PDD (PDD) 20-F 24 Apr 20 2019 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Dec. 31, 2019shares
Document Type	20-F
Document Registration Statement	false
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Document Shell Company Report	false
Entity File Number	001-38591
Entity Registrant Name	Pinduoduo Inc.
Entity Incorporation, State or Country Code	E9
Entity Address, Address Line One	28/F, No. 533 Loushanguan Road, Changning District
Entity Address, City or Town	Shanghai
Entity Address, Postal Zip Code	200051
Entity Address, Country	CN
Title of 12(b) Security	American Depositary Shares
Trading Symbol	PDD
Security Exchange Name	NASDAQ
Entity Central Index Key	0001737806
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Document Accounting Standard	U.S. GAAP
Entity Emerging Growth Company	false
Entity Shell Company	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Business Contact [Member]
Entity Address, Address Line One	28/F, No. 533 Loushanguan Road, Changning District
Entity Address, City or Town	Shanghai
Entity Address, Postal Zip Code	200051
Entity Address, Country	CN
Contact Personnel Name	Jianchong Zhu
Contact Personnel Email Address	investor@pinduoduo.com
Class A ordinary shares
Entity Common Stock, Shares Outstanding	2,575,580,988
Class B ordinary shares
Entity Common Stock, Shares Outstanding	2,074,447,700

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2016CNY (¥)
Current assets
Cash and cash equivalents	$ 828,548	¥ 5,768,186	¥ 14,160,322	¥ 3,058,152
Restricted cash	3,961,285	27,577,671	16,379,364	9,370,849
Receivables from online payment platforms	150,963	1,050,974	247,586
Short-term investments	5,068,923	35,288,827	7,630,689
Amounts due from related parties	339,787	2,365,528	1,019,033
Prepayments and other current assets	136,499	950,277	953,989
Total current assets	10,486,005	73,001,463	40,390,983
Non-current assets
Property, equipment and software, net	5,928	41,273	29,075
Intangible asset	286,462	1,994,292	2,579,338
Right-of-use assets	74,289	517,188
Other non-current assets	72,269	503,120	182,667
Total non-current assets	438,948	3,055,873	2,791,080
Total Assets	10,924,953	76,057,336	43,182,063
Current liabilities
Amounts due to related parties (including amounts due to related parties of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of RMB458,147 and RMB1,502,892 (US$215,877) as of December 31, 2018 and 2019, respectively)	215,877	1,502,892	478,113
Customer advances and deferred revenues (including customer advances and deferred revenues of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of RMB190,382 and RMB605,969 (US$87,042) as of December 31, 2018 and 2019, respectively)	87,042	605,970	191,482
Payable to merchants (including payable to merchants of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of RMB17,275,934 and RMB29,657,227 (US$4,259,994) as of December 31, 2018 and 2019, respectively)	4,298,671	29,926,488	17,275,934
Accrued expenses and other liabilities (including accrued expenses and other liabilities of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of RMB1,500,951 and RMB3,420,728 (US$491,358) as of December 31, 2018 and 2019, respectively)	700,547	4,877,062	2,225,667
Merchant deposits (including merchant deposits of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of RMB4,188,273 and RMB7,840,912 (US$1,126,277) as of December 31, 2018 and 2019, respectively)	1,126,277	7,840,912	4,188,273
Short-term borrowings (including short-term borrowings of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of nil and RMB898,748 (US$129,097) as of December 31, 2018 and 2019, respectively)	129,097	898,748
Lease liabilities (including lease liabilities of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of nil and RMB90,523 (US$13,003) as of December 31, 2018 and 2019, respectively)	16,624	115,734
Total current liabilities	6,574,135	45,767,806	24,359,469
Convertible bonds	747,893	5,206,682
Lease liabilities (including lease liabilities of the consolidated VIE and its subsidiaries without recourse to the primary beneficiary of nil and RMB382,673 (US$54,968) as of December 31, 2018 and 2019, respectively)	61,564	428,593
Other non-current liabilities	1,061	7,389
Total non-current liabilities	810,518	5,642,664
Total liabilities	7,384,653	51,410,470	24,359,469
Shareholders' equity
Additional paid-in capital	5,960,233	41,493,949	29,114,527
Accumulated other comprehensive income	208,025	1,448,230	1,035,783
Accumulated deficits	(2,627,979)	(18,295,461)	(11,327,858)
Total shareholders' equity	3,540,300	24,646,866	18,822,594	¥ (991,958)	¥ (426,278)
Total liabilities and shareholders' equity	10,924,953	76,057,336	43,182,063
Class A ordinary shares
Shareholders' equity
Common Shares	12	84	78
Class B ordinary shares
Shareholders' equity
Common Shares	$ 9	¥ 64	¥ 64

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)shares	Dec. 31, 2018CNY (¥)shares
Amounts due to related parties	$ 215,877	¥ 1,502,892	¥ 478,113
Customer advances and deferred revenue	87,042	605,970	191,482
Payable to merchants	4,298,671	29,926,488	17,275,934
Accrued expenses and other liabilities	700,547	4,877,062	2,225,667
Merchant deposits	1,126,277	7,840,912	¥ 4,188,273
Short-term borrowings	129,097	898,748
Current portion of lease liabilities	16,624	115,734
Non-Current portion of Lease liabilities	$ 61,564	¥ 428,593
Ordinary shares, outstanding			4,455,688,688
Class A ordinary shares
Ordinary shares, par value | $ / shares	$ 0.000005
Ordinary shares, shares authorized	77,300,000,000	77,300,000,000	77,300,000,000
Ordinary shares, issued	2,575,580,988	2,575,580,988	2,381,240,988
Ordinary shares, outstanding	2,575,580,988	2,575,580,988	2,381,240,988
Class B ordinary shares
Ordinary shares, par value | $ / shares	$ 0.000005
Ordinary shares, shares authorized	2,200,000,000	2,200,000,000	2,200,000,000
Ordinary shares, issued	2,074,447,700	2,074,447,700	2,074,447,700
Ordinary shares, outstanding	2,074,447,700	2,074,447,700	2,074,447,700
Consolidated VIE
Amounts due to related parties	$ 215,877	¥ 1,502,892	¥ 458,147
Customer advances and deferred revenue	87,042	605,969	190,382
Payable to merchants	4,259,994	29,657,227	17,275,934
Accrued expenses and other liabilities	491,358	3,420,728	1,500,951
Merchant deposits	1,126,277	7,840,912	4,188,273
Short-term borrowings	129,097	898,748	0
Current portion of lease liabilities	13,003	90,523	0
Non-Current portion of Lease liabilities	$ 54,968	¥ 382,673	¥ 0

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)¥ / sharesshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2018CNY (¥)¥ / sharesshares	Dec. 31, 2017CNY (¥)¥ / sharesshares
Revenues
Revenues	$ 4,329,611	¥ 30,141,886		¥ 13,119,990	¥ 1,744,076
Costs of revenues
Total costs of revenues	(910,508)	(6,338,778)		(2,905,249)	(722,830)
Gross profit	3,419,103	23,803,108		10,214,741	1,021,246
Sales and marketing expenses	(3,903,337)	(27,174,249)		(13,441,813)	(1,344,582)
General and administrative expenses	(186,261)	(1,296,712)		(6,456,612)	(133,207)
Research and development expenses (including services received from a related party of RMB223,732 and RMB873,288(US$125,440) for the years ended December 31, 2018 and 2019, respectively)	(555,942)	(3,870,358)		(1,116,057)	(129,181)
Impairment of a long-term investment		0		0	(10,000)
Total operating expenses	(4,645,540)	(32,341,319)		(21,014,482)	(1,616,970)
Operating loss	(1,226,437)	(8,538,211)		(10,799,741)	(595,724)
Interest and investment gain, net	221,469	1,541,825		584,940	80,783
Interest expense	(20,951)	(145,858)
Foreign exchange (loss)/gain	9,075	63,179		10,037	(11,547)
Other income/(loss), net	11,891	82,786		(12,361)	1,373
Loss before income tax and share of results of equity investees	(1,004,953)	(6,996,279)		(10,217,125)	(525,115)
Share of results of equity investees	4,119	28,676
Net loss	(1,000,834)	(6,967,603)		(10,217,125)	(525,115)
Deemed distribution to certain holders of convertible preferred shares		(80,496)	$ (11,708)	(80,496)
Contribution from a holder of convertible preferred shares					26,413
Net loss attributable to ordinary shareholders	$ (1,000,834)	¥ (6,967,603)		¥ (10,297,621)	¥ (498,702)
Loss per share:
Basic | (per share)	$ (0.22)	¥ (1.51)		¥ (3.47)	¥ (0.28)
Diluted | (per share)	$ (0.22)	¥ (1.51)		¥ (3.47)	¥ (0.28)
Shares used in loss per share computation
Basic | shares	4,627,278,394	4,627,278,394	2,968,319,549	2,968,319,549	1,764,799,346
Diluted | shares	4,627,278,394	4,627,278,394	2,968,319,549	2,968,319,549	1,764,799,346
Other comprehensive (loss)/income, net of tax of nil
Foreign currency translation difference, net of tax of nil	$ 59,244	¥ 412,447		¥ 1,058,884	¥ (47,681)
Comprehensive loss	(941,590)	(6,555,156)		(9,158,241)	(572,796)
Online marketplace services
Revenues
Revenues	4,329,611	30,141,886		13,119,990	1,740,691
Costs of revenues
Total costs of revenues	$ (910,508)	¥ (6,338,778)		¥ (2,905,249)	(719,778)
Merchandise sales
Revenues
Revenues					3,385
Costs of revenues
Total costs of revenues					¥ (3,052)

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Other comprehensive income/(loss), tax		¥ 0	¥ 0
Foreign currency translation difference, tax		0	0
Research and development expenses
Services rendered from related party	$ 125,440	873,288	223,732
Online marketplace services
Services rendered from related party	$ 204,658	¥ 1,424,786	¥ 1,042,630

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' (DEFICITS)/EQUITY ¥ in Thousands, $ in Thousands	Ordinary sharesUSD ($)shares	Ordinary sharesCNY (¥)shares	Additional paid in capitalUSD ($)	Additional paid in capitalCNY (¥)	Accumulated other comprehensive (loss)/incomeUSD ($)	Accumulated other comprehensive (loss)/incomeCNY (¥)	Accumulated DeficitsUSD ($)	Accumulated DeficitsCNY (¥)	Class B ordinary sharesshares	USD ($)shares	CNY (¥)shares
Balance at beginning of the year at Dec. 31, 2016		¥ 56		¥ 21,531		¥ 24,580		¥ (472,445)			¥ (426,278)
Balance (in shares) at Dec. 31, 2016 | shares	1,815,200,000	1,815,200,000
Changes in equity
Net loss								(525,115)			(525,115)
Foreign currency translation difference						(47,681)					(47,681)
Repurchase and cancellation of Class B ordinary shares		¥ (2)		2				(32,677)			(32,677)
Repurchase and cancellation of Class B ordinary shares (in shares) | shares	(56,430,180)	(56,430,180)
Contribution from a holder of convertible preferred shares				26,413							26,413
Share-based compensation				13,380							13,380
Balance at end of the year at Dec. 31, 2017		¥ 54		61,326		(23,101)		(1,030,237)			¥ (991,958)
Balance (in shares) at Dec. 31, 2017 | shares	1,758,769,820	1,758,769,820								1,758,769,820	1,758,769,820
Changes in equity
Net loss								(10,217,125)			¥ (10,217,125)
Foreign currency translation difference						1,058,884					1,058,884
Deemed distribution to certain holders of convertible preferred shares								(80,496)			¥ (80,496)
Conversion of convertible preferred shares to ordinary shares (in shares) | shares										2,075,502,060	2,075,502,060
Initial public offering		¥ 13		11,523,618							¥ 11,523,631
Initial public offering (in shares) | shares										366,943,308	366,943,308
Contribution from a holder of convertible preferred shares		67		10,950,438							¥ 10,950,505
Share-based compensation		8		6,579,145							¥ 6,579,153
Share-based compensation (in shares) | shares										254,473,500	254,473,500
Balance at end of the year at Dec. 31, 2018		¥ 142		29,114,527		1,035,783		(11,327,858)			¥ 18,822,594
Balance (in shares) at Dec. 31, 2018 | shares	4,455,688,688	4,455,688,688							2,074,447,700	4,455,688,688	4,455,688,688
Changes in equity
Net loss								(6,967,603)		$ (1,000,834)	¥ (6,967,603)
Foreign currency translation difference						412,447				$ 59,244	412,447
Initial public offering		¥ 6		7,993,822							7,993,828
Initial public offering (in shares) | shares	193,740,000	193,740,000
Equity component of convertible bonds				1,827,894							¥ 1,827,894
Shares issued to depository bank | shares	600,000	600,000								600,000	600,000
Restricted share units vested | shares	(567,636)	(567,636)
Settlement of share-based compensation with shares held by depository bank | shares	(567,636)	(567,636)
Share-based compensation				2,557,706							¥ 2,557,706
Balance at end of the year at Dec. 31, 2019	$ 21	¥ 148	$ 5,960,233	¥ 41,493,949	$ 208,025	¥ 1,448,230	$ (2,627,979)	¥ (18,295,461)		$ 3,540,300	¥ 24,646,866
Balance (in shares) at Dec. 31, 2019 | shares	4,650,028,688	4,650,028,688							2,074,447,700

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
CASH FLOW FROM OPERATING ACTIVITIES
Net loss	$ (1,000,834)	¥ (6,967,603)	¥ (10,217,125)	¥ (525,115)
Interest expense	20,951	145,858
Provision for prepayments made on behalf of merchants	1,692	11,782	2,155
Depreciation and amortization	91,619	637,831	497,003	2,265
Lease expense to reduce right-of-use assets	10,515	73,206
Impairment of long-term investment		0	0	10,000
Interest and investment gain, net	(30,104)	(209,580)	(78,267)	(2,573)
Loss on disposal of property and equipment	25	175	13	64
Share-based compensation	367,392	2,557,706	6,841,573	13,380
Foreign exchange gain	(773)	(5,380)
Share of results of equity investees	(4,119)	(28,676)
Changes in operating assets and liabilities:
Receivables from online payment platforms	(115,399)	(803,388)	(159,413)	(77,891)
Amounts due from related parties	(127,390)	(886,863)	(576,121)	(350,265)
Prepayments and other current assets	1,788	12,449	(790,732)	(87,614)
Customer advances	59,537	414,488	135,029	54,299
Amounts due to related parties	147,200	1,024,779	402,056	51,081
Payable due to merchants	1,817,180	12,650,833	7,437,415	8,721,721
Accrued expenses and other liabilities	380,486	2,648,869	1,864,153	318,363
Merchant deposits	524,669	3,652,639	2,410,188	1,558,613
Right-of-use assets	(84,805)	(590,394)
Lease liabilities	78,188	544,327
Other non-current assets	(9,979)	(69,471)
Other non-current liabilities	1,061	7,389
Net cash provided by operating activities	2,128,900	14,820,976	7,767,927	9,686,328
CASH FLOW FROM INVESTING ACTIVITIES
Purchase of short-term investments	(7,534,202)	(52,451,615)	(7,516,370)	(1,393,000)
Proceeds from sales of short-term investments	3,561,957	24,797,630	50,000	1,633,000
Purchase of long-term investments	(30,754)	(214,100)	(184,637)
Proceeds from disposal of a long-term investment			5,000
Purchase of property, equipment and software	(3,941)	(27,436)	(27,331)	(8,921)
Proceeds from disposal of property and equipment	68	475	39	362
Loans to related parties	(66,022)	(459,632)		(159,790)
Repayments from related parties			159,790
(Loans to)/Repayments from third parties	5,027	35,000	(35,000)
Net cash provided by/(used in) investing activities	(4,067,867)	(28,319,678)	(7,548,509)	71,651
CASH FLOW FROM FINANCING ACTIVITIES
Proceeds from the initial public offering			11,879,944
Costs incurred for the initial public offering			(356,313)
Proceeds from follow-on offering	1,177,080	8,194,597
Costs incurred for the follow-on offering	(28,839)	(200,769)
Proceeds from issuance of convertible preferred shares			5,824,568	1,446,906
Costs incurred for the issuance of convertible preferred shares			(3,842)	(15,369)
Repurchase of Class B ordinary shares				(32,677)
Proceeds from issuance of convertible bonds	1,015,987	7,073,101
Costs incurred for the issuance of convertible bonds	(15,688)	(109,220)
Proceeds from short-term borrowings	128,850	897,022
Net cash provided by financing activities	2,277,390	15,854,731	17,344,357	1,398,860
Effect of exchange rate changes on cash, cash equivalents and restricted cash	64,659	450,142	546,910	(47,681)
Increase in cash, cash equivalents and restricted cash	403,082	2,806,171	18,110,685	11,109,158
Cash, cash equivalents and restricted cash at beginning of year	4,386,751	30,539,686	12,429,001	1,319,843
Cash, cash equivalents and restricted cash at end of year	4,789,833	33,345,857	30,539,686	12,429,001
Supplement disclosure of cash flow information:
Interest income received	174,013	1,211,443	433,390	52,150
Supplement disclosure of non-cash operating activities :
Recognition of right-of-use assets and lease liabilities	90,854	632,507
Supplement disclosure of non-cash investing activities:
Purchase of property, equipment and software included in accrued expenses and other liabilities	$ 310	¥ 2,160	1,319	¥ 198
Acquisition of intangible asset			¥ 2,852,370

