14,888
Total Assets		219,309	260,025
Liabilities:
Notes		206,931	244,171
Loan Trailing Fee Liability		2,262	2,997
Total Liabilities		209,193	247,168
Level 1 Inputs
Assets:
Borrower Loans		0	0
Loans Held for Sale		0	0
Servicing Assets		0	0
Total Assets		0	0
Liabilities:
Notes		0	0
Certificates Issued by Securitization Trust, at Fair Value		0	0
Convertible Preferred Stock Warrant Liability		0	0
Loan Trailing Fee Liability		0	0
Total Liabilities		0	0
Level 1 Inputs | Prosper Funding LLC
Assets:
Borrower Loans		0	0
Servicing Assets		0	0
Total Assets		0	0
Liabilities:
Notes		0	0
Loan Trailing Fee Liability		0	0
Total Liabilities		0	0
Level 2 Inputs
Assets:
Borrower Loans		0	0
Loans Held for Sale		0	0
Servicing Assets		0	0
Total Assets		0	0
Liabilities:
Notes		0	0
Certificates Issued by Securitization Trust, at Fair Value		0	0
Convertible Preferred Stock Warrant Liability		0	0
Loan Trailing Fee Liability		0	0
Total Liabilities		0	0
Level 2 Inputs | Prosper Funding LLC
Assets:
Borrower Loans		0	0
Servicing Assets		0	0
Total Assets		0	0
Liabilities:
Notes		0	0
Loan Trailing Fee Liability		0	0
Total Liabilities		0	0
Level 3 Inputs
Assets:
Borrower Loans		414,877	634,019
Loans Held for Sale		252,443	142,026
Servicing Assets		9,306	12,602
Total Assets		676,626	788,647
Liabilities:
Notes		206,931	244,171
Certificates Issued by Securitization Trust, at Fair Value		26,781	52,168
Convertible Preferred Stock Warrant Liability		86,372	149,996
Loan Trailing Fee Liability		2,262	2,997
Total Liabilities		322,346	449,332
Level 3 Inputs | Prosper Funding LLC
Assets:
Borrower Loans		208,044	245,137
Servicing Assets		11,265	14,888
Total Assets		219,309	260,025
Liabilities:
Notes		206,931	244,171
Loan Trailing Fee Liability		2,262	2,997
Total Liabilities		$ 209,193	$ 247,168
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.

Fair Value of Assets and Liab_4

Fair Value of Assets and Liabilities - Significant Unobservable Inputs - Borrower Loans, Loans Held For Sale and Notes (Details)	Sep. 30, 2020	Dec. 31, 2019
Discount rate
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.1278	0.0959
Discount rate | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.055	0.044
Discount rate | Minimum | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.072	0.044
Discount rate | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.170	0.122
Discount rate | Maximum | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.170	0.121
Default rate
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.1210	0.1012
Default rate | Minimum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.023	0.021
Default rate | Minimum | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.026	0.024
Default rate | Maximum
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.181	0.186
Default rate | Maximum | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value measurement inputs	0.1685	0.177

Fair Value of Assets and Liab_5

Fair Value of Assets and Liabilities - Significant Unobservable Inputs - Certificates Issued by Securitization Trust (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	5.10%	4.00%
Default rate	3.30%	2.00%
Prepayment rate	8.70%	14.50%
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Discount rate	18.50%	15.00%
Default rate	16.30%	17.00%
Prepayment rate	35.10%	33.00%

Fair Value of Assets and Liab_6

Fair Value of Assets and Liabilities - Significant Unobservable Inputs - Servicing Rights (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Servicing Rights at Fair Value [Line Items]
Market servicing rate		0.625%
Collection fee market rate	0.07%	0.06%
Weighted-average market servicing rate		0.685%
Prosper Funding LLC
Servicing Rights at Fair Value [Line Items]
Market servicing rate		0.625%
Collection fee market rate	0.07%	0.06%
Weighted-average market servicing rate		0.685%
Minimum
Servicing Rights at Fair Value [Line Items]
Discount rate	15.00%	15.00%
Default rate	1.90%	1.70%
Prepayment rate	13.40%	16.50%
Market servicing rate	0.625%
Weighted-average market servicing rate	0.695%
Minimum | Prosper Funding LLC
Servicing Rights at Fair Value [Line Items]
Discount rate	15.00%	15.00%
Default rate	1.90%	1.70%
Prepayment rate	13.40%	16.50%
Market servicing rate	0.625%
Weighted-average market servicing rate	0.695%
Maximum
Servicing Rights at Fair Value [Line Items]
Discount rate	25.00%	25.00%
Default rate	18.50%	18.80%
Prepayment rate	24.50%	28.10%
Market servicing rate	0.818%
Weighted-average market servicing rate	0.888%
Maximum | Prosper Funding LLC
Servicing Rights at Fair Value [Line Items]
Discount rate	25.00%	25.00%
Default rate	18.50%	18.80%
Prepayment rate	24.50%	28.10%
Market servicing rate	0.818%
Weighted-average market servicing rate		0.888%

Fair Value of Assets and Liab_7

Fair Value of Assets and Liabilities - Significant Unobservable Inputs - Loan Trailing Fee Liability (Details)	Sep. 30, 2020	Dec. 31, 2019
Discount rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.1278	0.0959
Discount rate | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.055	0.044
Discount rate | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.170	0.122
Discount rate | Prosper Funding LLC | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.072	0.044
Discount rate | Prosper Funding LLC | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.170	0.121
Discount rate | Obligations | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.150	0.150
Discount rate | Obligations | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.250	0.250
Discount rate | Obligations | Prosper Funding LLC | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.150	0.150
Discount rate | Obligations | Prosper Funding LLC | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.250	0.250
Default rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.1210	0.1012
Default rate | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.023	0.021
Default rate | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.181	0.186
Default rate | Prosper Funding LLC | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.026	0.024
Default rate | Prosper Funding LLC | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.1685	0.177
Default rate | Obligations | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.019	0.017
Default rate | Obligations | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.185	0.188
Default rate | Obligations | Prosper Funding LLC | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.019	0.017
Default rate | Obligations | Prosper Funding LLC | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.185	0.188
Prepayment rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.2003	0.2141
Prepayment rate | Obligations | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.134	0.165
Prepayment rate | Obligations | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.245	0.281
Prepayment rate | Obligations | Prosper Funding LLC | Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.134	0.165
Prepayment rate | Obligations | Prosper Funding LLC | Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value measurement inputs	0.245	0.281

Fair Value of Assets and Liab_8

Fair Value of Assets and Liabilities - Changes in Level 3 Fair Value Assets and Liabilities on a Recurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Loans Held for Sale
Assets
Change in fair value			$ (12,900)	$ (3,400)
Recurring
Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Asset And Liability [Roll Forward]
Beginning balance, Total	$ 432,172	$ 424,246	479,706	183,307
Purchase of Borrower Loans/Issuance of Notes	326,889	647,917	949,632	2,019,475
Transfers in (Transfers out)				0
Principal repayments	(65,791)	(61,762)	(201,437)	(132,322)
Borrower Loans sold to third parties	(263,885)	(513,122)	(759,921)	(1,568,316)
Other changes	(480)	1,259	225	1,439
Change in fair value	4,703	(11,214)	(34,597)	(16,259)
Ending balance, Total	433,608	487,324	433,608	487,324
Recurring | Prosper Funding LLC
Fair Value Measurement With Unobservable Inputs Reconciliations Recurring Basis Asset And Liability [Roll Forward]
Beginning balance, Total	1,789	645	966	(481)
Originations	326,889	647,917	949,632	1,808,503
Principal repayments	505	393	2,017	3,707
Borrower Loans sold to third parties	(327,954)	(648,751)	(951,640)	(1,811,711)
Other changes	(44)	(91)	(48)	312
Change in fair value	(72)	(120)	186	(337)
Ending balance, Total	1,113	(7)	1,113	(7)
Recurring | Notes
Liabilities
Beginning balance, Liabilities	(209,987)	(253,425)	(244,171)	(264,003)
Purchase of Borrower Loans/Issuance of Notes	(32,260)	(41,439)	(97,303)	(128,152)
Transfers in (Transfers out)				0
Principal repayments	36,943	40,993	114,050	126,721
Borrower Loans sold to third parties	0	0	0	0
Other changes	233	(65)	(24)	538
Change in fair value	(1,860)	6,211	20,517	17,171
Ending balance, Liabilities	(206,931)	(247,725)	(206,931)	(247,725)
Recurring | Notes | Prosper Funding LLC
Liabilities
Beginning balance, Liabilities	(209,986)	(253,425)	(244,171)	(264,003)
Originations	(32,260)	(41,439)	(97,303)	(128,152)
Principal repayments	36,943	40,993	114,051	126,721
Borrower Loans sold to third parties	0	0	0	0
Other changes	232	(65)	(25)	538
Change in fair value	(1,860)	6,211	20,517	17,171
Ending balance, Liabilities	(206,931)	(247,725)	(206,931)	(247,725)
Recurring | Certificates Issued by Securitization Trust
Liabilities
Beginning balance, Liabilities	(31,571)	(44,090)	(52,168)	0
Purchase of Borrower Loans/Issuance of Notes	0	0	0	(51,595)
Transfers in (Transfers out)				0
Principal repayments	6,733	4,173	16,608	8,445
Borrower Loans sold to third parties	0	0	0	0
Other changes	49	252	390	(351)
Change in fair value	(1,992)	2,101	8,389	5,937
Ending balance, Liabilities	(26,781)	(37,564)	(26,781)	(37,564)
Recurring | Borrower Loans
Assets
Beginning balance, Assets	457,487	606,799	634,019	263,522
Purchase of Borrower Loans/Issuance of Notes	31,742	41,460	97,406	390,089
Transfers in (Transfers out)				147,773
Principal repayments	(79,658)	(87,348)	(259,210)	(221,379)
Borrower Loans sold to third parties	(1,383)	(1,526)	(5,637)	(3,412)
Other changes	(926)	240	(1,084)	331
Change in fair value	7,615	(18,656)	(50,617)	(35,955)
Ending balance, Assets	414,877	540,969	414,877	540,969
Recurring | Borrower Loans | Prosper Funding LLC
Assets
Beginning balance, Assets	211,775	254,070	245,137	263,522
Originations	31,742	41,460	97,406	127,522
Principal repayments	(36,438)	(40,600)	(112,034)	(123,014)
Borrower Loans sold to third parties	(547)	(855)	(2,111)	(2,578)
Other changes	(276)	(26)	(23)	(226)
Change in fair value	1,788	(6,331)	(20,331)	(17,508)
Ending balance, Assets	208,044	247,718	208,044	247,718
Recurring | Loans Held for Sale
Assets
Beginning balance, Assets	216,243	114,962	142,026	183,788
Purchase of Borrower Loans/Issuance of Notes	327,407	647,896	949,529	1,809,133
Transfers in (Transfers out)				(147,773)
Principal repayments	(29,809)	(19,580)	(72,885)	(46,109)
Borrower Loans sold to third parties	(262,502)	(511,596)	(754,284)	(1,564,904)
Other changes	164	832	943	921
Change in fair value	940	(870)	(12,886)	(3,412)
Ending balance, Assets	252,443	231,644	252,443	231,644
Recurring | Loans Held for Sale | Prosper Funding LLC
Assets
Beginning balance, Assets	0	0	0	0
Originations	327,407	647,896	949,529	1,809,133
Principal repayments	0	0	0	0
Borrower Loans sold to third parties	(327,407)	(647,896)	(949,529)	(1,809,133)
Other changes	0	0	0	0
Change in fair value	0	0	0	0
Ending balance, Assets	$ 0	$ 0	$ 0	$ 0