CONSOLIDATED STATEMENTS OF CA_2

CONSOLIDATED STATEMENTS OF CASH FLOWS - Reconciliation of Cash, Cash Equivalents and Restricted Cash ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2016CNY (¥)
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	$ 828,548	¥ 5,768,186		¥ 14,160,322	¥ 3,058,152
Restricted cash	3,961,285	27,577,671		16,379,364	9,370,849
Total cash, cash equivalents and restricted cash in the statements of cash flows	$ 4,789,833	¥ 33,345,857	$ 4,386,751	¥ 30,539,686	¥ 12,429,001	¥ 1,319,843

Organization

Organization	12 Months Ended
	Dec. 31, 2019
Organization
Organization	1. Organization Pinduoduo Inc. (the ‘‘Company’’) was incorporated in the Cayman Islands on April 20, 2015 under the Cayman Islands Companies Law as an exempted company with limited liability. The Company through its consolidated subsidiaries, variable interest entity (the ‘‘VIE’’) and the subsidiaries of the VIE (collectively, the ‘‘Group’’) are principally engaged in the merchandise sales and the provision of online marketplace to help merchants leverage the power of the internet to engage with their customers in the People’s Republic of China (the ‘‘PRC’’ or ‘‘China’’). Due to the PRC legal restrictions on foreign ownership and investment in such business, the Company conducts its primary business operations through its VIE and subsidiaries of the VIE. The Company is ultimately controlled by Mr. Zheng Huang (the ‘‘Founder’’) since its establishment. As of December 31, 2019, the details of the Company’s major subsidiaries, consolidated VIE and the subsidiaries of the VIE are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Percentage of ​ ​ ​ Date of ​ Place of ​ ownership by the ​ Principal Entity ​ incorporation ​ incorporation ​ Company ​ activities ​ ​ ​ ​ ​ ​ Direct Indirect ​ ​ Subsidiaries: HongKong Walnut Street Limited ("Walnut HK") ​ April 28, 2015 Hong Kong 100 % — Holding company Hangzhou Weimi Network Technology Co., Ltd. ("Hangzhou Weimi" or the "WFOE") ​ May 28, 2015 PRC 100 % — Technology research and development Walnut Street (Shanghai) Information Technology Co., Ltd. ​ January 25,2018 PRC 100 % ​ Technology research and development Shenzhen Qianhai Xinzhijiang Information Technology Co., Ltd. (“Xinzhijiang”) ​ April 25, 2018 ​ PRC ​ 100 % — ​ E-commerce platform ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ VIE: ​ Hangzhou Aimi Network Technology Co., Ltd. ("Hangzhou Aimi" or the "VIE") ​ April 14, 2015 PRC — 100 % E-commerce platform ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ VIE’s subsidiary: ​ Shanghai Xunmeng Information Technology Co., Ltd. ("Shanghai Xunmeng") ​ January 9, 2014 PRC — 100 % E-commerce platform ​ In June 2016, the Company obtained 100% equity interest in Shanghai Xunmeng which was controlled by the Founder since its establishment. The transaction undertaken by the Company and the Founder to restructure the Group was accounted for as a legal reorganization of entities under common control in a manner similar to a pooling of interest using historical cost. The accompanying consolidated financial statements have been prepared as if the current corporate structure had been in existence throughout the periods presented. The VIE agreements The PRC laws and regulations currently place certain restrictions on foreign ownership of companies that engage in internet content and other restricted businesses. To comply with PRC laws and regulations, the Group conducts the majority of its business in China through the VIE and subsidiaries of the VIE. Despite the lack of technical majority ownership, the Company has effective control of the VIE through a series of contractual arrangements (the "Contractual Agreements’’) and a parent-subsidiary relationship exists between the Company and the VIE. The equity interests of the VIE are legally held by PRC individuals (the ‘‘Nominee Shareholders’’). Through the Contractual Agreements, the Nominee Shareholders of the VIE effectively assigned all of their voting rights underlying their equity interests in the VIE to the Company, via the WFOE, and therefore, the Company has the power to direct the activities of the VIE that most significantly impact its economic performance. The Company also has the right to receive economic benefits and obligations to absorb losses from the VIE, via the WFOE, that potentially could be significant to the VIE. Based on the above, the Company consolidates the VIE in accordance with SEC Regulation SX-3A-02 and ASC810-10, Consolidation: Overall. 1. Organization (Continued) The VIE agreements (Continued) The following is a summary of the Contractual Agreements: Exclusive Option Agreements Equity Pledge Agreement Shareholders’ Voting Rights Proxy Agreement Exclusive Consulting and Services Agreement 1. Organization (Continued) The VIE agreements (Continued) Financial support undertaking letter In the opinion of the Company’s management and PRC counsel, (i) the ownership structure of the Group, including its subsidiaries, the VIE and the subsidiaries of the VIE, is not in violation with any applicable PRC laws and (ii) each of the VIE agreements is legal, valid, binding and enforceable to each party of such agreements in accordance with its terms and applicable PRC Laws. However, uncertainties in the PRC legal system could cause the relevant regulatory authorities to find the current Contractual Agreements and businesses to be in violation of any existing or future PRC laws or regulations. If the Company, the WFOE or any of its current or future VIE are found in violation of any existing or future laws or regulations, or fail to obtain or maintain any of the required permits or approvals, the relevant PRC regulatory authorities would have broad discretion in dealing with such violations, which may include, but not limited to, revocation of business and operating licenses, being required to discontinue or restrict its business operations, restriction of the Group’s right to collect revenues, being required to restructure its operations, imposition of additional conditions or requirements with which the Group may not be able to comply, or other regulatory or enforcement actions against the Group that could be harmful to its business. The imposition of any of these or other penalties may result in a material and adverse effect on the Group’s ability to conduct its business. In addition, if the imposition of any of these penalties causes the Company to lose the rights to direct the activities of the VIE or the right to receive their economic benefits, the Company would no longer be able to consolidate the VIE. In addition, if the VIE or the Nominee Shareholders fail to perform their obligations under the Contractual Agreements, the Group may have to incur substantial costs and expend resources to enforce the primary beneficiary’ rights under the contracts. The Group may have to rely on legal remedies under PRC laws, including seeking specific performance or injunctive relief and claiming damages, which may not be effective. All of the Contractual Agreements are governed by PRC laws and provide for the resolution of disputes through arbitration in the PRC. Accordingly, these contracts would be interpreted in accordance with PRC laws and any disputes would be resolved in accordance with PRC legal procedures. The legal system in PRC is not as developed as in other jurisdictions, such as the United States. As a result, uncertainties in the PRC legal system could limit the Group’s ability to enforce these contractual arrangements. Under PRC laws, rulings by arbitrators are final, parties cannot appeal the arbitration results in courts, and prevailing parties may only enforce the arbitration awards in PRC courts through arbitration award recognition proceedings, which would incur additional expenses and delay. In the event the Group is unable to enforce the Contractual Agreements, the primary beneficiary may not be able to exert effective control over its VIE, and the Group’s ability to conduct its business may be negatively affected. The VIE and its subsidiaries contributed to 100%, 77.3% and 58.5% of the Group’s consolidated revenues for the years ended December 31, 2017, 2018 and 2019, respectively. As of December 31, 2018 and 2019, the VIE and its subsidiaries accounted for an aggregate of 53.1% and 54.1%, respectively of the consolidated total assets, and 96.9% and 86.4%, respectively of the consolidated total liabilities. 1. Organization (Continued) Other revenue-producing assets held by the VIE and its subsidiaries mainly include licenses, such as the internet content provision license and internally-developed intangible assets including trademarks, patents, copyrights and domain names. The following tables represent the financial information for the VIE as of December 31, 2018 and 2019 and for the years ended December 31, 2017, 2018 and 2019 before eliminating the inter-company balances and transactions between the VIE, the subsidiaries of the VIE and other entities within the Group: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ RMB RMB US$ ASSETS ​ ​ ​ ​ ​ ​ ​ Current assets Cash and cash equivalents 3,529,316 2,816,894 404,622 Restricted cash 16,379,364 27,528,793 3,954,264 Receivables from online payment platforms 247,586 1,050,974 150,963 Short-term investments 1,300,000 6,560,665 942,381 Amounts due from related parties (i) 1,018,963 2,360,267 339,031 Amounts due from Group companies ​ 565,101 ​ 3,337,273 ​ 479,369 Prepayments and other current assets 441,590 295,377 42,428 Total current assets 23,481,920 43,950,243 6,313,058 ​ Non-current assets ​ ​ ​ ​ ​ Property, equipment and software, net 16,578 27,719 3,982 Right-of-use assets — 452,883 65,053 Other non-current assets — 60,306 8,662 Total non-current assets 16,578 540,908 77,697 Total assets ​ 23,498,498 44,491,151 6,390,755 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ RMB RMB US$ LIABILITIES Current liabilities Amounts due to related parties (i) 458,147 1,502,892 215,877 Amounts due to Group companies 1,575,534 5,393,858 774,779 Customer advances and deferred revenues 190,382 605,969 87,042 Payable to merchants 17,275,934 29,657,227 4,259,994 Accrued expenses and other liabilities 1,500,951 3,420,728 491,358 Merchant deposits 4,188,273 7,840,912 1,126,277 Short-term borrowings ​ — ​ 898,748 ​ 129,097 Lease liabilities ​ — ​ 90,523 ​ 13,003 Total current liabilities ​ 25,189,221 ​ 49,410,857 ​ 7,097,427 Lease liabilities ​ — ​ 382,673 ​ 54,968 Total non-current liabilities — 382,673 54,968 Total liabilities 25,189,221 49,793,530 7,152,395 i) Information with respect to related parties is discussed in Note 19. 1. Organization (Continued) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ RMB RMB RMB US$ Net revenues from ​ ​ ​ ​ ​ ​ ​ ​ Group companies 207,570 ​ 298,415 2,244,429 322,392 External 1,744,076 ​ 10,136,874 17,630,903 2,532,521 Net revenues 1,951,646 ​ 10,435,289 19,875,332 2,854,913 Net loss (8,924) ​ (1,552,789) (3,611,656) (518,782) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ RMB RMB RMB US$ Net cash generated from operating activities 10,391,383 ​ 8,984,498 11,139,572 1,600,099 Net cash generated from /(used in) investing activities 88,404 ​ (1,147,101) (5,249,046) (753,978) Net cash provided by financing activities 200,000 ​ 507,767 4,546,481 653,061 Net increase in cash, cash equivalents and restricted cash 10,679,787 ​ 8,345,164 10,437,007 1,499,182 ​ There are no consolidated VIE’s assets that are pledged or collateralized for the VIE’s obligations and which can only be used to settle the VIE’s obligations, except for registered capital and the PRC statutory reserves. Relevant PRC laws and regulations restrict the VIE from transferring a portion of its net assets, equivalent to the balance of their statutory reserves and its share capital, to the Company in the form of loans and advances or cash dividends. Please refer to Note 21 for disclosure of the restricted net assets. As the VIE is incorporated as a limited liability company under the PRC Company Law, creditors of the VIE do not have recourse to the general credit of the Company for any of the liabilities of the VIE. There were no other pledges or collateralization of the VIE’s assets.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies (a) Basis of presentation The accompanying consolidated financial statements have been prepared in accordance with the accounting principles generally accepted in the United States of America (“US GAAP”). (b) Principles of consolidation The consolidated financial statements include the financial statements of the Company, its subsidiaries, the VIE and the subsidiaries of the VIE. All significant inter-company transactions and balances between the Company, its subsidiaries, the VIE and subsidiaries of the VIE have been eliminated upon consolidation. 2. Summary of Significant Accounting Policies (Continued) (c) Use of estimates The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the balance sheet dates and revenues and expenses during the reporting periods. Significant accounting estimates reflected in the Group’s consolidated financial statements include, but not limited to provision for prepayments made on behalf of merchants, economic lives and impairment of long-lived assets, valuation of short-term and long-term investments, valuation allowance for deferred tax assets, uncertain tax position, valuation for share-based compensation, liability component of convertible bonds and incremental borrowing rates for operating lease liabilities. Changes in facts and circumstances may result in revised estimates. Actual results could differ from those estimates, and as such, differences may be material to the consolidated financial statements. (d) Foreign currency The functional currency of the Company and its overseas subsidiaries is the US$. The Company’s PRC subsidiaries, the VIE and subsidiaries of the VIE determined their functional currencies to be RMB based on the criteria of ASC 830, Foreign Currency Transactions denominated in foreign currencies are re-measured into the functional currency at the exchange rates prevailing on the transaction dates. Monetary assets and liabilities denominated in foreign currencies are re-measured at the exchange rates prevailing at the balance sheet date. Non-monetary items that are measured in terms of historical cost in foreign currency are re-measured using the exchange rates at the dates of the initial transactions. Exchange gains and losses are included in the consolidated statements of comprehensive loss. The Company uses the average exchange rate for the year and the exchange rate at the balance sheet date to translate the operating results and financial position, respectively. Translation differences are recorded in accumulated other comprehensive income/(loss), a component of shareholders’ (deficits)/ equity. (e) Convenience translation Amounts in US$ are presented for the convenience of the reader and are translated at the noon buying rate of US$1.00 to RMB6.9618 on December 31, 2019, the last business day in December 2019, as published on the website of the United States Federal Reserve Board. No representation is made that the RMB amounts could have been, or could be, converted into US$ at such rate. (f) Cash and cash equivalents Cash and cash equivalents consist of cash on hand and highly liquid investments which are unrestricted as to withdrawal or use and have original maturities of three months or less when purchased. (g) Restricted cash Restricted cash mainly represents cash received from consumers and reserved in a bank supervised account for payments to merchants. 2. Summary of Significant Accounting Policies (Continued) (h) Short-term investments All highly liquid investments with original maturities of greater than three months but less than twelve months, are classified as short-term investments. Investments that are expected to be realized in cash during the next twelve months are also included in short-term investments. The Group accounts for short-term debt investments in accordance with ASC Topic 320 (“ASC 320”), Investments — Debt Securities Investments — Equity Securities . Short-term debt investments include time deposits and wealth management products in financial institutions that the Group has positive intent and ability to hold to maturity, both of which are categorized as “held to maturity”. Wealth management products with the intention to sell in the near term are classified as trading securities and measured at fair value. The Company also holds marketable equity securities in a listed company and measures it at fair value. Any realized gains or losses on the sale of the short-term investments are determined on a specific identification method and are reflected in earnings during the period in which gains or losses are realized. Realized and unrealized gains and losses and interest income from the short-term investments are recorded in “Interest and investment gain, net” in the consolidated statements of comprehensive loss. (i) Property, equipment and software, net Property, equipment and software are stated at cost and are depreciated and amortized using the straight-line method over the estimated useful lives of the assets, as follows: ​ ​ ​ ​ Category Estimated useful life Computer and office equipment 3 years Purchased software ​ 3 Leasehold improvements Over the shorter of lease terms or the estimated useful lives of the assets ​ Repair and maintenance costs are charged to expense as incurred, whereas the costs of renewals and betterments that extend the useful lives of property, equipment and software are capitalized as additions to the related assets. Retirements, sales and disposals of assets are recorded by removing the cost and accumulated depreciation from the asset and accumulated depreciation accounts with any resulting gain or loss reflected in the consolidated statements of comprehensive loss. Direct costs that are related to the construction of property, equipment and software and incurred in connection with bringing the assets to their intended use are capitalized as construction in progress. Construction in progress is transferred to specific property, equipment and software, and the depreciation of these assets commences when the assets are ready for their intended use. 2. Summary of Significant Accounting Policies (Continued) (j) Equity method investments The Group accounts for its investments in common stock or in-substance common stock in entities in which it can exercise significant influence but does not own a majority equity interest or control using the equity method of accounting in accordance with ASC Subtopics 323-10 ("ASC 323-10"), Investments-Equity Method and Joint Ventures: Overall (k) Impairment of long-lived assets other than goodwill The Group evaluates its long-lived assets, including fixed assets and intangible assets with finite lives, for impairment whenever events or changes in circumstances, such as a significant adverse change to market conditions that will impact the future use of the assets, indicate that the carrying amount of an asset may not be fully recoverable. When these events occur, the Group evaluates the recoverability of long-lived assets by comparing the carrying amounts of the assets to the future undiscounted cash flows expected to result from the use of the assets and their eventual disposition. If the sum of the expected undiscounted cash flows is less than the carrying amounts of the assets, the Group recognizes an impairment loss based on the excess of the carrying amounts of the assets over their fair value. Fair value is generally determined by discounting the cash flows expected to be generated by the assets, when the market prices are not readily available. For all periods presented, there were no impairment of any of the Group’s long-lived assets. (l) Fair value of financial instruments The Group’s financial instruments include cash and cash equivalents, restricted cash, receivables from payment platforms, amount due from/to related parties, prepayment made on behalf of merchants, merchant deposits, customer advances, payables to merchants, short-term investments and convertible bonds. For the aforementioned financial instruments included in current assets and liabilities, except for ones measured at fair value, their carrying amount approximated to their respective fair values because of the general short maturities. The fair value of convertible bonds that are not reported at fair value are disclosed in Note 14. The Group applies ASC 820, Fair Value Measurements and Disclosures ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 — Other inputs that are directly or indirectly observable in the marketplace. 