Fair Value of Assets and Liab_9

Fair Value of Assets and Liabilities - Summary of Additional Information for Level 3 Fair Value Balances (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Servicing Assets
Beginning balance			$ 12,602
Ending balance	$ 9,306		9,306
Prosper Funding LLC
Servicing Assets
Beginning balance			14,888
Ending balance	11,265		11,265
Servicing Assets
Servicing Assets
Beginning balance			12,602
Ending balance	9,306		9,306
Servicing Assets | Prosper Funding LLC
Servicing Assets
Beginning balance			14,888
Ending balance	11,265		11,265
Level 3 Inputs
Servicing Assets
Beginning balance			12,602
Ending balance	9,306		9,306
Level 3 Inputs | Prosper Funding LLC
Servicing Assets
Beginning balance			14,888
Ending balance	11,265		11,265
Level 3 Inputs | Servicing Assets
Servicing Assets
Beginning balance	10,073	$ 13,387	12,602	$ 14,687
Additions	1,242	2,859	3,945	9,237
Derecognition				(1,049)
Less: Changes in fair value	(2,009)	(3,310)	(7,241)	(9,939)
Ending balance	9,306	12,936	9,306	12,936
Level 3 Inputs | Servicing Assets | Prosper Funding LLC
Servicing Assets
Beginning balance	12,063	15,461	14,888	15,550
Additions	1,632	3,436	5,034	10,232
Less: Changes in fair value	(2,430)	(3,677)	(8,657)	(10,562)
Ending balance	11,265	15,220	11,265	15,220
Level 3 Inputs | Mandatorily Redeemable Preferred Stock
Liabilities
Beginning balance	74,998	166,559	149,996	143,679
Issuances				17,553
Change in fair value	11,374	(14,217)	(63,624)	(8,890)
Ending balance	86,372	152,342	86,372	152,342
Level 3 Inputs | Loan Trailing Fee Liability
Liabilities
Beginning balance	2,403	3,249	2,997	3,118
Issuances	313	766	938	2,063
Principal repayments	(596)	(446)	(1,867)	(1,744)
Change in fair value	142	(288)	194	(156)
Ending balance	2,262	3,281	2,262	3,281
Level 3 Inputs | Loan Trailing Fee Liability | Prosper Funding LLC
Liabilities
Beginning balance	2,403	3,249	2,997	3,118
Issuances	313	766	938	2,063
Principal repayments	(596)	(446)	(1,867)	(1,744)
Change in fair value	142	(288)	194	(156)
Ending balance	$ 2,262	$ 3,281	$ 2,262	$ 3,281

Fair Value of Assets and Lia_10

Fair Value of Assets and Liabilities - Fair Value Assumptions for Borrower Loans, Loans Held for Sale and Notes (Details) $ in Thousands		Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value	[1]	$ 414,877	$ 634,019
Notes, at Fair Value		206,931	244,171
Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value		208,044	245,137
Notes, at Fair Value		206,931	244,171
Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes, at Fair Value		206,931	244,171
Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value			245,137
Notes, at Fair Value		206,931	244,171
Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value		667,320	776,045
Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower Loans, at Fair Value		208,044	245,137
Discount rate assumption | 100 basis point increase | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		205,143	241,927
Discount rate assumption | 100 basis point increase | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			242,888
Notes		205,143	241,927
Discount rate assumption | 100 basis point increase | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		661,563	768,924
Discount rate assumption | 100 basis point increase | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		206,249	242,888
Discount rate assumption | 200 basis point incease | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		203,396	239,737
Discount rate assumption | 200 basis point incease | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			240,691
Notes		203,396	239,737
Discount rate assumption | 200 basis point incease | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		655,937	761,971
Discount rate assumption | 200 basis point incease | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		204,495	240,691
Discount rate assumption | 100 basis point decrease | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		208,761	246,471
Discount rate assumption | 100 basis point decrease | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			247,442
Notes		208,761	246,471
Discount rate assumption | 100 basis point decrease | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		673,214	783,344
Discount rate assumption | 100 basis point decrease | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		209,881	247,442
Discount rate assumption | 200 basis point decrease | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		210,635	248,828
Discount rate assumption | 200 basis point decrease | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			249,805
Notes		210,635	248,828
Discount rate assumption | 200 basis point decrease | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		679,249	790,823
Discount rate assumption | 200 basis point decrease | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		211,763	249,805
Default rate assumption | 10 percent increase | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		204,777	240,958
Default rate assumption | 10 percent increase | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			241,930
Notes		204,777	240,958
Default rate assumption | 10 percent increase | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		660,416	765,894
Default rate assumption | 10 percent increase | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		205,891	241,930
Default rate assumption | 20 percent increase | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		202,634	237,831
Default rate assumption | 20 percent increase | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			238,807
Notes		202,634	237,831
Default rate assumption | 20 percent increase | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		653,543	756,007
Default rate assumption | 20 percent increase | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		203,749	238,807
Default rate assumption | 10 percent decrease | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		209,093	247,489
Default rate assumption | 10 percent decrease | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			248,453
Notes		209,093	247,489
Default rate assumption | 10 percent decrease | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		674,253	786,541
Default rate assumption | 10 percent decrease | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		210,205	248,453
Default rate assumption | 20 percent decrease | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Notes		211,266	250,817
Default rate assumption | 20 percent decrease | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans			251,777
Notes		211,266	250,817
Default rate assumption | 20 percent decrease | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		681,220	797,065
Default rate assumption | 20 percent decrease | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrower loans		$ 212,377	$ 251,777
Discount rate
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1278	0.0959
Discount rate | Discount rate assumption | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1050	0.0643
Discount rate | Discount rate assumption | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1050	0.0643
Discount rate | Discount rate assumption | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.0957	0.0700
Discount rate | Discount rate assumption | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1050	0.0643
Default rate
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1210	0.1012
Default rate | Default rate assumption | Senior Notes
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1290	0.1368
Default rate | Default rate assumption | Senior Notes | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1290	0.1368
Default rate | Default rate assumption | Borrower loans and loans held for sale
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1250	0.1263
Default rate | Default rate assumption | Borrower loans and loans held for sale | Prosper Funding LLC
Fair Value Inputs Assets Quantitative Information [Line Items]
Fair value assumptions		0.1290	0.1368
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.

Fair Value of Assets and Lia_11

Fair Value of Assets and Liabilities - Fair Value Assumptions for Certificates Issued by Securitization Trust (Details) $ in Thousands		Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Certificates Issued by Securitization Trust, at Fair Value	[1]	$ 26,781	$ 52,168
Level 3 Inputs
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Certificates Issued by Securitization Trust, at Fair Value		26,781	52,168
Discount rate assumption | 100 basis point increase
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		26,560	51,813
Discount rate assumption | 200 basis point incease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		26,345	51,466
Discount rate assumption | 100 basis point decrease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		27,007	52,533
Discount rate assumption | 200 basis point decrease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		27,240	52,909
Default rate assumption | 10 percent increase
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		25,330	48,986
Default rate assumption | 20 percent increase
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		23,878	45,926
Default rate assumption | 10 percent decrease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		28,222	55,369
Default rate assumption | 20 percent decrease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		29,665	58,613
Prepayment rate assumption | 10 percent increase
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		26,815	52,085
Prepayment rate assumption | 20 percent increase
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		26,852	52,008
Prepayment rate assumption | 10 percent decrease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		26,763	52,253
Prepayment rate assumption | 20 percent decrease
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected fair value with change in assumptions		$ 26,749	$ 52,340
Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement inputs		0.1278	0.0959
Default rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement inputs		0.1210	0.1012
Prepayment rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair value measurement inputs		0.2003	0.2141
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.