2. Summary of Significant Accounting Policies (Continued) (l) Fair value of financial instruments (Continued) Level 3 — Unobservable inputs which are supported by little or no market activity. ASC 820 describes three main approaches to measuring the fair value of assets and liabilities: (1) market approach; (2) income approach; and (3) cost approach. The market approach uses prices and other relevant information generated from market transactions involving identical or comparable assets or liabilities. The income approach uses valuation techniques to convert future amounts to a single present value amount. The measurement is based on the value indicated by current market expectations about those future amounts. The cost approach is based on the amount that would currently be required to replace an asset. (m) Revenue recognition The Group through its platform primarily offers online marketplace services that enable third-party merchants to sell their products to consumers in China. Revenues from online marketplace services consist of online marketing services revenues and transaction services fees. Payments for services are generally received before deliveries. Effective January 1, 2018, the Group adopted ASU 2014-09, Revenue from contracts with Customers (Topic 606), The Group presents value added taxes (“VAT”) as reductions of revenues. Online marketplace services The Group charges fees for transaction services to merchants for sales transactions completed on the Group’s online marketplace, where the Group does not take control of the products provided by the merchants at any point in the time during the transactions and does not have latitude over pricing of the merchandise. Transaction services fee is determined as a percentage based on the value of merchandise being sold by the merchants. Revenues related to transaction services are recognized in consolidated statements of comprehensive loss at the time when the Group’s service obligations to the merchants are determined to have been completed under each sales transaction upon the consumers’ confirming the receipts of goods. Fees charged for transaction services are not refundable if and when consumers return the merchandise to merchants. The Group also entered into contractual agreements with certain merchants to provide online marketing services on the Group’s online marketplace for which the Group receives service fees from merchants. Online marketing services allow merchants to bid for keywords that match product listings appearing in search or browser results on the Group’s online marketplace. Merchants prepay for online marketing services that are charged on a cost-per-click basis. The Group provides the online marketing services on its own platforms without involvement of any other party. Under ASC 606, the related revenues are recognized at a point of time when consumers click the merchants’ product listings when services are completed by the Group for the merchants. The positioning of such listings and the price for such positioning are determined through an online auction system, which facilitates price discovery through a market-based mechanism. 2. Summary of Significant Accounting Policies (Continued) (m) Revenue recognition (Continued) The Group provides sales incentives to certain merchants that entitle them to receive price reduction on the online marketplace services by meeting certain requirements. The Group nets the sales incentives against online marketplace services revenues. In order to promote its online marketplace and attract more registered consumers, the Group at its own discretion offers various forms of incentives, for example, coupons, credits and discounts that are not specific to any merchant, to consumers that are not customers of the Group. Evaluation of the varying features of different incentive programs were made to determine that incentives offered to consumers are generally not considered as payments to customers. Such evaluation included the consideration of whether the incentives represent implicit obligation to consumers on behalf of merchants and if so, whether the consumers would be considered as customers of the Group. Coupons and credits redeemable for coupons can only be used for future purchases of eligible merchandise offered on the Group’s online marketplace to reduce purchase price. As the consumers are required to make future purchases of the merchants’ merchandise to redeem the coupons, the Group recognizes the amounts of redeemed coupons primarily as marketing expenses when future purchases are made. Discounts provided to consumers are recognized as marketing expenses when the related transaction services revenues are recognized. During the years ended December 31, 2018 and 2019, the Group also issued to consumers at its discretion, cash redeemable credits upon their completion of certain actions unrelated to the purchases of any specific merchant products on the Group’s online marketplace. As the credits were redeemable for cash, the Group accrued for the related costs in marketing expenses based on the cash redemption value of each credit as it is issued, assuming all credits will be redeemed. As of December 31, 2018 and 2019, the amount of outstanding credits were immaterial. (n) Costs of revenues Costs of online marketplace services consist primarily of payment processing fees paid to third party online payment platforms, costs associated with the operation of the Group’s platform, such as call center and merchant support costs, bandwidths and server costs, amortization, depreciation and maintenance costs, staff costs and share-based compensation expenses, surcharges and other expenses directly attributable to the online marketplace services. (o) Advertising expenditures Advertising expenditures are expensed when incurred and are included in sales and marketing expenses. Total amount of advertising expenditures and incentive programs recognized in sales and marketing expenses were RMB1,259,610, RMB12,867,833 and RMB25,867,772 (US$3,715,673) for the years ended December 31, 2017, 2018 and 2019, respectively. (p) Research and development expenses Research and development expenses include payroll, employee benefits, and other operating expenses associated with research and platform development. Research and development expenses also include rent, depreciation and other related expenses. To date, expenditures incurred between when the application has reached the development stage and when it is substantially complete and ready for its intended use have been inconsequential and, as a result, the Company did not capitalize any software development costs in the accompanying consolidated financial statements. 2. Summary of Significant Accounting Policies (Continued) (q) Leases The Group adopted ASU No. 2016-02, Leases (Topic 842) ("ASU 2016-02"), effective January 1, 2019 using the modified retrospective method and did not restate comparable periods. The Group elected the package of practical expedients permitted under the transition guidance, which allowed the Group to carry forward the historical lease classification for any expired or existing contract and the accounting for the initial direct costs on those leases on the adoption date. The Group also elected the practical expedient of the short-term lease exemption for contracts with lease terms of 12 months or less. The Group as the lessee determines if an arrangement is a lease at inception. Leases are classified as operating or finance leases in accordance with the recognition criteria in ASC 842-20-25. The Group's lease portfolio consisted entirely of operating leases as of January 1 and December 31, 2019. The Group's leases do not contain any residual value guarantees or material restrictive covenants. At the commencement date of an operating lease, the Group records a right-of-use ("ROU") asset and lease liability based on the present value of the lease payments over the lease term. Variable lease payments not dependent on an index or rate are excluded from the ROU asset and lease liability calculations and are recognized in expense in the period which the obligation for those payments is incurred. As the rate implicit in the Group's lease is not typically readily available, the Group uses an incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. This incremental borrowing rate reflects the fixed rate at which the Group could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. ROU assets include any lease prepayments and are reduced by lease incentives. Operating lease expense for lease payments is recognized on a straight-line basis over the lease term. Lease terms are based on the non-cancelable term of the lease and may contain options to extend the lease when it is reasonably certain that the Group will exercise that option. The cumulative effects of changes made to the Group's condensed consolidated balance sheet on January 1, 2019 for the adoption of ASU 2016-02 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ Balance at ​ ​ December ​ ​ ​ January 1, ​ ​ 31, 2018 ​ Adjustments ​ 2019 ​ RMB RMB RMB US$ Assets: Prepayments and other current assets 953,989 ​ (2,768) ​ 951,221 ​ 136,634 Right-of-use assets — ​ 221,521 ​ 221,521 ​ 31,820 Liabilities: ​ ​ ​ Current portion of lease liabilities — ​ 55,180 ​ 55,180 ​ 7,926 Non-current portion of lease liabilities — ​ 174,681 ​ 174,681 ​ 25,091 Accrued expenses and other liabilities 2,225,667 ​ (11,108) ​ 2,214,559 ​ 318,101 ​ As of January 1, 2019, the difference between the lease liabilities and right-of-use assets related to the reversal of existing deferred rent and prepaid rent balances is RMB11,108 (US$1,596) and RMB2,768 (US$398), respectively. The adoption of the standard did not impact the Company's consolidated statements of comprehensive loss and cash flows. 2. Summary of Significant Accounting Policies (Continued) (r) Income taxes The Group follows the liability method of accounting for income taxes in accordance with ASC 740 (‘‘ASC 740’’), Income Taxes. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial reporting and tax bases of assets and liabilities using enacted tax rates that will be in effect in the period in which the differences are expected to reverse. The Group records a valuation allowance to offset deferred tax assets if based on the weight of available evidence, it is more-likely-than-not that some portion, or all, of the deferred tax assets will not be realized. The effect on deferred taxes of a change in tax rate is recognized in tax expense in the period that includes the enactment date of the change in tax rate. The Group accounted for uncertainties in income taxes in accordance with ASC 740. Interest and penalties related to unrecognized tax benefit recognized in accordance with ASC 740 are classified in the consolidated statements of comprehensive loss as income tax expenses. ​ (s) Share-based compensation The Group applies ASC 718 (‘‘ASC 718’’), Compensation—Stock Compensation, to account for its employee share-based payments. In accordance with ASC 718, the Group determines whether an award should be classified and accounted for as a liability award or an equity award. All of the Group’s share-based awards to employees were classified as equity awards. The Group measures the employee share-based compensation based on the fair value of the award at the grant date. Expense is recognized using accelerated method over the requisite service period. The fair value of share options at the time of grant is determined using the binomial-lattice option pricing model. In accordance with ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvement to Employee Share-based Payment Accounting, the Group elected to account for forfeitures as they occurred. (t) Employee benefit expenses As stipulated by the regulations of the PRC, full-time employees of the Group are entitled to various government statutory employee benefit plans, including medical insurance, maternity insurance, workplace injury insurance, unemployment insurance and pension benefits through a PRC government-mandated multi-employer defined contribution plan. The Group is required to make contributions to the plan and accrues for these benefits based on certain percentages of the qualified employees’ salaries. (u) Comprehensive loss Comprehensive loss is defined as the changes in equity of the Group during a period from transactions and other events and circumstances excluding transactions resulting from investments by owners and distributions to owners. Among other disclosures, ASC 220, Comprehensive Income, requires that all items that are required to be recognized under current accounting standards as components of comprehensive income be reported in a financial statement that is displayed with the same prominence as other financial statements. For each of the periods presented, the Group’s comprehensive loss includes net loss and foreign currency translation difference and is presented in the consolidated statements of comprehensive loss. 2. Summary of Significant Accounting Policies (Continued) (v) Loss per share Basic loss per share is computed by dividing net loss attributable to ordinary shareholders by the weighted average number of ordinary shares outstanding during the period using the two-class method. Under the two-class method, net loss is allocated between ordinary shares and other participating securities based on their participating rights. Diluted loss per share is calculated by dividing net loss attributable to ordinary shareholders by the weighted average number of ordinary and dilutive ordinary equivalent shares outstanding during the period. Ordinary equivalent shares consist of shares issuable upon the exercise of share options and conversion of convertible bonds using the treasury stock method. Ordinary equivalent shares are not included in the denominator of the diluted loss per share calculation when inclusion of such shares would be anti-dilutive. Basic and diluted loss per share are not reported separately for Class A ordinary shares or Class B ordinary shares (the ''Ordinary Shares'') as each class of shares has the same rights to undistributed and distributed earnings. (w) Segment reporting The Group follows ASC 280, Segment Reporting. The Group’s Chief Executive Officer as the chief operating decision-maker reviews the consolidated financial results when making decisions about allocating resources and assessing the performance of the Group as a whole and hence, the Group has only one reportable segment. The Group operates and manages its business as a single segment. As the Group’s long-lived assets are substantially all located in the PRC and substantially all the Group revenues are derived from within the PRC, no geographical segments are presented. (x) Recent accounting pronouncements The Company ceased to be an emerging growth company since December 31, 2018. In June 2016, the FASB issued Accounting Standards Update ("ASU") 2016-13: Financial Instruments-Credit Losses (Topic 326) Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief and ASU 2019-11 Codification Improvements to Topic 326, Financial Instruments-Credit losses. In August 2018, the FASB issued ASU No. 2018-13 (‘‘ASU 2018-13’’), Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement In January 2020, the FASB issued ASU 2020-01, Investments-Equity Securities (Topic 321), Investments- Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)—Clarifying the Interactions between Topic 321, Topic 323, and Topic 815. This guidance addresses accounting for the transition into and out of the equity method and provides clarification of the interaction of rules for equity securities, the equity method of accounting, and forward contracts and purchase options on certain types of securities. This standard is effective for the Company beginning January 1, 2021 including interim periods within the fiscal year. Early adoption is permitted. The Company is still evaluating the impact on its consolidated financial statements. ​