Fair Value of Assets and Lia_12

Fair Value of Assets and Liabilities - Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Servicing Assets And Liabilities Fair Value [Line Items]
Servicing Assets	$ 9,306	$ 12,602
Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Servicing Assets	11,265	14,888
Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Servicing Assets	9,306	12,602
Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Servicing Assets	11,265	14,888
Market servicing rate | Servicing Assets | Market servicing rate increase of 0.025%
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	8,746	11,825
Market servicing rate | Servicing Assets | Market servicing rate increase of 0.025% | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	10,588	13,966
Market servicing rate | Servicing Assets | Market servicing rate decrease of 0.025%
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	9,865	13,387
Market servicing rate | Servicing Assets | Market servicing rate decrease of 0.025% | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	11,943	15,811
Prepayment rate assumption | Servicing Assets | Applying a 1.1 multiplier to prepayment rate
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	9,124	12,348
Prepayment rate assumption | Servicing Assets | Applying a 1.1 multiplier to prepayment rate | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	11,045	14,583
Prepayment rate assumption | Servicing Assets | Applying a 0.9 multiplier to prepayment rate
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	9,489	12,868
Prepayment rate assumption | Servicing Assets | Applying a 0.9 multiplier to prepayment rate | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	11,488	15,197
Default rate assumption | Servicing Assets | Applying a 1.1 multiplier to default rate
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	9,176	12,377
Default rate assumption | Servicing Assets | Applying a 1.1 multiplier to default rate | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	11,109	14,618
Default rate assumption | Servicing Assets | Applying a 0.9 multiplier to default rate
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	9,435	12,840
Default rate assumption | Servicing Assets | Applying a 0.9 multiplier to default rate | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Expected fair value with change in assumptions	$ 11,422	$ 15,165
Market servicing rate | Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Valuation techniques	0.634%	0.625%
Market servicing rate | Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Valuation techniques	0.634%	0.625%
Prepayment rate | Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Valuation techniques	20.13%	20.99%
Prepayment rate | Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Valuation techniques	20.13%	20.99%
Default rate | Servicing Assets
Servicing Assets And Liabilities Fair Value [Line Items]
Valuation techniques	13.13%	12.67%
Default rate | Servicing Assets | Prosper Funding LLC
Servicing Assets And Liabilities Fair Value [Line Items]
Valuation techniques	13.13%	12.67%

Fair Value of Assets and Lia_13

Fair Value of Assets and Liabilities - Schedule of Prosper's and Prosper Funding's Estimated Fair Value of Servicing Assets and Liabilities - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Servicing rate increase	0.025%
Servicing rate decrease	0.025%
Prepayment rate assumption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Prepayment rate increase	1.10%
Prepayment rate decrease	0.90%
Default rate assumption
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Default rate increase	1.10%
Default rate decrease	0.90%

Fair Value of Assets and Lia_14

Fair Value of Assets and Liabilities - Financial Instruments, Assets and Liabilities not Recorded at Fair Value (Details) - USD ($) $ in Thousands		Sep. 30, 2020		Dec. 31, 2019		Sep. 30, 2019
Assets
Cash and Cash Equivalents		$ 45,898		$ 64,635		$ 55,300
Restricted Cash		135,826	[1]	155,773	[1]	$ 158,302
Accounts Receivable	[1]	533		1,695
Total Assets		931,520		1,084,828
Liabilities:
Accounts Payable and Accrued Liabilities		14,600		19,937
Payable to Investors		95,887		101,092
Notes Issued by Securitization Trust	[1]	192,829		347,662
Warehouse Lines	[1]	226,784		131,583
Total Liabilities		876,402		1,068,335
Carrying Amount
Assets
Total Assets		182,257		222,103
Liabilities:
Total Liabilities		530,100		600,274
Balance at Fair Value
Assets
Cash and Cash Equivalents		45,898		64,635
Restricted Cash		135,826		155,773
Accounts Receivable		533		1,695
Total Assets		182,257		222,103
Liabilities:
Accounts Payable and Accrued Liabilities		14,600		19,937
Payable to Investors		95,887		101,092
Notes Issued by Securitization Trust		193,713		353,028
Warehouse Lines		226,267		131,090
Total Liabilities		530,467		605,147
Level 1 Inputs
Assets
Cash and Cash Equivalents		45,898		64,635
Restricted Cash		0		0
Accounts Receivable		0		0
Total Assets		45,898		64,635
Liabilities:
Accounts Payable and Accrued Liabilities		0		0
Payable to Investors		0		0
Notes Issued by Securitization Trust		0		0
Warehouse Lines		0		0
Total Liabilities		0		0
Level 2 Inputs
Assets
Cash and Cash Equivalents		0		0
Restricted Cash		135,826		155,773
Accounts Receivable		533		1,695
Total Assets		136,359		157,468
Liabilities:
Accounts Payable and Accrued Liabilities		14,600		19,937
Payable to Investors		95,887		101,092
Notes Issued by Securitization Trust		193,713		353,028
Warehouse Lines		226,267		131,090
Total Liabilities		530,467		605,147
Level 3 Inputs
Assets
Cash and Cash Equivalents		0		0
Restricted Cash		0		0
Accounts Receivable		0		0
Total Assets		0		0
Liabilities:
Accounts Payable and Accrued Liabilities		0		0
Payable to Investors		0		0
Notes Issued by Securitization Trust		0		0
Warehouse Lines		0		0
Total Liabilities		$ 0		$ 0
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Goodwill And Other Intangible Assets [Line Items]
Goodwill	$ 36,368,000		$ 36,368,000		$ 36,368,000
Goodwill impairment			0	$ 0
Intangible assets, net	555,000		555,000		$ 720,000
Amortization of intangible assets	100,000	$ 100,000	200,000	$ 200,000
User base and customer relationships
Goodwill And Other Intangible Assets [Line Items]
Intangible assets, net	$ 555,000		$ 555,000
Intangible assets amortized period			4 years 7 months 6 days
User base and customer relationships | Minimum
Goodwill And Other Intangible Assets [Line Items]
Intangible assets amortized period	3 years
User base and customer relationships | Maximum
Goodwill And Other Intangible Assets [Line Items]
Intangible assets amortized period	10 years

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Summary of Other Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 8,170
Accumulated Amortization	(7,615)
Net Carrying Value	555	$ 720
Developed technology
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	3,060
Accumulated Amortization	(3,060)
Net Carrying Value	0
User base and customer relationships
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	5,050
Accumulated Amortization	(4,495)
Net Carrying Value	$ 555
Remaining Useful Life (In Years)	4 years 7 months 6 days
Brand name
Finite Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 60
Accumulated Amortization	(60)
Net Carrying Value	$ 0

Goodwill And Other Intangible_5

Goodwill And Other Intangible Assets - Summary of Estimated Amortization of Purchased Intangible Assets (Details) $ in Thousands	Sep. 30, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
2020 (remainder thereof)	$ 55
2021	172
2022	136
2023	107
2024	85
Total	$ 555

Other Liabilities (Details)

Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Other Liabilities [Abstract]
Operating lease liabilities	$ 14,505	$ 17,507
PPP loan	8,484	0
Loan trailing fee	2,262	2,997
Deferred income tax liability	507	405
Deferred revenue	90	241
Other	370	576
Total Other Liabilities	$ 26,218	$ 21,726

Debt (Details)

Debt (Details)		Jun. 20, 2019	Mar. 28, 2019USD ($)	Apr. 30, 2019	Sep. 30, 2020USD ($)	Apr. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Jun. 12, 2018USD ($)
Line of Credit Facility [Line Items]
Loans Held for Sale	[1]				$ 252,443,000		$ 142,026,000
Warehouse Lines	[1]				226,784,000		131,583,000
PPP loan					8,484,000		$ 0
Warehouse Agreement | Revolving Credit Facility
Line of Credit Facility [Line Items]
Minimum tangible net worth					25,000,000
Minimum net liquidity					$ 15,000,000
Maximum leverage ratio					5
PWIT | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity					$ 200,000,000			$ 100,000,000
Repayment period		24 months
Advance rate		89.00%
Commitment fee percent		0.50%
Loans Held for Sale					117,100,000
Undrawn portion					99,700,000
Capitalized debt issuance cost					1,800,000
Warehouse Lines					100,300,000
PWIIT | Revolving Credit Facility
Line of Credit Facility [Line Items]
Maximum borrowing capacity			$ 300,000,000
Repayment period			24 months
Advance rate			90.00%
Commitment fee percent			0.50%
Loans Held for Sale					141,400,000
Undrawn portion					173,500,000
Capitalized debt issuance cost					2,100,000
Warehouse Lines					126,500,000
PPP Loan
Line of Credit Facility [Line Items]
Loan at time of issuance						$ 8,400,000
Stated interest rate						1.00%
Remaining contractual term (in years)				2 years
PPP loan					$ 8,500,000
LIBOR | PWIT | Revolving Credit Facility
Line of Credit Facility [Line Items]
Interest rate		2.90%
LIBOR | PWIIT | Revolving Credit Facility
Line of Credit Facility [Line Items]
Interest rate			2.90%
Increase to basis spread			0.375%
[1]	Includes amounts in consolidated variable interest entities (VIEs) presented separately in the table below.

Net Income (Loss) Per Share - B

Net Income (Loss) Per Share - Basic and Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net (Loss) Income	$ (2,025)	$ 17,641	$ 21,130	$ 10,769	$ (569)	$ (22,714)	$ 36,746	$ (12,514)
Plus: Return on Share Purchase	2,381			0			2,381	0
Less: Net Income Allocated to Participating Securities	(255)			(7,994)			(28,814)	0
Net Income (Loss) Attributable to Common Stockholders	$ 101			$ 2,775			$ 10,313	$ (12,514)
Denominator:
Weighted average shares used in computing net income (loss) per share - basic	68,485,173			70,606,805			68,465,046	70,532,641
Effect of dilutive securities:
Stock options (in shares)	14,902,171			1,939,105			50,778,284	0
Convertible preferred stock warrants (in shares)	213,264,845			213,264,845			213,264,845	0
Weighted average shares used in computing diluted net income (loss) per share - diluted	296,652,189			285,810,755			332,508,175	70,532,641
Net Income (Loss) Per Share - Basic (in dollars per share)	$ 0			$ 0.04			$ 0.15	$ (0.18)
Net Income (Loss) Per Share - Diluted (in dollars per share)	$ 0			$ 0.01			$ 0.03	$ (0.18)

Net Income (Loss) Per Share - C

Net Income (Loss) Per Share - Common Stock Equivalents Excluded from Computation of Diluted Net Income (Loss) Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net income (loss) per common share computation (in shares)	241,231,932	502,194,544	223,469,804	502,013,084
Convertible preferred stock issued and outstanding (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net income (loss) per common share computation (in shares)	181,761,442	214,637,925	200,261,761	214,637,925
Stock options issued and outstanding (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net income (loss) per common share computation (in shares)	58,390,141	73,211,425	22,127,694	73,029,965
Warrants issued and outstanding (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net income (loss) per common share computation (in shares)	1,080,349	1,080,349	1,080,349	1,080,349
Series E-1 convertible preferred stock warrants (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net income (loss) per common share computation (in shares)	0	35,544,141	0	35,544,141
Series F convertible preferred stock warrants (in shares)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents excluded from diluted net income (loss) per common share computation (in shares)	0	177,720,704	0	177,720,704