Concentration of Risks

Concentration of Risks	12 Months Ended
	Dec. 31, 2019
Concentration of Risks
Concentration of Risks	3. Concentration of Risks (a) Concentration of credit risk Financial instruments that potentially subject the Group to significant concentration of credit risk consist primarily of cash and cash equivalents, restricted cash, receivables from online payment platforms, amounts due from related parties and short-term investments. As of December 31, 2018 and 2019, all of the Group’s cash and cash equivalents, restricted cash and short-term investments were held at reputable financial institutions with high-credit ratings. In the event of bankruptcy of one of these financial institutions, the Group may not be able to claim its cash and demand deposits back in full. The Group continues to monitor the financial strength of the financial institutions. There has been no recent history of default in relation to these financial institutions. Receivables from online payment platforms and amounts due from related parties (Note 19), unsecured and denominated in RMB and US$, derived from merchandise sales on the Group’s online marketplace to consumers, are exposed to credit risk. The risk is mitigated by credit evaluations the Group performs on the selected online payment platforms that are highly reputable and market leaders. There has been no default of payments from these online payment platforms. (b) Business, customer, political, social and economic risks The Group participates in a dynamic and competitive high technology industry and believes that changes in any of the following areas could have a material adverse effect on the Group’s future financial position, results of operations or cash flows: changes in the overall demand for services; changes in competitive landscape including potential new entrants; advances and new trends in new technology; strategic relationships or customer relationships; regulatory considerations; and risks associated with the Group’s ability to attract and retain employees necessary to support its growth. (i) Business supplier risk - there were no suppliers whose purchases individually represent greater than 10% of the total purchases of the Group for the years ended December 31, 2018 and 2019. (ii) Customer risk - there were no customers whose revenues individually represent greater than 10% of the total revenues of the Group for the years ended December 31, 2018 and 2019. (iii) Economic risk - the Group’s operations could be adversely affected by significant political, economic and social uncertainties in the PRC. Although the PRC government has been pursuing economic reform policies for more than 20 years, no assurance can be given that the PRC government will continue to pursue such policies or that such policies may not be significantly altered, especially in the event of a change in leadership, social or political disruption or unforeseen circumstances affecting the PRC political, economic and social conditions. There is also no guarantee that the PRC government’s pursuit of economic reforms will be consistent or effective. (c) Foreign currency exchange rate risk The Group is exposed to foreign currency exchange rate risk, which mainly affects the monetary assets denominated in the currencies other than the functional currencies of the respective entities. From July 21, 2005, the RMB is permitted to fluctuate within a narrow and managed band against a basket of certain foreign currencies. The (depreciation)/appreciation of the US$ against RMB was approximately (5.8)%, 5.0% and 1.6% for the years ended December 31, 2017, 2018 and 2019, respectively. The functional currency and the reporting currency of the Company are the US$ and the RMB, respectively. Most of the Group’s revenues and costs are denominated in RMB, while a portion of cash and cash equivalents and short-term investments, are denominated in US$. It is difficult to predict how market forces or PRC or U.S. government policy may impact the exchange rate between the RMB and the US$in the future. 3. Concentration of Risks (Continued) (d) Currency convertibility risk The Group transacts most of its business in RMB, which is not freely convertible into foreign currencies. On January 1, 1994, the PRC government abolished the dual rate system and introduced a single rate of exchange as quoted daily by the People’s Bank of China (the ''PBOC''). However, the unification of the exchange rates does not imply that the RMB may be readily convertible into US$ or other foreign currencies. All foreign exchange transactions continue to take place either through the PBOC or other banks authorized to buy and sell foreign currencies at the exchange rates quoted by the PBOC. Approval of foreign currency payments by the PBOC or other institutions requires submitting a payment application form together with suppliers’ invoices, shipping documents and signed contracts.

Short-term Investments

Short-term Investments	12 Months Ended
	Dec. 31, 2019
Short-term Investments
Short-term Investments	4. Short-term Investments Short-term investments classification as of December 31, 2018 and 2019 were shown as below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ 2019 ​ ​ RMB ​ RMB ​ US$ Debt securities: ​ ​ ​ ​ ​ ​ Held-to-maturity 7,630,689 34,481,053 4,952,893 Trading — 795,849 114,317 Equity securities: ​ ​ ​ ​ ​ ​ Marketable — 11,925 1,713 ​ 7,630,689 35,288,827 5,068,923 ​ The gross unrecognized holding gain or loss on the held-to-maturity debt securities was nil and nil as of December 31, 2018 and 2019, respectively. The cost of trading debt securities was nil and RMB795,849 (US$114,317), with gross unrealized gain or loss of nil and nil, as of December 31, 2018 and 2019, respectively. For the years ended December 31, 2017, 2018 and 2019, interest income related to debt securities was RMB12,483, RMB115,737 and RMB500,298 (US$71,863), respectively. As of December 31, 2018 and 2019, the cost of marketable equity securities was nil and RMB23,398 (US$3,361), respectively; and the unrealized loss included in the carrying amount was nil and RMB11,473 (US$1,648), respectively. For the years ended December 31, 2017, 2018 and 2019, the realized loss from the marketable equity securities was nil, nil and RMB5,435 (US$781), respectively.

Prepayments and Other Current A

Prepayments and Other Current Assets	12 Months Ended
	Dec. 31, 2019
Prepayments and Other Current Assets
Prepayments and Other Current Assets	5. Prepayments and Other Current Assets The components of prepayments and other current assets are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ 2019 ​ RMB RMB US$ Prepayments 667,113 645,169 92,673 Interest receivables 101,062 146,294 21,014 VAT recoverable 63,005 102,426 14,713 Rental and other deposits 64,902 12,060 1,732 Loan to a third party 35,000 — — Staff advances 7,868 4,020 577 Payments made on behalf of merchants 11,105 27,360 3,930 Provision for payments made on behalf of merchants ​ (3,249) ​ (15,032) ​ (2,159) Others 7,183 27,980 4,019 ​ 953,989 950,277 136,499 ​ The prepayments primarily consist of advertising fees paid in advance.

Property, Equipment and Softwar

Property, Equipment and Software, Net	12 Months Ended
	Dec. 31, 2019
Property, Equipment and Software, Net
Property, Equipment and Software, Net	6. Property, Equipment and Software, Net ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ US$ At cost: ​ ​ ​ ​ ​ ​ Computer, office equipment and purchased software ​ 27,148 49,129 7,057 Leasehold improvement ​ 10,654 ​ 18,826 ​ 2,704 ​ ​ 37,802 ​ 67,955 ​ 9,761 Less: accumulated depreciation ​ (8,727) (26,682) (3,833) ​ ​ 29,075 41,273 5,928 ​ For the years ended December 31, 2017, 2018 and 2019, the Group recorded depreciation expenses of RMB2,265, RMB5,934 and RMB18,098 (US$2,600), respectively, and were included in the following captions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Costs of revenues ​ 553 ​ 1,291 3,603 518 Sales and marketing expenses ​ 546 ​ 805 2,415 347 General and administrative expenses ​ 181 ​ 1,074 1,901 273 Research and development expenses ​ 985 ​ 2,764 10,179 1,462 ​ ​ 2,265 ​ 5,934 18,098 2,600 ​

Intangible Asset

Intangible Asset	12 Months Ended
	Dec. 31, 2019
Intangible Asset
Intangible Asset	7. Intangible Asset Intangible asset consisted of the following: ​ ​ ​ ​ ​ Total ​ ​ RMB Balance as of January 1, 2018 — Addition 2,852,370 Amortization (491,069) Foreign currency translation difference 218,037 Balance as of December 31, 2018 ​ 2,579,338 Amortization ​ (619,733) Foreign currency translation difference ​ 34,687 Balance as of December 31, 2019 1,994,292 ​ In February 2018, the Company entered into a strategic cooperation framework agreement (the “Agreement”) with an affiliate of Tencent Group. The Company and Tencent Group agreed to cooperate in a number of areas primarily for Tencent Group to provide the Company Weixin access point and other services and to pursue additional opportunities for future potential cooperation. The Agreement is valid for five years, from March 1, 2018 to February 28, 2023. The Company recognized the Agreement as an intangible asset at the fair value of consideration paid in the form of convertible preferred shares of RMB2,852 million. The Group recognizes the related amortization expense in costs of revenues, over the period of five years using the straight-line method. Amortization expense for intangible asset were RMB491,069 and RMB619,733 (US$89,019) for the years ended December 31, 2018 and 2019, respectively. No impairment charge was recognized on the intangible asset for the years ended December 31, 2018 and 2019. The estimated annual amortization expense for each of the remaining fiscal years is as follows: ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ RMB ​ US$ 2020 629,233 90,384 2021 627,514 90,137 2022 627,514 90,137 2023 110,031 15,805 ​

Leases

Leases ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Leases
Leases	8. Leases The Group has operating leases mainly for offices in China. For the year ended December 31, 2019, operating lease costs and short-term lease costs were RMB94,929 and RMB34,255, respectively. There were no leasing costs other than the operating lease costs and short-term lease costs for the year ended December 31, 2019. A maturity analysis of the Company's operating lease liabilities and reconciliation of the undiscounted cash flows to the operating lease liabilities recognized on the condensed consolidated balance sheet was as below: ​ ​ ​ ​ ​ ​ ​ ​ Rental ​ ​ RMB ​ US$ ​ ​ ​ ​ ​ 2020 142,058 20,405 2021 150,231 21,579 2022 128,731 18,491 2023 94,598 13,588 2024 and after 97,558 14,013 Total undiscounted cash flows 613,176 88,076 Less: imputed interest (68,849) (9,888) Present value of lease liabilities 544,327 78,188 ​ As of December 31, 2019, the Company had no operating leases that had not yet commenced. The weighted average remaining lease terms of the right-of-use assets was 4.37 years. A weighted average incremental borrowing rate of 5.36% was adopted on the commencement date in determining the present value of lease payments. Other supplemental information related to leases is summarized below: ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2019 ​ 2019 ​ RMB US$ ​ ​ ​ ​ ​ Operating cash flows for operating leases 76,130 10,935 ROU assets obtained in exchange for new operating lease liabilities 402,646 57,836 ​	8. Leases The Group has operating leases mainly for offices in China. For the year ended December 31, 2019, operating lease costs and short-term lease costs were RMB94,929 and RMB34,255, respectively. There were no leasing costs other than the operating lease costs and short-term lease costs for the year ended December 31, 2019. A maturity analysis of the Company's operating lease liabilities and reconciliation of the undiscounted cash flows to the operating lease liabilities recognized on the condensed consolidated balance sheet was as below: ​ ​ ​ ​ ​ ​ ​ ​ Rental ​ ​ RMB ​ US$ ​ ​ ​ ​ ​ 2020 142,058 20,405 2021 150,231 21,579 2022 128,731 18,491 2023 94,598 13,588 2024 and after 97,558 14,013 Total undiscounted cash flows 613,176 88,076 Less: imputed interest (68,849) (9,888) Present value of lease liabilities 544,327 78,188 ​ As of December 31, 2019, the Company had no operating leases that had not yet commenced. The weighted average remaining lease terms of the right-of-use assets was 4.37 years. A weighted average incremental borrowing rate of 5.36% was adopted on the commencement date in determining the present value of lease payments. Other supplemental information related to leases is summarized below: ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2019 ​ 2019 ​ RMB US$ ​ ​ ​ ​ ​ Operating cash flows for operating leases 76,130 10,935 ROU assets obtained in exchange for new operating lease liabilities 402,646 57,836 ​
Provision For Prepayments Made On Behalf Of Merchants	$ 1,692	¥ 11,782	¥ 2,155

Other Non-Current Asset

Other Non-Current Asset	12 Months Ended
	Dec. 31, 2019
Other Non-current Assets
Other Non-current Assets	9. Other Non-current Assets Equity method investments are included in other non-current assets on the Company's consolidated balance sheets. Equity method investments consist of the Company's investments as a limited partner in certain limited partnership funds, including funds set up by the Company's related parties, to make strategic investments. As of December 31, 2018, The Company made advances in total of RMB 182,667 to set up the funds. As of December 31, 2019, the carrying amount for the investments was RMB 433,649 (US$ 62,290 ). No equity method investments were considered, individually or in aggregate, material as of December 31, 2019. During the year ended December 31, 2019, the Group shared the profits or losses of the equity investees and recognized RMB 28,676 (US$ 4,119 ) in share of results of equity investees in the consolidated statements of comprehensive loss. There was no impairment on these investments during the year ended December 31, 2019.

Accrued Expenses and Other Liab

Accrued Expenses and Other Liabilities	12 Months Ended
	Dec. 31, 2019
Accrued Expenses and Other Liabilities
Accrued Expenses and Other Liabilities	10. Accrued Expenses and Other Liabilities The components of accrued expenses and other liabilities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ US$ Payroll payable 389,615 1,061,228 152,436 Accrued expenses 1,371,483 2,727,273 391,748 VAT and other tax payable 436,495 1,045,796 150,219 Others 28,074 42,765 6,144 ​ 2,225,667 4,877,062 700,547 ​ Accrued expenses primarily consisted of accrued advertising and marketing expenses.

Short-term Borrowings

Short-term Borrowings	12 Months Ended
	Dec. 31, 2019
Short-term Borrowings
Short-term Borrowings	11. Short-term Borrowings ​ As of December 31, 2019, the Group obtained short-term borrowings from banks of RMB897,022 in aggregate collateralized by bank wealth management products of RMB923,800, which were classified as short-term investments as provided by one of the Group's wholly-owned subsidiaries. The annual interest rates of these borrowings are approximately 2.70% to 3.00%. For the year ended December 31,2019,the Group recognized interest expense of RMB1,726 (US$248) in the consolidated statements of comprehensive loss. ​

Convertible Bonds

Convertible Bonds	12 Months Ended
	Dec. 31, 2019
Convertible Bonds
Convertible Bonds	12. Convertible Bonds On September 27, 2019, the Company issued US$1,000,000 principal amount 0.00% convertible senior notes including US$125,000 sold upon the exercise of the over-allotment option (the "Notes"). The Notes will mature on October 1, 2024 unless redeemed, repurchased or converted prior to such date. Holders may convert their Notes at their option prior to the close of business on the business day immediately preceding April 1, 2024 only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2019 (and only during such calendar quarter), if the last reported sale price of American Depositary Shares (''ADSs''), each representing four Class A ordinary shares of the Company, par value US$0.000005 per share, for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any ten consecutive trading day period in which the trading price per US$1,000 principal amount of the Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the ADSs and the conversion rate on each such trading day; (3) if the Company calls the Notes for a tax redemption; (4) if the Company calls the Notes for redemption at its option or (5) upon the occurrence of specified corporate events. On or after April 1, 2024 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their Notes at any time. Upon conversion, the Company will pay or deliver, as the case may be, cash, ADSs, or a combination of cash and ADSs, at its election. 12. Convertible Bonds (Continued) The initial conversion rate of the Notes is 23.4680 of the Company's ADS per US$1,000 principal amount of the Notes (which is equivalent to an initial conversion price of approximately US$42.61 per ADS). The conversion rate will be subject to adjustment in some events. In addition, following certain corporate events that occur prior to the maturity date, if a make-whole fundamental change occurs prior to the maturity date of the Notes, or under certain circumstances upon a tax redemption or the Company's optional redemption, the Company will, in certain circumstances, increase the conversion rate for a holder who elects to convert its Notes in connection with such corporate event, such make-whole fundamental change or such notice of tax redemption or notice of optional redemption, as the case may be. Upon conversion, the Company will pay or deliver, as the case may be, cash, ADSs (plus cash in lieu of a fractional ADS) or a combination of cash and ADSs, at its election. If the Company satisfies its conversion obligation solely in cash or through payment and delivery, as the case may be, of a combination of cash and ADSs, the amount of cash and ADSs, if any, due upon conversion will be based on a daily conversion value calculated on a proportionate basis for each trading day in a 40 trading day observation period. The Company may not redeem the Notes prior to October 1, 2022 unless certain tax-related events occur. On or after October 1, 2022, the Company may redeem for cash all or part of the Notes, at its option, if the last reported sale price of the Company's American Depositary Shares (the "ADSs") has been at least 130% of the conversion price then in effect on (i) each of at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the trading day immediately prior to the date the Company provides notice of redemption; and (ii) the trading day immediately preceding the date the Company sends such notice. Holders of the Notes may require the Company to repurchase all or part of their Notes in cash on October 1, 2022 or in the event of certain fundamental changes. No sinking fund is provided for the Notes. As the conversion option may be settled in cash, ADSs, or a combination of cash and ADSs at the Company’s option, the Company separated the Notes into liability and equity components in accordance with ASC 470-20, Debt with Conversion and Other Options. The carrying amount of the liability component was calculated by measuring the fair value of a similar liability that does not have an associated conversion feature. The carrying amount of the equity component representing the conversion option was determined by deducting the fair value of the liability component from the initial proceeds and recorded as additional paid-in capital. The resulting discount , together with the allocated issuance costs as mentioned below, are accreted at an effective interest rate of 11.15% over the period from the issuance date to October 1, 2022, the earliest put date of the Notes. The Group made estimates and judgments in determining the effective interest rate of the liability component of the Notes with assistance from an independent valuation firm. The gross proceeds from the issuance of the Notes were US$1,000,000. Debt issuance costs including underwriting commissions and offering expenses were approximately US$15,680, which were allocated to the liability and equity components proportionately. As of December 31, 2019, the principal amount of the liability component was US$1,000,000, unamortized debt discount was US$253,651, and net carrying amount of the liability component was RMB5,206,682. The carrying amount of the equity component was US$258,429. For the year ended December 31, 2019, the amount of interest cost recognized relating to the amortization of the discount on the liability component was RMB144,132 (US$20,703). The liability component will be accreted up to the principal amount over a remaining period of 2.75 years.