Convertible Preferred Stock, _3

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Additional Information (Details)	Jul. 21, 2020shares	Dec. 16, 2016	Feb. 16, 2016	Sep. 30, 2020USD ($)$ / sharesshares	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)time$ / sharesshares	Sep. 30, 2019USD ($)	Dec. 31, 2019$ / sharesshares	Sep. 20, 2017$ / sharesshares	Feb. 27, 2017$ / sharesshares
Class of Stock [Line Items]
Common and preferred stock, shares authorized (in shares)									1,069,760,848
Common stock, authorized (in shares)				625,000,000		625,000,000		625,000,000	625,000,000
Common stock, par value (in dollars per share) | $ / shares				$ 0.01		$ 0.01		$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)				444,760,848		444,760,848		444,760,848	444,760,848
Preferred stock, par value (in dollars per share) | $ / shares									$ 0.01
Common stock, issued (in shares)				69,794,521		69,794,521		69,387,836
Common stock, outstanding (in shares)				68,858,586		68,858,586		68,451,901
Convertible Preferred Stock Held by Consolidated VIE
Class of Stock [Line Items]
Purchase of convertible preferred stock by consolidated VIE Prosper Grantor Trust (in shares)				51,247,915
Common Stock
Class of Stock [Line Items]
Stock split conversion ratio of 5-for-1			5
Exercise of stock options (in shares)						406,685
Cash proceeds | $						$ 9,000
Series A
Class of Stock [Line Items]
Conversion ratio				1		1
Times the original issue | time						3
Liquidation preference (in dollars per share) | $ / shares				$ 0.29		$ 0.29
Preferred stock, shares authorized (in shares)				68,558,220		68,558,220
Series A | Convertible Preferred Stock Held by Consolidated VIE
Class of Stock [Line Items]
Purchase of convertible preferred stock by consolidated VIE Prosper Grantor Trust (in shares)	34,670,420
Series B
Class of Stock [Line Items]
IPO value (at least) | $						$ 2,000,000,000
Aggregate proceeds (at least) | $						$ 100,000,000
Voting power (at least)						60.00%
Liquidation preference (in dollars per share) | $ / shares				$ 0.60		$ 0.60
Preferred stock, shares authorized (in shares)				35,775,880		35,775,880
Series B | Convertible Preferred Stock Held by Consolidated VIE
Class of Stock [Line Items]
Purchase of convertible preferred stock by consolidated VIE Prosper Grantor Trust (in shares)	16,577,495
Series A-1
Class of Stock [Line Items]
Voting power (at least)						14.00%
Conversion ratio				1,000,000		1,000,000
Liquidation preference (in dollars per share) | $ / shares				$ 2		$ 2
Preferred stock, shares authorized (in shares)				24,760,915		24,760,915
Series D
Class of Stock [Line Items]
Voting power (at least)						60.00%
Liquidation preference (in dollars per share) | $ / shares				$ 6.91		$ 6.91
Series E1 and E2 Preferred Stock
Class of Stock [Line Items]
Voting power (at least)						60.00%
Series G
Class of Stock [Line Items]
Voting power (at least)						60.00%
Conversion ratio				1.36		1.36
Liquidation preference (in dollars per share) | $ / shares				$ 1.34		$ 1.34
Preferred stock, shares authorized (in shares)				37,249,497		37,249,497
Series C
Class of Stock [Line Items]
Liquidation preference (in dollars per share) | $ / shares				$ 2.87		$ 2.87
Preferred stock, shares authorized (in shares)				24,404,770		24,404,770
Series E-1
Class of Stock [Line Items]
Liquidation preference (in dollars per share) | $ / shares				$ 0.84		$ 0.84
Warrant to purchase (in shares)										15,277,006
Warrant expiration period		10 years
Income (expense) amount | $				$ (2,500,000)	$ 1,800,000	$ 10,300,000	$ 700,000
Preferred stock, shares authorized (in shares)				35,544,141		35,544,141
Series E-2
Class of Stock [Line Items]
Preferred stock, liquidation preference, conversion basis						0.666666666666667
Preferred stock, liquidation preference, conversion basis, after payment						0.333333333333333
Liquidation preference (in dollars per share) | $ / shares				$ 0.84		$ 0.84
Preferred stock, shares authorized (in shares)				16,858,078		16,858,078
Series F
Class of Stock [Line Items]
Voting power (at least)						60.00%
Preferred stock, liquidation preference, conversion basis						0.666666666666667
Preferred stock, liquidation preference, conversion basis, after payment						0.333333333333333
Liquidation preference (in dollars per share) | $ / shares				$ 0.84		$ 0.84
Income (expense) amount | $				$ (8,900,000)	$ 12,400,000	$ 53,300,000	$ 8,100,000
Exercise price (in dollars per share) | $ / shares										$ 0.01
Preferred stock, shares authorized (in shares)				177,720,707		177,720,707
Consortium Purchase Agreement | Series F Warrant
Class of Stock [Line Items]
Warrant to purchase (in shares)										177,720,706
Exercise price (in dollars per share) | $ / shares										$ 0.01

Convertible Preferred Stock, _4

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Summary of Shares Authorized, Issued, Outstanding, Par Value and Liquidation Preference of Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 20, 2017
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01			$ 0.01
Convertible preferred stock, authorized (in shares)	444,760,848			444,760,848					444,760,848
Convertible preferred stock, issued (in shares)	209,613,570			209,613,570
Convertible preferred stock, outstanding (in shares)	209,613,570			209,613,570
Liquidation Preference, Outstanding Shares	$ 370,456			$ 370,456
Convertible Preferred Stock Held by Consolidated VIE
Class of Stock [Line Items]
Convertible preferred stock, outstanding (in shares)	(51,247,915)	0	0	0	0	0	0	0
Series A
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	68,558,220
Convertible preferred stock, issued (in shares)	66,428,185
Convertible preferred stock, outstanding (in shares)	66,428,185
Liquidation Preference, Outstanding Shares	$ 19,160
Series A | Convertible Preferred Stock Held by Consolidated VIE
Class of Stock [Line Items]
Convertible preferred stock, issued (in shares)	34,670,420
Convertible preferred stock, outstanding (in shares)	34,670,420
Series A-1
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	24,760,915
Convertible preferred stock, issued (in shares)	22,515,315
Convertible preferred stock, outstanding (in shares)	22,515,315
Liquidation Preference, Outstanding Shares	$ 45,031
Series B
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	35,775,880
Convertible preferred stock, issued (in shares)	35,127,160
Convertible preferred stock, outstanding (in shares)	35,127,160
Liquidation Preference, Outstanding Shares	$ 21,190
Series B | Convertible Preferred Stock Held by Consolidated VIE
Class of Stock [Line Items]
Convertible preferred stock, issued (in shares)	16,577,495
Convertible preferred stock, outstanding (in shares)	16,577,495
Series C
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	24,404,770
Convertible preferred stock, issued (in shares)	24,404,770
Convertible preferred stock, outstanding (in shares)	24,404,770
Liquidation Preference, Outstanding Shares	$ 70,075
Series D
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	23,888,640
Convertible preferred stock, issued (in shares)	23,888,640
Convertible preferred stock, outstanding (in shares)	23,888,640
Liquidation Preference, Outstanding Shares	$ 165,000
Series E-1
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	35,544,141
Convertible preferred stock, issued (in shares)	0
Convertible preferred stock, outstanding (in shares)	0
Liquidation Preference, Outstanding Shares	$ 0
Series E-2
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	16,858,078
Convertible preferred stock, issued (in shares)	0
Convertible preferred stock, outstanding (in shares)	0
Liquidation Preference, Outstanding Shares	$ 0
Series F
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	177,720,707
Convertible preferred stock, issued (in shares)	3
Convertible preferred stock, outstanding (in shares)	3
Liquidation Preference, Outstanding Shares	$ 0
Series G
Class of Stock [Line Items]
Convertible preferred stock, par value (in dollars per share)	$ 0.01
Convertible preferred stock, authorized (in shares)	37,249,497
Convertible preferred stock, issued (in shares)	37,249,497
Convertible preferred stock, outstanding (in shares)	37,249,497
Liquidation Preference, Outstanding Shares	$ 50,000

Convertible Preferred Stock, _5

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Schedule of Assumptions Used (Details)	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Volatility | Series E-1
Class of Stock [Line Items]
Fair value assumptions	0.660	0.460
Volatility | Series F
Class of Stock [Line Items]
Fair value assumptions	0.660	0.460
Risk-free interest rate | Series E-1
Class of Stock [Line Items]
Fair value assumptions	0.0020	0.0160
Risk-free interest rate | Series F
Class of Stock [Line Items]
Fair value assumptions	0.0020	0.0160
Expected term (in years) | Series E-1
Class of Stock [Line Items]
Remaining contractual term (in years)	2 years 9 months	2 years 9 months
Expected term (in years) | Series F
Class of Stock [Line Items]
Remaining contractual term (in years)	2 years 9 months	2 years 9 months
Dividend yield | Series E-1
Class of Stock [Line Items]
Fair value assumptions	0	0
Dividend yield | Series F
Class of Stock [Line Items]
Fair value assumptions	0	0

Convertible Preferred Stock, _6

Convertible Preferred Stock, Warrant Liability and Stockholders’ Deficit - Warrant Liability (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Warrants or Rights [Roll Forward]
Change in fair value	$ (63,624)	$ (8,890)
Convertible Preferred Stock Warrant
Warrants or Rights [Roll Forward]
Beginning balance	149,996	143,679
Warrants Vested		17,553
Change in fair value	(63,624)	(8,890)
Ending balance	$ 86,372	$ 152,342

Share Based Incentive Plan an_3

Share Based Incentive Plan and Compensation - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Plan repricing, cost	$ 400,000		$ 400,000
Plan repricing, unamortized cost	$ 100,000		$ 100,000
Plan repricing, unamortized cost, vesting period			2 years 1 month 6 days
Options outstanding, term			7 years 3 months 7 days
Dividend yield	0.00%	0.00%	0.00%	0.00%
Internal-use software and website development costs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation capitalized	$ 100,000	$ 100,000	$ 200,000	$ 300,000
Stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized cost of unvested share-based compensation awards.	0		$ 0
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average vesting period			1 year 10 months 24 days
Unamortized expense related to unvested stock-based awards	$ 2,300,000		$ 2,300,000
RSUs | Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			3 years
RSUs | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period			4 years

Share Based Incentive Plan an_4

Share Based Incentive Plan and Compensation - Summarized Option Activity under Option Plan (Details) - 2005 Stock Plan and 2015 Stock Option Plan	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Options Issued and Outstanding
Beginning Balance (in shares) | shares	76,236,757
Options issued (in shares) | shares	8,308,000
Options exercised (in shares) | shares	(406,685)
Options forfeited (in shares) | shares	(6,724,169)
Options expired (in shares) | shares	(3,351,580)
Ending balance (in shares) | shares	74,062,323
Options vested and expected to vest (in shares) | shares	59,837,480
Options vested and exercisable (in shares) | shares	50,344,747
Weighted- Average Exercise Price
Beginning balance (in dollars per share) | $ / shares	$ 0.31
Options issued (in dollars per share) | $ / shares	0.08
Options exercised (in dollars per share) | $ / shares	0.02
Options forfeited (in dollars per share) | $ / shares	0.34
Options expired (in dollars per share) | $ / shares	0.13
Ending balance (in dollars per share) | $ / shares	0.02
Options vested and expected to vest (in dollars per share) | $ / shares	0.02
Options vested and exercisable (in dollars per share) | $ / shares	$ 0.02

Share Based Incentive Plan an_5

Share Based Incentive Plan and Compensation - Fair Value of Stock Option Awards (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair value of stock option awards [Abstract]
Volatility of common stock	57.32%	46.72%	52.66%	46.72%
Risk-free interest rate	0.37%	1.57%	0.51%	2.24%
Expected life (in years)	6 years	6 years	6 years	5 years 10 months 24 days
Dividend yield	0.00%	0.00%	0.00%	0.00%

Share Based Incentive Plan an_6

Share Based Incentive Plan and Compensation - Summarized Activities for the Company's RSU's (Details) - RSUs	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Number of Shares
Unvested, beginning balance (in shares) | shares	4,803,141
Forfeited (in shares) | shares	(142,000)
Unvested, ending balance (in shares) | shares	4,661,141
Weighted-Average Grant Date Fair Value
Unvested, beginning balance (in dollars per share) | $ / shares	$ 0.95
Forfeited (in dollars per share) | $ / shares	2.18
Unvested, ending balance (in dollars per share) | $ / shares	$ 0.91

Share Based Incentive Plan an_7

Share Based Incentive Plan and Compensation - Stock Based Compensation Included in Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 786	$ 988	$ 1,683	$ 3,838
Origination and servicing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	53	73	124	377
Sales and marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	25	71	51	216
General and administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total stock-based compensation	$ 708	$ 844	$ 1,508	$ 3,245