Convertible Preferred Shares

Convertible Preferred Shares	12 Months Ended
	Dec. 31, 2019
Convertible Preferred Shares
Convertible Preferred Shares	13. Convertible Preferred Shares The following table summarizes the issuances of convertible preferred shares (collectively, “Convertible Preferred Shares”): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Original Issuance ​ ​ ​ ​ ​ ​ Price per ​ Number of Name Issuance Date Share* Shares* Series A1 Convertible Preferred Shares ​ June 2015 ​ $ 0.0093 ​ 71,849,380 Series A2 Convertible Preferred Shares June 2015 ​ $ 0.0336 238,419,800 Series B1 Convertible Preferred Shares November 2015 ​ $ 0.1576 211,588,720 Series B2 Convertible Preferred Shares January 2016 ​ $ 0.1576 27,781,280 Series B3 Convertible Preferred Shares March 2016 ​ $ 0.1576 145,978,540 Series B4 Convertible Preferred Shares June 2016 ​ $ 0.1710 292,414,780 Series C1 Convertible Preferred Shares February 2017 ​ $ 0.3545 56,430,180 Series C2 Convertible Preferred Shares February 2017 ​ $ 0.3985 238,260,780 Series C3 Convertible Preferred Shares June 2017 ​ $ 0.4139 241,604,260 Series D Convertible Preferred Shares ​ March 2018** ​ $ 2.4832 ​ 551,174,340 * In connection with the issuance of Series D convertible preferred shares, the Company effected a change of authorized share capital (Note15), the Company’s then issued and outstanding Convertible Preferred Shares were split on a 1-to- 20 basis. The number of shares and per-share price in the consolidated financial statements were recasted on a retroactive basis to reflect the effect of these changes. ** Series D Convertible Preferred Shares were issued and converted in 2018. Therefore, the balance was nil as of December 31, 2018. The significant terms of the Convertible Preferred Shares are summarized as follows: Conversion Convertible Preferred Shares can be converted into Class A ordinary shares at the option of the holder at any time by dividing the applicable original purchase price by the applicable conversion price which is initially equal to the original purchase price and as such, the initial conversion ratio for each Convertible Preferred Share into each Ordinary Share shall be one-for-one. Convertible Preferred Shares shall automatically be converted into Class A ordinary shares at the then-effective conversion rate applicable to the relevant series of Convertible Preferred Shares upon the closing of an underwritten public offering of the Ordinary Shares of the Company in the United States. The conversion price is subject to additional adjustments if the Company makes certain dilutive issuances of shares. 13. Convertible Preferred Shares (Continued) Dividends The holders of outstanding shares of the Company shall be entitled to receive dividends, out of any assets legally available therefor, payable in US$ and annually when, as and if declared by the Board. Such distributions shall not be cumulative. Holders of the Convertible Preferred Shares shall also be entitled to receive any non-cash dividends declared by the Board on an as-converted basis. The dividends or distributions shall be distributed among all holders of Ordinary Shares and Convertible Preferred Shares in proportion to the number of Ordinary Shares that would be held by each such holder if all Convertible Preferred Shares had been converted to Ordinary Shares as of the record date fixed for determining those entitled to receive such distribution. Liquidation preference In the event of any liquidation, dissolution or winding up of the Company, either voluntary or involuntary, distributions to the shareholders of the Group shall be made as stated below: For the holders of teach series of Convertible Preferred Shares, (i) 100% of its issue price, plus (ii) an amount accruing there on at a compound annual rate of 8% of the 100% issue price beginning on its closing date, plus (iii) all declared but unpaid dividends thereon (Collectively, the ‘‘Preference Amount’’). If the Company has insufficient assets to permit payment of the Series D Preferred Share Preference Amount in full to all holders of the then issued and outstanding Series D Preferred Shares, then the assets of the Company shall be distributed ratably to the holders of the then issued and outstanding Series D Preferred Shares in proportion to the full Series D Preferred Share Preference Amount that each such holder of the then issued and outstanding Series D Preferred Shares would otherwise be entitled to receive hereunder. After the full Series D Preferred Share Preference Amount has been paid, any remaining funds or assets of the Company legally available for distribution to shareholders shall then be distributed to holders of Series C-3 Preferred Shares and Series C-2 Preferred Shares according to the sum of the Series C-3 Preferred Share Preference Amount and Series C-2 Preferred Share Preference Amount. If the Company has insufficient assets to permit payment of the Series C3 Preference Amount and the Series C2 Preference Amount in full to all holders of the then issued and outstanding holders of Series C3 Convertible Preferred Shares and Series C2 Convertible Preferred Shares, then the assets of the Company shall be distributed ratably to the holders of the then issued and outstanding Series C3 Convertible Preferred Shares and Series C2 in proportion to the full Series C3 Preference Amount and Series C2 Preference Amount that each such holder of the then issued and outstanding Series C3 Convertible Preferred Shares and Series C2 Convertible Preferred Shares would otherwise be entitled to receive hereunder. After the full Series C3 Preference Amount and the full Series C2 Preference Amount has been paid, any remaining funds or assets of the Company legally available for distribution to shareholders shall then be distributed to holders of Series C1 Convertible Preferred Shares and Series B Convertible Preferred Shares (including Series B1 to B4 Convertible Preferred Shares) according to the sum of the Series C1 Preference Amount and Series B Preference Amount. If the Company has insufficient assets to permit payment of the Series C1 Preference Amount and Series B Preference Amount in full to all holders of the then issued and outstanding holders of Series C1 Convertible Preferred Shares and Series B Convertible Preferred Shares, then the assets of the Company shall be distributed ratably to the holders of the then issued and outstanding Series C1 Convertible Preferred Shares and Series B Convertible Preferred Shares in proportion to the full Series C1 Convertible Preferred Share Preference Amount and Series B Convertible Preferred Share Preference Amount that each such holder of the then issued and outstanding Series C1 Convertible Preferred Shares and Series B Convertible Preferred Shares would otherwise be entitled to receive hereunder. 13. Convertible Preferred Shares (Continued) Liquidation preference(Continue) After the full Series C1 Preference Amount and the full Series B Preference Amount has been paid, any remaining funds or assets of the Company legally available for distribution to shareholders shall then be distributed to holders of Series A Convertible Preferred Shares (including Series A-1 and A2 Convertible Preferred Shares) according to the Series A Preference Amount. If the Company has insufficient assets to permit payment of the Series A Preference Amount in full to all holders of the then issued and outstanding holders of Series A Convertible Preferred Shares, then the assets of the Company shall be distributed ratably to the holders of the then issued and outstanding Series A Convertible Preferred Shares in proportion to the full Series A Preference Amount that each such holder of the then issued and outstanding Series A Convertible Preferred Shares would otherwise be entitled to receive hereunder. After the full Preference Amount on all outstanding Convertible Preferred Shares have been paid, any remaining funds or assets of the Company legally available for distribution to shareholders shall be distributed on a pro rata, pari passu basis among the holders of the Convertible Preferred Shares (calculated on an as-converted and fully-diluted basis), together with the holders of the Ordinary Shares. Deemed liquidation Any sale of shares, merger, consolidation or other similar transaction involving the Company in which its shareholders do not retain a majority of the voting power in the surviving or resulting entity, or a sale of all or substantially all the Company’s assets (the ‘‘Liquidation Event’’, for avoidance of doubt, each transaction under the acquisitions also referred herein as a Liquidation Event), shall be deemed a liquidation, dissolution or winding up of the Company, such that the liquidation preference shall apply as if all consideration received by the Company and its shareholders in connection with such event were being distributed in a liquidation of the Company (‘‘Deemed Liquidation’’). The Convertible Preferred Shares are not redeemable except in the event of Deemed Liquidation, which permits the holders to receive the Preference Amount as defined above. Voting Each Convertible Preferred Share shall carry a number of votes equal to the number of Class A ordinary shares then issuable upon its conversion into Class A ordinary shares at the record date for determination of the shareholders entitled to vote on such matters, or, if no such record date is established, at the date such vote is taken or any written consent of shareholders is solicited. Accounting for Convertible Preferred Shares In February 2016, all shareholders of the Company approved the declaration and payment of a special cash dividend in the amount of RMB18,326 to a shareholder of the Series B2 Convertible Preferred Shares. The dividend was recorded in accumulated deficits. In connection with the issuances of Series B1 Convertible Preferred Shares and Series B4 Convertible Preferred Shares, liquidation preferences of certain Convertible Preferred Shares were modified and deemed distribution of RMB12,104, nil and nil were recognized for the years ended December 31, 2016, 2017 and 2018, respectively. 13. Convertible Preferred Shares (Continued) Accounting for Convertible Preferred Shares (Continued) Concurrently with the issuance of Series C1 Convertible Preferred Shares in February 2017, the Company repurchased from a company controlled by the Founder and cancelled 56,430,180 of Class B ordinary shares for cash consideration of RMB137,580. The difference between the then fair value of the Class B ordinary shares of RMB32,677 and par value was recorded in accumulated deficits. The excess of consideration over the then fair value of the Ordinary Shares of RMB103,125 was accounted for as compensation expense within general and administrative expenses (Note 17). The excess of the issuance price paid by the investor over the then fair value of the Series C1 Convertible Preferred Shares of RMB26,413 was accounted for as a contribution from shareholder. In March 2018, the Company issued 551,174,340 Series D convertible preferred shares to existing shareholders and their affiliates including Tencent Group for a cash consideration of US$918,670 and an intangible asset at fair value (Note 7). In connection with the issuances of Series D convertible preferred shares, the liquidation preferences of Convertible Preferred Shares were amended. The amendment to the liquidation preference of the Convertible Preferred Shares was accounted for as modification as the fair value of Convertible Preferred Share immediately after the amendment was not significantly different from its fair value immediately before the amendment. The Company accounted for the modification that resulted in an increase to the fair value of the modified Convertible Preferred Shares of RMB80,496 (US$11,708) as deemed dividends during the year ended December 31, 2018. The Series A convertible preferred shares, the Series B convertible preferred shares, the Series C convertible preferred shares and the Series D convertible preferred shares (collectively the “Convertible Preferred Shares”) were classified as mezzanine equity as they were contingently redeemable upon the occurrence of a Deemed Liquidation event. The initial carrying amounts of the Convertible Preferred Shares were the fair value at the time of closing, less issuance costs. The Company did not accrete the Convertible Preferred Shares to liquidation value as a Deemed Liquidation event was not considered probable as of the end of each period presented. The Company determined conversion options embedded in the Convertible Preferred Shares did not require bifurcation because the underlying Class A ordinary shares were not publicly traded nor readily convertible into cash. There were no other embedded derivatives that required bifurcation. The Company also determined that there were no beneficial conversion features to be recorded. Upon completion of the IPO in July 2018, all of the convertible preferred shares were converted to 1,971,811,320 Class A ordinary shares and 103,690,740 Class B ordinary shares.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements
Fair Value Measurements	14. Fair Value Measurement In accordance with ASC 820, the Company measures the marketable equity securities with readily determinable fair value and certain wealth management products classified as trading securities on a recurring basis. The fair value of the marketable equity securities is measured using quoted market price and the fair value of certain wealth management products classified as trading securities is determined based on quoted prices of similar assets. 14. Fair Value Measurement (Continued) The following tables set forth the financial instruments measured at fair value on a recurring basis by level within the fair value hierarchy: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ Quoted Price in ​ Significant ​ ​ ​ ​ Active Market ​ Other ​ Unobservable ​ ​ for Identical Observable Inputs ​ ​ Assets (Level 1) Inputs (Level 2) ​ (Level 3) ​ RMB RMB RMB Recurring ​ As of December 31, 2019: ​ ​ ​ ​ ​ ​ Short-term investments: ​ ​ ​ ​ ​ ​ Debt securities: ​ ​ ​ ​ ​ ​ Trading ​ — ​ 795,849 ​ — Equity securities: ​ ​ ​ ​ ​ ​ Marketable ​ 11,925 ​ — ​ — ​ ​ 11,925 795,849 — ​ As of December 31, 2018 and 2019, the Group did not have any assets or liabilities that were measured at fair value on a non-recurring basis and no impairment charge was recorded. ​ The followings are financial instruments not measured at fair value in the consolidated balance sheets, but for which the fair value is estimated for disclosure purposes. The fair values of held-to-maturity debt investments are estimated using prevailing interest rates. The fair values of the convertible bonds are based on broker quotes. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ Quoted Price in ​ Significant ​ ​ ​ ​ Active Market ​ Other ​ Unobservable ​ ​ for Identical ​ Observable ​ Inputs ​ ​ Assets (Level 1) ​ Inputs (Level 2) ​ (Level 3) ​ RMB RMB RMB As of December 31, 2018: ​ ​ ​ ​ ​ Short term investments: ​ ​ ​ ​ ​ Debt securities: ​ ​ ​ ​ ​ ​ Held-to-maturity ​ — ​ 7,630,689 — As of December 31, 2019: ​ ​ ​ ​ ​ Short-term investments: ​ ​ ​ ​ ​ ​ Debt securities: ​ ​ ​ ​ ​ ​ Held-to-maturity ​ — ​ 34,481,053 — Convertible bonds ​ — ​ 8,037,280 — ​

Ordinary Shares

Ordinary Shares	12 Months Ended
	Dec. 31, 2019
Ordinary Shares
Ordinary Shares	15. Ordinary Shares Holders of Class A ordinary shares and Class B ordinary shares are entitled to the same rights except for voting rights. In respect of matters requiring a shareholder’s vote, each Class A ordinary share is entitled to one vote and each Class B ordinary share is entitled to ten votes. In connection with the issuance of Series D convertible preferred shares, the Company effected a change of authorized share capital by repurchasing all of the then issued and outstanding ordinary shares at par value and reissued 42,486,360 Class A ordinary shares and 1,716,283,460 Class B ordinary shares to its existing holders of ordinary shares. The number of shares and per-share price in the consolidated financial statements were recasted on a retroactive basis to reflect the effect of these changes. 15. Ordinary Shares (Continued) In the third quarter of 2018, the Company completed its Initial Public Offering (“IPO”) on the National Association of Securities Deal Automated Quotations under the symbol of “PDD” of 91,735,827 ADSs (including 6,135,827 ADSs sold upon the exercise of the underwriters’ over-allotment option), representing 366,943,308 Class A ordinary shares for a total proceeds net of issuance costs of US$1,690,696. Upon completion of the IPO, all convertible preferred shares were converted into ordinary shares. In February 2019, the Company completed a follow-on public offering and issued 48,435,000 ADSs, representing 193,740,000 Class A ordinary shares for total proceeds net of issuance costs of US$1,181,209.