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Taxes [Line Items]
Income tax expense	$ 34,000	$ 29,000	$ 102,000	$ 87,000
Prosper Funding LLC
Income Taxes [Line Items]
Income tax expense			$ 0	$ 0
Net effective tax rate			0.00%

Consortium Purchase Agreement (

Consortium Purchase Agreement (Details) - Consortium Purchase Agreement - USD ($)	9 Months Ended
	Sep. 30, 2020	May 31, 2019	Feb. 27, 2017
Other Commitments [Line Items]
Commitment to purchase borrower loans (up to)			$ 5,000,000,000
Loans acquired		$ 3,300,000,000
Warrants vested (in shares)		177,700,000
Amount settled with rebates	$ 300,000,000
Series F Warrant
Other Commitments [Line Items]
Warrant to purchase up to (in shares)			3
Warrant to purchase (in shares)			177,720,706
Exercise price (in dollars per share)			$ 0.01

Leases - Additional Information

Leases - Additional Information (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessee, Lease, Description [Line Items]
Renewal term	5 years			5 years
Rental expense under operating lease arrangements	$ 1,200,000		$ 1,400,000	$ 4,200,000	$ 4,100,000
Sublease income	100,000		$ 200,000	400,000	600,000
Impairment of Operating Lease Right-of-Use Asset	$ 0	$ 200,000		$ 228,000	$ 0
Operating lease liability, location	us-gaap:OtherLiabilities			us-gaap:OtherLiabilities
Minimum
Lessee, Lease, Description [Line Items]
Operating lease contract term	1 year			1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease contract term	6 years			6 years

Leases - Operating Lease Right-

Leases - Operating Lease Right-of-Use Assets (Details) $ in Thousands	Sep. 30, 2020USD ($)
Lessee, Lease, Description [Line Items]
Gross Carrying Value	$ 15,984
Accumulated Amortization	5,802
Net Carrying Value	10,182
ROU Assets - Office buildings
Lessee, Lease, Description [Line Items]
Gross Carrying Value	15,694
Accumulated Amortization	5,796
Net Carrying Value	9,898
ROU Assets - Other
Lessee, Lease, Description [Line Items]
Gross Carrying Value	290
Accumulated Amortization	6
Net Carrying Value	$ 284

Leases - Schedule of Lease Matu

Leases - Schedule of Lease Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Schedule of Lease Maturity
Remainder of 2020	$ 1,338
2021	5,279
2022	5,121
2023	1,562
2024	871
Thereafter	1,820
Total future minimum lease payments	15,991
Less imputed interest	(1,486)
Present value of future minimum lease payments	$ 14,505	$ 17,507

Leases - Other Information Rela

Leases - Other Information Related to Leases (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Leases [Abstract]
Cash paid for operating leases year-to-date	$ 3,996
Right of use assets obtained in exchange for new operating lease obligations	$ 290
Weighted average remaining lease term (in years)	3 years 6 months 18 days
Weighted average discount rate	5.50%

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	Apr. 19, 2019	Apr. 30, 2019	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019
Commitments And Contingencies [Line Items]
Designated Amount for loans (less than)			$ 143,500	$ 143,500
Minimum fee, remaining in current year			400,000	400,000
Minimum fee, 2021			1,700,000	1,700,000
Minimum fee, 2022			100,000	100,000
Minimum liquidity covenant			15,000,000	15,000,000
Purchase of borrower loans			12,900,000
Maximum potential future payments			2,400,000,000	2,400,000,000
Accrued repurchase and indemnification obligation			300,000	300,000	$ 400,000
Amount awarded to other party	$ 3,000,000
Accrued penalty		$ 3,000,000
Prosper Funding LLC
Commitments And Contingencies [Line Items]
Designated Amount for loans (less than)			143,500	143,500
Minimum fee, remaining in current year			400,000	400,000
Minimum fee, 2021			1,700,000	1,700,000
Minimum fee, 2022			100,000	100,000
Minimum liquidity covenant			15,000,000	15,000,000
Purchase of borrower loans				12,900,000
Maximum potential future payments			2,900,000,000	2,900,000,000
Accrued repurchase and indemnification obligation			$ 300,000	$ 300,000	$ 400,000
Amount awarded to other party	$ 3,000,000
Accrued penalty		$ 3,000,000

Related Parties - Additional In

Related Parties - Additional Information (Details)	9 Months Ended
	Sep. 30, 2020
Related Party Transactions [Abstract]
Minimum percentage of voting securities considered for related parties	10.00%
Minimum percentage of stockholders considered for related parties	10.00%

Related Parties - Aggregate Amo

Related Parties - Aggregate Amount of Notes Purchased and the Income Earned (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	$ 48	$ 107	$ 291	$ 326
Interest Earned on Notes and Borrower Loans	15	14	47	41
Notes balance	586		586		$ 717
Prosper Funding LLC
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	7	6	19	17
Interest Earned on Notes and Borrower Loans	1	1	4	4
Notes balance	37		37		35
Executive officers and management
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	7	6	19	17
Interest Earned on Notes and Borrower Loans	1	1	4	4
Notes balance	37		37		35
Executive officers and management | Prosper Funding LLC
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	7	6	19	17
Interest Earned on Notes and Borrower Loans	1	1	4	4
Notes balance	37		37		35
Directors (excluding executive officers and management)
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	41	101	272	309
Interest Earned on Notes and Borrower Loans	14	13	43	37
Notes balance	549		549		682
Directors (excluding executive officers and management) | Prosper Funding LLC
Related Party Transaction [Line Items]
Aggregate Amount of Notes and Borrower Loans Purchased	0	0	0	0
Interest Earned on Notes and Borrower Loans	0	$ 0	0	$ 0
Notes balance	$ 0		$ 0		$ 0

Significant Concentrations (Det

Significant Concentrations (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Concentration Risk [Line Items]
Percentage of funds originating in channel			91.00%	93.00%
Party One
Concentration Risk [Line Items]
Percentage of loan purchased	26.70%	15.80%	17.70%	11.40%
Party Two
Concentration Risk [Line Items]
Percentage of loan purchased	15.00%	11.50%	16.40%
Warehouse VIE
Concentration Risk [Line Items]
Percentage of loan purchased	23.10%	18.80%	21.10%	11.70%