Revenues

Revenues	12 Months Ended
	Dec. 31, 2019
Revenues
Revenues	16. Revenues ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 2018 2019 ​ 2019 ​ RMB ​ RMB RMB US$ Online marketplace services ​ ​ ​ ​ ​ ​ ​ ​ Online marketing services 1,209,275 ​ 11,515,575 26,813,641 3,851,539 Transaction services 531,416 ​ 1,604,415 3,328,245 478,072 Merchandise sales 3,385 ​ — — — ​ 1,744,076 ​ 13,119,990 30,141,886 4,329,611 ​ Contract balances ​ The Group’s contract liabilities comprised of customer advances, deferred revenues and portions of payable to merchants: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, 2018 ​ December 31, 2019 ​ December 31, 2019 ​ RMB RMB US$ Customer advances and deferred revenues 191,482 605,970 87,042 Payable to merchants 72,939 ​ 116,557 ​ 16,742 ​ Customer advances and deferred revenues and payable to merchants relate to considerations received in advance for online marketing services and transaction services, for which control of the services occur at a later point in time. The increase in the balance of contract liabilities was in line with the growth in online marketing services revenues and higher value of orders placed by consumers for which the related transaction services have not been completed. During the year ended December 31, 2019, revenues of RMB219,017 were recognized from the carrying value of contract liabilities as of December 31, 2018. During the year ended December 31, 2018, revenues of RMB83,639 were recognized from the carrying value of contract liabilities as of December 31, 2017.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2019
Share-Based Compensation
Share-Based Compensation	17. Share-Based Compensation In order to provide additional incentives to employees and to promote the success of the Group’s business, the Group adopted a share incentive plan in 2015 (the ''2015 Plan''). The 2015 Plan allows the Group to grant options to employees, directors, or consultants. Under the 2015 Plan, the maximum aggregate number of shares that may be issued shall not exceed 581,972,860. The terms of the options shall not exceed ten years from the date of grant. 17. Share-Based Compensation (Continued) In July 2018, the Group adopted the 2018 Share Incentive Plan (the “2018 Plan”). The 2018 Plan allows the Group to grant options and restricted share units (“RSUs”) to employees, directors or consultants. Under the 2018 Plan, the maximum aggregate number of shares that may be issued pursuant to all awards is initially 363,130,400, plus an annual increase on the first day of each fiscal year of the company during the term of the 2018 Plan commencing with the fiscal year beginning January 1, 2019, by an amount equal to the lessor of (i) 1.0% of the total number of shares issued and outstanding on the last day of the immediately preceding fiscal year, and (ii) such number of shares as may be determined by our board of directors. For the share options granted under the 2015 Plan and the 2018 Plan, in addition to the explicit service periods of four years, with 25% of the options vesting annually, Class A ordinary shares acquired from the exercise of vested options cannot be sold or transferred by the employees without the prior written consents of the Company within the first three years of vested (''Restricted Shares''). In the event that employment relationship is terminated with the Company, voluntarily or involuntarily, within the three-year lock-up periods, the Company may, at its sole discretion, repurchase the Restricted Shares at the employee’s exercise price. The Group determined the substance of the lock up periods to be additional implicit service periods of three years, thereby extending the vesting terms of the options to be seven years in total. The RSUs granted under the 2018 Plan vest over a period of four years with 25% vesting on each anniversary from the date of grant, or with 50% of the RSUs vesting on the second anniversary and 25% on each of the third and fourth anniversary from the date of grant. (a) The following table summarize the Group’s option activities under the 2015 Plan and the 2018 Plan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Weighted ​ average ​ ​ ​ average ​ ​ ​ ​ average ​ grant ​ Aggregate ​ remaining ​ ​ Number of ​ exercise ​ date fair ​ intrinsic ​ contractual ​ share options price value value term ​ ​ ​ US$ US$ US$ ​ Years Outstanding as of January 1,2017 ​ 203,733,060 0.0065 0.0301 ​ 10,390 ​ 9.25 Granted ​ 78,560,000 0.0065 0.1736 ​ ​ Forfeited ​ (9,850,200) 0.0065 0.0544 ​ ​ Outstanding as of December 31, 2017 ​ 272,442,860 ​ 0.0065 ​ 0.0706 ​ 144,258 ​ 8.57 Granted 359,390,000 0.0065 3.6289 ​ ​ Forfeited ​ (2,240,000) 0.0065 2.5006 ​ ​ ​ ​ Outstanding as of December 31, 2018 629,592,860 0.0065 2.0931 3,527,924 8.64 Granted 76,665,380 0.0065 7.7632 ​ ​ Forfeited (7,937,140) 0.0065 5.7059 ​ ​ Outstanding as of December 31, 2019 698,321,100 0.0065 2.6745 6,598,087 7.83 Vested and expected to vest as of December 31, 2019 698,321,100 0.0065 2.6745 6,598,087 7.83 Exercisable as of December 31,2019 298,464,265 0.0065 1.1083 2,820,040 7.01 ​ The aggregate intrinsic value is calculated as the difference between the exercise price of the awards and the fair value of the underlying Ordinary Shares at each reporting date, for those awards that had exercise price below the estimated fair value of the relevant Ordinary Shares. 17. Share-Based Compensation (Continued) (a) The total fair value of vested options was RMB13,525, RMB45,979 and RMB2,243,028 (US$322,191) for the years ended December 31, 2017, 2018 and 2019, respectively. As of December 31, 2019, total unrecognized share-based compensation expense relating to unvested awards was RMB9,994,423 (US$1,435,609) which is expected to be recognized over a weighted-average period of 4.83 years. The Group calculated the estimated fair value of the options on the respective grant dates using the binomial-lattice option valuation model with the following assumptions for each applicable period which took into account variables such as volatility, dividend yield, and risk-free interest rates: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 2018 2019 Risk-free interest rates ​ 2.26%-2.57% ​ 2.97%-3.13% ​ 1.50%-2.90% Expected volatility ​ 48.08%-49.35% ​ 46.23%-48.63% ​ 43.52%-57.59% Expected dividend yield ​ 0% ​ 0% ​ 0% Exercise multiple ​ 2.80 ​ 2.80 2.80 Post-vesting forfeit rate ​ 0% ​ 0% ​ 0% Fair value of underlying Ordinary Shares ​ $0.0858-$0.5359 ​ $1.5146-$5.7400 ​ $4.8550-$8.9875 Fair value of share option ​ $0.0808-$0.5302 ​ $1.5091-$5.7335 ​ $4.8485-$8.9810 ​ (b) The following table summarize the Group’s RSU activities under the 2018 Plan: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ average ​ ​ Number ​ grant date ​ ​ of RSUs ​ fair value ​ ​ ​ ​ US$ Outstanding as of January 1, 2018 — — Granted 8,295,240 6.2519 Outstanding as of December 31, 2018 ​ 8,295,240 ​ 6.2519 Granted ​ 36,409,188 ​ 6.7698 Vested ​ (567,636) ​ 6.9225 Forfeited ​ (2,761,724) ​ 6.4514 Outstanding as of December 31, 2019 41,375,068 6.6855 ​ The total fair value of the RSUs vested during the years ended December 31, 2018 and 2019 was nil and RMB As of December 31, 2019, RMB1,451,466 (US$208,490) of unrecognized share-based compensation expenses related to RSUs is expected to be recognized over a weighted average vesting period of 3.35 years using the accelerated method. Total unrecognized share-based compensation expenses may be adjusted for future changes when actual forfeitures incurred. 17. Share-Based Compensation (Continued) (c) The Group recognized share-based compensation expenses for the years ended December 31, 2017, 2018 and 2019 as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended ​ ​ December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ 2019 ​ RMB ​ RMB RMB US$ Costs of revenues ​ 796 ​ 3,488 ​ 23,835 3,424 Sales and marketing expenses ​ 1,675 ​ 405,805 ​ 860,862 123,655 General and administrative expenses i) / ii) ​ 108,141 ​ 6,296,186 ​ 786,641 112,994 Research and development ​ 5,893 ​ 136,094 ​ 886,368 127,319 ​ ​ 116,505 ​ 6,841,573 ​ 2,557,706 367,392 i) For the year ended December 31, 2017, the Company recorded RMB103,125, in share-based compensation expenses in connection with the repurchase of Class B ordinary shares from the Founder. No such transaction took place during the years ended December 31, 2018 and 2019. ii) In April 2018, the Company issued 254,473,500 Class A ordinary shares to a company controlled by the Founder at the par value of US$0.000005 per share pursuant to a shareholders’ resolution. The difference between the par value and estimated fair value of ordinary shares on the grant date was recorded as a one-time share-based compensation expense of RMB5,953,717 in general and administration expenses. No such transaction took place during the years ended December 31, 2017 and 2019.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Taxes
Income Taxes	18. Income Taxes Cayman Islands Under the current laws of the Cayman Islands, the Company is not subject to tax on income or capital gain arising in Cayman Islands. Additionally, upon payments of dividends by the Company to its shareholders, no Cayman Islands withholding tax will be imposed. Hong Kong Walnut HK is incorporated in Hong Kong and is subject to Hong Kong profits tax at the rate of 16.5% on its activities conducted in Hong Kong and it may be exempted from income tax on its foreign-derived income and there are no withholding taxes in Hong Kong on remittance of dividends. PRC The Company’s subsidiaries and VIE in the PRC are subject to the statutory rate of 25%, in accordance with the Enterprise Income Tax law (the ”EIT Law”), which was effective since January 1, 2008, except for certain entities eligible for preferential tax rates. Shanghai Xunmeng, a subsidiary of VIE, was recognized as a high and new technology enterprise (“HNTE”) in November 2018 and was eligible for 15% preferential tax rate from 2018 to 2020. 18. Income Taxes (Continued) PRC (Continued) In April 2018, Xinzhijiang, a subsidiary located in Qianhai District, Shenzhen, Guangdong Province, was eligible for a preferential tax rate of 15% and started to apply this rate from then on. The preferential tax rate is awarded to companies that are located in Qianhai District which operate in certain encouraged industries, from 2014 to 2020. Dividends, interests, rent or royalties payable by the Company’s PRC subsidiaries, to non-PRC resident enterprises, and proceeds from any such non-resident enterprise investor’s disposition of assets (after deducting the net value of such assets) shall be subject to 10% withholding tax, unless the respective non-PRC resident enterprise’s jurisdiction of incorporation has a tax treaty or arrangements with China that provides for a reduced withholding tax rate or an exemption from withholding tax. The Group’s loss before income taxes consisted of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Non-PRC ​ (108,086) ​ (7,083,904) (2,741,219) (393,751) PRC ​ (417,029) ​ (3,133,221) (4,226,384) (607,083) ​ ​ (525,115) ​ (10,217,125) (6,967,603) (1,000,834) ​ The Group had no current income The reconciliations of the income tax expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Loss before income tax expense (525,115) ​ (10,217,125) (6,967,603) (1,000,834) ​ PRC statutory tax rate 25 % 25 % 25 % 25 % Income tax benefits at PRC statutory tax rate (131,279) ​ (2,554,281) (1,741,901) (250,208) ​ International tax rate differential 27,074 ​ 1,779,100 735,028 105,580 ​ Preferential tax rate ​ — ​ 197,828 ​ 358,796 ​ 51,538 ​ Non-deductible expenses 6,890 ​ 36,726 (5,980) (859) ​ Non-taxable income (11,962) ​ (20,973) (61,151) (8,784) ​ Loss not recognized ​ 22,747 ​ — ​ — ​ — ​ Deferred tax items tax rate differential ​ — ​ (34,236) ​ (570,382) ​ (81,930) ​ Additional deduction of research and development expenses ​ — ​ (22,672) ​ (67,628) ​ (9,714) ​ Change in valuation allowance 86,530 ​ 618,508 1,353,218 194,377 ​ Income tax expenses — ​ — — — ​ ​ 18. Income Taxes (Continued) PRC (Continued) The significant components of the Group’s deferred tax assets were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ US$ Deferred tax assets ​ ​ ​ ​ ​ ​ Tax losses carried forward ​ 343,809 1,840,246 264,335 Carryforwards of non-deductible advertising expenses and donations ​ 424,883 ​ 251,829 ​ 36,173 Others ​ 13,276 ​ 43,111 ​ 6,193 Less: valuation allowance ​ (781,968) (2,135,186) (306,701) Deferred tax assets, net ​ — — — ​ The Group operates through several subsidiaries, the VIE and the subsidiaries of the VIE. Realization of the net deferred tax assets is dependent on factors including future reversals of existing taxable temporary differences and adequate future taxable income, exclusive of reversing deductible temporary differences and tax loss or credit carry forwards. The Group evaluates the potential realization of deferred tax assets on an entity-by-entity basis. As of December 31, 2018 and 2019, valuation allowances were provided against deferred tax assets in entities where it was determined it was more likely than not that the benefits of the deferred tax assets will not be realized. As of December 31,2018 and 2019, the Group had taxable losses of RMB1,551,301 and RMB8,174,339 (US$1,174,170) derived from entities in the PRC, which can be carried forward for five years to offset future taxable profit , and the period was extended to ten years for entities qualified as HNTE in 2019 and thereafter. The PRC taxable loss will expire from December 31, 2020 to 2029 if not utilized. The Group plans to indefinitely reinvest the undistributed earnings of its subsidiaries, the VIE and the subsidiaries of the VIE located in the PRC. As of December 31, 2018 and 2019, there were no undistributed earnings from these entities and no withholding tax has been accrued. As of December 31, 2018 and 2019, the Group did not have significant unrecognized tax benefit, all of which were presented on a net basis against the deferred tax assets related to tax loss carry forwards on the consolidated balance sheets. It is possible that the amount of unrecognized benefit will further change in the next 12 months; however, an estimate of the range of the possible change cannot be made at this moment. For the years ended December 31, 2017, 2018 and 2019, no interest expense was accrued in relation to the unrecognized tax benefit. As of December 31, 2018 and 2019 there were no accumulated interest expenses recorded in unrecognized tax benefit. As of December 31, 2019, the tax years ended December 31, 2014 through period ended as of the reporting dates for the WFOE, the VIE and the subsidiaries of the VIE remain open to examination by the PRC tax authorities.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions
Related Party Transactions	19. Related Party Transactions (a) Related parties ​ Names of related parties Relationship with the Group Tencent and its affiliates (“Tencent Group”) ​ A shareholder of the Company Toshare Group Holding Limited (1) ​ Company controlled by the Founder Suzhou Lebei Network Technology Co., Ltd (2) ​ Company controlled by one of the directors of the Company Ningbo Hexin Equity Investment Partnership ​ Company controlled by one of the executive officers of the Company (1) Toshare Group Holding Limited was no longer a related party of the Company since September 2019. (2) Suzhou Lebei Network Technology Co., Ltd was no longer a related party of the Company since June 2018. (b) Other than disclosed elsewhere, the Group had the following significant related party transactions for the years ended December 31, 2017, 2018 and 2019, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Services received from: ​ ​ ​ ​ ​ ​ ​ ​ Tencent Group 516,014 ​ 1,266,362 2,298,074 330,098 Suzhou Lebei Network Technology Co., Ltd 2,444 ​ — — — ​ (c) The Group had the following significant related party balances as of December 31, 2018 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ 2019 ​ RMB RMB US$ Accounts due from related parties: Current: Tencent Group* 1,018,963 1,905,793 273,750 Ningbo Hexin Equity Investment Partnership ** — 459,632 66,022 Accounts due to related parties: ​ ​ ​ Current: ​ ​ ​ ​ ​ ​ Toshare Group Holding Limited 19,966 — — Tencent Group 458,147 1,502,892 215,877 * The balance represents receivables due from the online payment platform operated by Tencent Group. ** The balance represents a loan to Ningbo Hexin Equity Investment Partnership, an entity controlled by one of the executive officers of the Company.

Loss Per Share

Loss Per Share	12 Months Ended
	Dec. 31, 2019
Loss Per Share
Loss Per Share	20. Loss Per Share The following table sets forth the computation of basic and diluted net loss per share for the following periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2017 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ Net loss ​ (525,115) ​ (10,217,125) (6,967,603) (1,000,834) Deemed distribution to certain holders of convertible preferred shares ​ — ​ (80,496) — — Contribution from certain holder of convertible preferred shares ​ 26,413 ​ — — — Net loss attributable to ordinary shareholders ​ (498,702) ​ (10,297,621) (6,967,603) (1,000,834) ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator (in thousands of shares): ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average number of ordinary shares outstanding – basic and diluted ​ 1,764,799 ​ 2,968,320 4,627,278 4,627,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss per share – basic and diluted ​ (0.28) ​ (3.47) (1.51) (0.22)

Restricted Net Assets

Restricted Net Assets	12 Months Ended
	Dec. 31, 2019
Restricted Net Assets
Restricted Net Assets	21. Restricted Net Assets The Company’s ability to pay dividends is primarily dependent on the Company receiving distributions of funds from its subsidiaries, the VIE and subsidiaries of the VIE. Relevant PRC statutory laws and regulations permit payments of dividends by the Company’s PRC subsidiaries, the VIE and subsidiaries of the VIE only out of their retained earnings, if any, as determined in accordance with PRC accounting standards and regulations. The results of operations reflected in the consolidated financial statements prepared in accordance with U.S. GAAP differ from those reflected in the statutory financial statements of the Company’s subsidiaries, the VIE and subsidiaries of the VIE. In accordance with the PRC Regulations on Enterprises with Foreign Investment and the articles of association of the Company’s PRC subsidiaries, a foreign-invested enterprise established in the PRC is required to provide certain statutory reserves, namely general reserve fund, the enterprise expansion fund and staff welfare and bonus fund which are appropriated from net profit as reported in the enterprise’s PRC statutory accounts. A foreign-invested enterprise is required to allocate at least 10% of its annual after-tax profit to the general reserve fund until such reserve has reached 50% of its respective registered capital based on the enterprise’s PRC statutory accounts. Appropriations to the enterprise expansion fund and staff welfare and bonus fund are at the discretion of the board of directors for all foreign-invested enterprises. The aforementioned reserves can only be used for specific purposes and are not distributable as cash dividends. The WFOE was established as a foreign-invested enterprise and, therefore, is subject to the above mandated restrictions on distributable profits. For the years ended December 31, 2017, 2018 and 2019, WFOE did not have after-tax profit and therefore no statutory reserves have been allocated. Foreign exchange and other regulations in the PRC may further restrict the Company’s VIE from transferring funds to the Company in the form of dividends, loans and advances. Amounts restricted include paid-in capital and statutory reserves of the Company’s PRC Subsidiaries and the equity of the VIE, as determined pursuant to PRC generally accepted accounting principles. As of December 31, 2019, restricted net assets of the Company’s PRC subsidiaries, the VIE and subsidiaries of the VIE were RMB8,344,790 (US$1,198,654).

Mainland China Employee Contrib

Mainland China Employee Contribution Plan	12 Months Ended
	Dec. 31, 2019
Mainland China Employee Contribution Plan
Mainland China Employee Contribution Plan	22. Mainland China Employee Contribution Plan As stipulated by the regulations of the PRC, full-time employees of the Group are entitled to various government statutory employee benefit plans, including medical insurance, maternity insurance, workplace injury insurance, unemployment insurance and pension benefits through a PRC government-mandated multi-employer defined contribution plan. The Group is required to make contributions to the plan based on certain percentages of employees’ salaries. The total expenses the Group incurred for the plan were RMB30,795, RMB133,699 and RMB334,434 (US$48,038) for the years ended December 31, 2017, 2018 and 2019, respectively. ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments and Contingencies.
Commitments and Contingencies	23. Commitments and Contingencies (a) Operating lease commitments The Company leases offices for operation under operating leases. Future minimum lease payments under non-cancellable operating leases with initial terms in excess of one year included in is Note 8. ​ (b) Investment commitments The Group's investment commitments primarily relate to capital contributions obligation under certain arrangement which does not have contractual maturity date. The total investment commitments contracted but not yet reflected in the financial statements amounted to USD16,000. (c) Contingencies In the ordinary course of business, the Group is from time to time involved in legal proceedings and litigations relating to disputes relating to trademarks and other intellectual property, among others. In July 2018, a complaint was filed against us in the U.S. federal court alleging contributory trademark infringement and unfair competition based on certain allegedly counterfeit and unauthorized merchandise sold by merchants to U.S. consumers on the platform. In August, 2019, the court dismissed all claims against the Group. Between August and December 2018, several putative shareholder class action lawsuits were filed against the Group and certain of its officers and directors in the U.S. District Court for the Southern District of New York (“SDNY”) and the Superior Court of the State of California. In March 2020, the court granted the Group’s motion to dismiss the claims in the consolidated action in the SDNY. The California action remains in its preliminary stages, for which, the Group cannot reliably estimate the likelihood of an unfavorable outcome or any estimate of the amounts or range of any potential loss. As of December 31, 2019, the Group did not consider an unfavorable outcome in any material respects in the outstanding legal proceedings and litigations to be probable. (d) Income Taxes As disclosed in Note 18, the Group had unrecognized tax benefits. The final outcome of the tax uncertainty is dependent upon various matters including tax examinations, interpretation of tax laws or expiration of statutes of limitation. However, due to the uncertainties associated with the status of examinations, including the protocols of finalizing audits by the relevant tax authorities, there is a high degree of uncertainty regarding the future cash outflows associated with these tax uncertainties.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events
Subsequent Events	24. Subsequent Events Beginning in January 2020, the emergence and wide spread of the novel Coronavirus ("COVID-19") has resulted in quarantines, travel restrictions, and the temporary closure of stores and facilities in China and elsewhere. Substantially all of the Group's revenues and workforce are concentrated in China. Consequently, the COVID-19 outbreak as a pandemic may adversely affect the Group’s business operations, financial condition and operating results for 2020, including but not limited to negative impact to the Group's total revenues and downward adjustments or impairment to the Group's non-current assets. Because of the significant uncertainties surrounding the COVID-19 outbreak, the extent of the business disruption and the related impact on the overall financial performance and outlook in 2020 cannot be reasonably estimated at this time. On March 31, 2020, the Company announced that certain long-term investors have agreed to purchase through a private placement a total of US$1.1 billion of newly issued Class A ordinary shares of the company, representing approximately 2.8% of the company's total outstanding shares. The transaction was closed in early April 2020. In April 2020, the Group entered into a subscription agreement in relation to the subscription of US$200 million convertible bonds issued by a third party listed on the Hong Kong Exchange. The convertible bonds bear interests at the coupon rate of 5% per annum with the maturity date falling on the third anniversary of the issue date, which may be extended to the fifth anniversary of the issue date at the election of the Group. ​

Condensed Financial Information

Condensed Financial Information of the Company	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information of the Company
Condensed Financial Information of the Company	25. Condensed Financial Information of the Company The following is the condensed financial information of the Company on a parent company only basis. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ RMB RMB US$ ASSETS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current assets ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ 5,541,746 661,714 95,049 Short-term investments ​ 6,260,689 ​ 6,157,221 ​ 884,429 Prepayments and other current assets ​ 18,789 17,906 2,572 Total current assets ​ 11,821,224 6,836,841 982,050 Non-current assets ​ ​ ​ ​ ​ ​ Intangible asset ​ 2,579,338 ​ 1,994,292 ​ 286,462 Investments in subsidiaries, the VIE and subsidiaries of the VIE ​ 4,440,777 21,053,370 3,024,127 Total non-current assets ​ 7,020,115 23,047,662 3,310,589 Total assets ​ 18,841,339 29,884,503 4,292,639 ​ ​ ​ ​ ​ ​ ​ LIABILITIES AND SHAREHOLDERS' EQUITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ ​ Accrued expenses and other liabilities ​ 18,745 23,566 3,385 Total current liabilities ​ 18,745 23,566 3,385 ​ ​ ​ ​ ​ ​ ​ Convertible bonds ​ — 5,206,682 747,893 Other non-current liabilities ​ — 7,389 1,061 Total non-current liabilities ​ — 5,214,071 748,954 Total liabilities ​ 18,745 5,237,637 752,339 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shareholders’ equity Class A ordinary shares (US$ 0.000005 par value; 77,300,000,000 shares authorized, 2,381,240,988 issued and outstanding as of December 31, 2018; 77,300,000,000 shares authorized, 2,575,580,988 issued and outstanding as of December 31, 2019) 78 84 12 Class B ordinary shares (US$ 0.000005 par value; 2,200,000,000 authorized, 2,074,447,700 issued and outstanding as of December 31, 2018 and 2019) 64 64 9 Additional paid-in capital 29,114,527 41,493,949 5,960,233 Accumulated other comprehensive income 1,035,783 1,448,230 208,025 Accumulated deficits (11,327,858) (18,295,461) (2,627,979) Total shareholders' equity 18,822,594 24,646,866 3,540,300 Total liabilities and shareholders’ equity 18,841,339 29,884,503 4,292,639 ​ ​ 25. Condensed Financial Information of the Company (Continued) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 ​ 2019 ​ RMB ​ RMB RMB US$ Costs of revenues ​ ​ ​ ​ ​ ​ ​ ​ Costs of online marketplace services ​ — ​ (491,069) ​ (619,733) ​ (89,019) Total costs of revenues ​ — ​ (491,069) ​ (619,733) ​ (89,019) Sales and marketing expenses ​ — ​ (4,106) ​ (47,746) ​ (6,858) General and administrative expenses (165) ​ (4,101) (3,245) (466) Total operating expenses (165) ​ (8,207) (50,991) (7,324) Operating loss (165) ​ (499,276) (670,724) (96,343) Interest income 8,264 ​ 207,597 318,166 45,702 Interest expense ​ — ​ — ​ (144,132) ​ (20,703) Foreign exchange gain — ​ 113 — — Other loss — ​ — (31) (4) Share of losses from subsidiaries, the VIE and subsidiaries of the VIE (533,214) ​ (9,925,559) (6,470,882) (929,484) Loss before income tax (525,115) ​ (10,217,125) (6,967,603) (1,000,832) Income tax expenses ​ — ​ — ​ — ​ — Net loss (525,115) ​ (10,217,125) (6,967,603) (1,000,832) ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive income, net of tax of nil ​ Foreign currency translation difference, net of tax of nil (47,681) ​ 1,058,884 412,447 59,244 Comprehensive loss (572,796) ​ (9,158,241) (6,555,156) (941,588) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ RMB ​ RMB RMB US$ Net cash generated from operating activities ​ 2,753 ​ 110,724 259,409 37,262 Cash flows from investing activities: ​ ​ ​ Proceeds from sales of short-term investments ​ — ​ — ​ 6,049,590 868,969 Cash given to purchase of short-term investments ​ — ​ (6,146,370) ​ (5,998,024) ​ (861,562) Cash given to subsidiaries, the VIE and subsidiaries of the VIE ​ (1,058,908) ​ (6,749,831) ​ (20,293,132) (2,914,926) Net cash used in investing activities ​ (1,058,908) ​ (12,896,201) ​ (20,241,566) (2,907,519) Cash flows from financing activities: ​ ​ ​ ​ ​ ​ Proceeds from initial public offering ​ — ​ 11,879,944 — — Costs incurred for the initial public offering costs ​ — ​ (356,313) ​ — ​ — Proceeds from follow-on offering ​ — ​ — 8,194,597 1,177,080 Costs incurred for the issuance costs of follow-on offering ​ — ​ — ​ (200,769) ​ (28,839) Proceeds from issuance of convertible bonds ​ — ​ — 7,073,101 1,015,987 Costs incurred for the issuance of convertible bonds ​ — ​ — ​ (106,344) ​ (15,275) Proceeds from issuance of convertible preferred shares ​ 1,446,906 ​ 5,824,568 ​ — ​ — Costs incurred for the issuance at convertible preferred shares ​ (15,369) ​ (3,842) ​ — ​ — Repurchase of Class B Ordinary Shares ​ (32,677) ​ — — — Net cash generated from financing activities ​ 1,398,860 ​ 17,344,357 14,960,585 2,148,953 Exchange rate effect on cash, cash equivalents and restricted cash ​ (47,820) ​ 319,221 141,540 20,331 Net increase/(decrease) in cash, cash equivalents and restricted cash ​ 294,885 ​ 4,878,101 (4,880,032) (700,973) Cash, cash equivalents and restricted cash at beginning of year ​ 368,760 ​ 663,645 5,541,746 796,022 Cash, cash equivalents and restricted cash at end of year ​ 663,645 ​ 5,541,746 661,714 95,049 ​ 25. Condensed Financial Information of the Company (Continued) Basis of presentation Condensed financial information is used for the presentation of the Company, or the parent company. The condensed financial information of the parent company has been prepared using the same accounting policies as set out in the Company’s consolidated financial statements except that the parent company used the equity method to account for investment in its subsidiaries, the VIE and subsidiaries of the VIE. The parent company records its investment in its subsidiaries, the VIE and its subsidiaries under the equity method of accounting as prescribed in ASC 323, Investments-Equity Method and Joint Ventures. Such investments are presented on the condensed balance sheets as ''Investments in subsidiaries, the VIE and a subsidiaries of the VIE'' or ''Loss in excess of investments in subsidiaries, the VIE and subsidiaries of the VIE'' and their respective loss as ''Share of loss in subsidiaries, the VIE and a subsidiaries of the VIE'' on the condensed statements of comprehensive loss. Equity method accounting ceases when the carrying amount of the investment, including any additional financial support, in subsidiaries, the VIE and subsidiaries of the VIE is reduced to zero unless the parent company has guaranteed obligations of the subsidiaries, the VIE and subsidiaries of the VIE or is otherwise committed to provide further financial support. If the subsidiaries, the VIE subsidiaries of the VIE subsequently reports net income, the parent company shall resume applying the equity method only after its share of that net income equals the share of net loss not recognized during the period the equity method was suspended. The parent company’s condensed financial statements should be read in conjunction with the Company’s consolidated financial statements.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Basis of presentation	(a) Basis of presentation The accompanying consolidated financial statements have been prepared in accordance with the accounting principles generally accepted in the United States of America (“US GAAP”).
Principles of consolidation	(b) Principles of consolidation The consolidated financial statements include the financial statements of the Company, its subsidiaries, the VIE and the subsidiaries of the VIE. All significant inter-company transactions and balances between the Company, its subsidiaries, the VIE and subsidiaries of the VIE have been eliminated upon consolidation.
Use of estimates	(c) Use of estimates The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the balance sheet dates and revenues and expenses during the reporting periods. Significant accounting estimates reflected in the Group’s consolidated financial statements include, but not limited to provision for prepayments made on behalf of merchants, economic lives and impairment of long-lived assets, valuation of short-term and long-term investments, valuation allowance for deferred tax assets, uncertain tax position, valuation for share-based compensation, liability component of convertible bonds and incremental borrowing rates for operating lease liabilities. Changes in facts and circumstances may result in revised estimates. Actual results could differ from those estimates, and as such, differences may be material to the consolidated financial statements.
Foreign currency	(d) Foreign currency The functional currency of the Company and its overseas subsidiaries is the US$. The Company’s PRC subsidiaries, the VIE and subsidiaries of the VIE determined their functional currencies to be RMB based on the criteria of ASC 830, Foreign Currency Transactions denominated in foreign currencies are re-measured into the functional currency at the exchange rates prevailing on the transaction dates. Monetary assets and liabilities denominated in foreign currencies are re-measured at the exchange rates prevailing at the balance sheet date. Non-monetary items that are measured in terms of historical cost in foreign currency are re-measured using the exchange rates at the dates of the initial transactions. Exchange gains and losses are included in the consolidated statements of comprehensive loss. The Company uses the average exchange rate for the year and the exchange rate at the balance sheet date to translate the operating results and financial position, respectively. Translation differences are recorded in accumulated other comprehensive income/(loss), a component of shareholders’ (deficits)/ equity.
Convenience translation	(e) Convenience translation Amounts in US$ are presented for the convenience of the reader and are translated at the noon buying rate of US$1.00 to RMB6.9618 on December 31, 2019, the last business day in December 2019, as published on the website of the United States Federal Reserve Board. No representation is made that the RMB amounts could have been, or could be, converted into US$ at such rate.
Cash and cash equivalents	(f) Cash and cash equivalents Cash and cash equivalents consist of cash on hand and highly liquid investments which are unrestricted as to withdrawal or use and have original maturities of three months or less when purchased.
Restricted cash	(g) Restricted cash Restricted cash mainly represents cash received from consumers and reserved in a bank supervised account for payments to merchants.
Short-term investments	(h) Short-term investments All highly liquid investments with original maturities of greater than three months but less than twelve months, are classified as short-term investments. Investments that are expected to be realized in cash during the next twelve months are also included in short-term investments. The Group accounts for short-term debt investments in accordance with ASC Topic 320 (“ASC 320”), Investments — Debt Securities Investments — Equity Securities . Short-term debt investments include time deposits and wealth management products in financial institutions that the Group has positive intent and ability to hold to maturity, both of which are categorized as “held to maturity”. Wealth management products with the intention to sell in the near term are classified as trading securities and measured at fair value. The Company also holds marketable equity securities in a listed company and measures it at fair value. Any realized gains or losses on the sale of the short-term investments are determined on a specific identification method and are reflected in earnings during the period in which gains or losses are realized. Realized and unrealized gains and losses and interest income from the short-term investments are recorded in “Interest and investment gain, net” in the consolidated statements of comprehensive loss.
Property, equipment and software, net	(i) Property, equipment and software, net Property, equipment and software are stated at cost and are depreciated and amortized using the straight-line method over the estimated useful lives of the assets, as follows: ​ ​ ​ ​ Category Estimated useful life Computer and office equipment 3 years Purchased software ​ 3 Leasehold improvements Over the shorter of lease terms or the estimated useful lives of the assets ​ Repair and maintenance costs are charged to expense as incurred, whereas the costs of renewals and betterments that extend the useful lives of property, equipment and software are capitalized as additions to the related assets. Retirements, sales and disposals of assets are recorded by removing the cost and accumulated depreciation from the asset and accumulated depreciation accounts with any resulting gain or loss reflected in the consolidated statements of comprehensive loss. Direct costs that are related to the construction of property, equipment and software and incurred in connection with bringing the assets to their intended use are capitalized as construction in progress. Construction in progress is transferred to specific property, equipment and software, and the depreciation of these assets commences when the assets are ready for their intended use.
Equity method investments	(j) Equity method investments The Group accounts for its investments in common stock or in-substance common stock in entities in which it can exercise significant influence but does not own a majority equity interest or control using the equity method of accounting in accordance with ASC Subtopics 323-10 ("ASC 323-10"), Investments-Equity Method and Joint Ventures: Overall
Impairment of long-lived assets other than goodwill	(k) Impairment of long-lived assets other than goodwill The Group evaluates its long-lived assets, including fixed assets and intangible assets with finite lives, for impairment whenever events or changes in circumstances, such as a significant adverse change to market conditions that will impact the future use of the assets, indicate that the carrying amount of an asset may not be fully recoverable. When these events occur, the Group evaluates the recoverability of long-lived assets by comparing the carrying amounts of the assets to the future undiscounted cash flows expected to result from the use of the assets and their eventual disposition. If the sum of the expected undiscounted cash flows is less than the carrying amounts of the assets, the Group recognizes an impairment loss based on the excess of the carrying amounts of the assets over their fair value. Fair value is generally determined by discounting the cash flows expected to be generated by the assets, when the market prices are not readily available. For all periods presented, there were no impairment of any of the Group’s long-lived assets.
Fair value of financial instruments	(l) Fair value of financial instruments The Group’s financial instruments include cash and cash equivalents, restricted cash, receivables from payment platforms, amount due from/to related parties, prepayment made on behalf of merchants, merchant deposits, customer advances, payables to merchants, short-term investments and convertible bonds. For the aforementioned financial instruments included in current assets and liabilities, except for ones measured at fair value, their carrying amount approximated to their respective fair values because of the general short maturities. The fair value of convertible bonds that are not reported at fair value are disclosed in Note 14. The Group applies ASC 820, Fair Value Measurements and Disclosures ASC 820 establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows: Level 1 — Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2 — Other inputs that are directly or indirectly observable in the marketplace. 2. Summary of Significant Accounting Policies (Continued) (l) Fair value of financial instruments (Continued) Level 3 — Unobservable inputs which are supported by little or no market activity. ASC 820 describes three main approaches to measuring the fair value of assets and liabilities: (1) market approach; (2) income approach; and (3) cost approach. The market approach uses prices and other relevant information generated from market transactions involving identical or comparable assets or liabilities. The income approach uses valuation techniques to convert future amounts to a single present value amount. The measurement is based on the value indicated by current market expectations about those future amounts. The cost approach is based on the amount that would currently be required to replace an asset.
Revenue recognition	(m) Revenue recognition The Group through its platform primarily offers online marketplace services that enable third-party merchants to sell their products to consumers in China. Revenues from online marketplace services consist of online marketing services revenues and transaction services fees. Payments for services are generally received before deliveries. Effective January 1, 2018, the Group adopted ASU 2014-09, Revenue from contracts with Customers (Topic 606), The Group presents value added taxes (“VAT”) as reductions of revenues. Online marketplace services The Group charges fees for transaction services to merchants for sales transactions completed on the Group’s online marketplace, where the Group does not take control of the products provided by the merchants at any point in the time during the transactions and does not have latitude over pricing of the merchandise. Transaction services fee is determined as a percentage based on the value of merchandise being sold by the merchants. Revenues related to transaction services are recognized in consolidated statements of comprehensive loss at the time when the Group’s service obligations to the merchants are determined to have been completed under each sales transaction upon the consumers’ confirming the receipts of goods. Fees charged for transaction services are not refundable if and when consumers return the merchandise to merchants. The Group also entered into contractual agreements with certain merchants to provide online marketing services on the Group’s online marketplace for which the Group receives service fees from merchants. Online marketing services allow merchants to bid for keywords that match product listings appearing in search or browser results on the Group’s online marketplace. Merchants prepay for online marketing services that are charged on a cost-per-click basis. The Group provides the online marketing services on its own platforms without involvement of any other party. Under ASC 606, the related revenues are recognized at a point of time when consumers click the merchants’ product listings when services are completed by the Group for the merchants. The positioning of such listings and the price for such positioning are determined through an online auction system, which facilitates price discovery through a market-based mechanism. 2. Summary of Significant Accounting Policies (Continued) (m) Revenue recognition (Continued) The Group provides sales incentives to certain merchants that entitle them to receive price reduction on the online marketplace services by meeting certain requirements. The Group nets the sales incentives against online marketplace services revenues. In order to promote its online marketplace and attract more registered consumers, the Group at its own discretion offers various forms of incentives, for example, coupons, credits and discounts that are not specific to any merchant, to consumers that are not customers of the Group. Evaluation of the varying features of different incentive programs were made to determine that incentives offered to consumers are generally not considered as payments to customers. Such evaluation included the consideration of whether the incentives represent implicit obligation to consumers on behalf of merchants and if so, whether the consumers would be considered as customers of the Group. Coupons and credits redeemable for coupons can only be used for future purchases of eligible merchandise offered on the Group’s online marketplace to reduce purchase price. As the consumers are required to make future purchases of the merchants’ merchandise to redeem the coupons, the Group recognizes the amounts of redeemed coupons primarily as marketing expenses when future purchases are made. Discounts provided to consumers are recognized as marketing expenses when the related transaction services revenues are recognized. During the years ended December 31, 2018 and 2019, the Group also issued to consumers at its discretion, cash redeemable credits upon their completion of certain actions unrelated to the purchases of any specific merchant products on the Group’s online marketplace. As the credits were redeemable for cash, the Group accrued for the related costs in marketing expenses based on the cash redemption value of each credit as it is issued, assuming all credits will be redeemed. As of December 31, 2018 and 2019, the amount of outstanding credits were immaterial.
Costs of revenues	(n) Costs of revenues Costs of online marketplace services consist primarily of payment processing fees paid to third party online payment platforms, costs associated with the operation of the Group’s platform, such as call center and merchant support costs, bandwidths and server costs, amortization, depreciation and maintenance costs, staff costs and share-based compensation expenses, surcharges and other expenses directly attributable to the online marketplace services.
Advertising expenditures	(o) Advertising expenditures Advertising expenditures are expensed when incurred and are included in sales and marketing expenses. Total amount of advertising expenditures and incentive programs recognized in sales and marketing expenses were RMB1,259,610, RMB12,867,833 and RMB25,867,772 (US$3,715,673) for the years ended December 31, 2017, 2018 and 2019, respectively.
Research and development expenses	(p) Research and development expenses Research and development expenses include payroll, employee benefits, and other operating expenses associated with research and platform development. Research and development expenses also include rent, depreciation and other related expenses. To date, expenditures incurred between when the application has reached the development stage and when it is substantially complete and ready for its intended use have been inconsequential and, as a result, the Company did not capitalize any software development costs in the accompanying consolidated financial statements.
Leases	2. Summary of Significant Accounting Policies (Continued) (q) Leases The Group adopted ASU No. 2016-02, Leases (Topic 842) ("ASU 2016-02"), effective January 1, 2019 using the modified retrospective method and did not restate comparable periods. The Group elected the package of practical expedients permitted under the transition guidance, which allowed the Group to carry forward the historical lease classification for any expired or existing contract and the accounting for the initial direct costs on those leases on the adoption date. The Group also elected the practical expedient of the short-term lease exemption for contracts with lease terms of 12 months or less. The Group as the lessee determines if an arrangement is a lease at inception. Leases are classified as operating or finance leases in accordance with the recognition criteria in ASC 842-20-25. The Group's lease portfolio consisted entirely of operating leases as of January 1 and December 31, 2019. The Group's leases do not contain any residual value guarantees or material restrictive covenants. At the commencement date of an operating lease, the Group records a right-of-use ("ROU") asset and lease liability based on the present value of the lease payments over the lease term. Variable lease payments not dependent on an index or rate are excluded from the ROU asset and lease liability calculations and are recognized in expense in the period which the obligation for those payments is incurred. As the rate implicit in the Group's lease is not typically readily available, the Group uses an incremental borrowing rate based on the information available at the lease commencement date in determining the present value of lease payments. This incremental borrowing rate reflects the fixed rate at which the Group could borrow on a collateralized basis the amount of the lease payments in the same currency, for a similar term, in a similar economic environment. ROU assets include any lease prepayments and are reduced by lease incentives. Operating lease expense for lease payments is recognized on a straight-line basis over the lease term. Lease terms are based on the non-cancelable term of the lease and may contain options to extend the lease when it is reasonably certain that the Group will exercise that option. The cumulative effects of changes made to the Group's condensed consolidated balance sheet on January 1, 2019 for the adoption of ASU 2016-02 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ Balance at ​ ​ December ​ ​ ​ January 1, ​ ​ 31, 2018 ​ Adjustments ​ 2019 ​ RMB RMB RMB US$ Assets: Prepayments and other current assets 953,989 ​ (2,768) ​ 951,221 ​ 136,634 Right-of-use assets — ​ 221,521 ​ 221,521 ​ 31,820 Liabilities: ​ ​ ​ Current portion of lease liabilities — ​ 55,180 ​ 55,180 ​ 7,926 Non-current portion of lease liabilities — ​ 174,681 ​ 174,681 ​ 25,091 Accrued expenses and other liabilities 2,225,667 ​ (11,108) ​ 2,214,559 ​ 318,101 ​ As of January 1, 2019, the difference between the lease liabilities and right-of-use assets related to the reversal of existing deferred rent and prepaid rent balances is RMB11,108 (US$1,596) and RMB2,768 (US$398), respectively. The adoption of the standard did not impact the Company's consolidated statements of comprehensive loss and cash flows.
Income taxes	(r) Income taxes The Group follows the liability method of accounting for income taxes in accordance with ASC 740 (‘‘ASC 740’’), Income Taxes. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial reporting and tax bases of assets and liabilities using enacted tax rates that will be in effect in the period in which the differences are expected to reverse. The Group records a valuation allowance to offset deferred tax assets if based on the weight of available evidence, it is more-likely-than-not that some portion, or all, of the deferred tax assets will not be realized. The effect on deferred taxes of a change in tax rate is recognized in tax expense in the period that includes the enactment date of the change in tax rate. The Group accounted for uncertainties in income taxes in accordance with ASC 740. Interest and penalties related to unrecognized tax benefit recognized in accordance with ASC 740 are classified in the consolidated statements of comprehensive loss as income tax expenses.
Share-based compensation	(s) Share-based compensation The Group applies ASC 718 (‘‘ASC 718’’), Compensation—Stock Compensation, to account for its employee share-based payments. In accordance with ASC 718, the Group determines whether an award should be classified and accounted for as a liability award or an equity award. All of the Group’s share-based awards to employees were classified as equity awards. The Group measures the employee share-based compensation based on the fair value of the award at the grant date. Expense is recognized using accelerated method over the requisite service period. The fair value of share options at the time of grant is determined using the binomial-lattice option pricing model. In accordance with ASU No. 2016-09, Compensation-Stock Compensation (Topic 718): Improvement to Employee Share-based Payment Accounting, the Group elected to account for forfeitures as they occurred.
Employee benefit expenses	(t) Employee benefit expenses As stipulated by the regulations of the PRC, full-time employees of the Group are entitled to various government statutory employee benefit plans, including medical insurance, maternity insurance, workplace injury insurance, unemployment insurance and pension benefits through a PRC government-mandated multi-employer defined contribution plan. The Group is required to make contributions to the plan and accrues for these benefits based on certain percentages of the qualified employees’ salaries.
Comprehensive loss	(u) Comprehensive loss Comprehensive loss is defined as the changes in equity of the Group during a period from transactions and other events and circumstances excluding transactions resulting from investments by owners and distributions to owners. Among other disclosures, ASC 220, Comprehensive Income, requires that all items that are required to be recognized under current accounting standards as components of comprehensive income be reported in a financial statement that is displayed with the same prominence as other financial statements. For each of the periods presented, the Group’s comprehensive loss includes net loss and foreign currency translation difference and is presented in the consolidated statements of comprehensive loss.
Loss per share	(v) Loss per share Basic loss per share is computed by dividing net loss attributable to ordinary shareholders by the weighted average number of ordinary shares outstanding during the period using the two-class method. Under the two-class method, net loss is allocated between ordinary shares and other participating securities based on their participating rights. Diluted loss per share is calculated by dividing net loss attributable to ordinary shareholders by the weighted average number of ordinary and dilutive ordinary equivalent shares outstanding during the period. Ordinary equivalent shares consist of shares issuable upon the exercise of share options and conversion of convertible bonds using the treasury stock method. Ordinary equivalent shares are not included in the denominator of the diluted loss per share calculation when inclusion of such shares would be anti-dilutive. Basic and diluted loss per share are not reported separately for Class A ordinary shares or Class B ordinary shares (the ''Ordinary Shares'') as each class of shares has the same rights to undistributed and distributed earnings.
Segment reporting	(w) Segment reporting The Group follows ASC 280, Segment Reporting. The Group’s Chief Executive Officer as the chief operating decision-maker reviews the consolidated financial results when making decisions about allocating resources and assessing the performance of the Group as a whole and hence, the Group has only one reportable segment. The Group operates and manages its business as a single segment. As the Group’s long-lived assets are substantially all located in the PRC and substantially all the Group revenues are derived from within the PRC, no geographical segments are presented.
Recent accounting pronouncements	(x) Recent accounting pronouncements The Company ceased to be an emerging growth company since December 31, 2018. In June 2016, the FASB issued Accounting Standards Update ("ASU") 2016-13: Financial Instruments-Credit Losses (Topic 326) Financial Instruments-Credit Losses (Topic 326): Targeted Transition Relief and ASU 2019-11 Codification Improvements to Topic 326, Financial Instruments-Credit losses. In August 2018, the FASB issued ASU No. 2018-13 (‘‘ASU 2018-13’’), Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement In January 2020, the FASB issued ASU 2020-01, Investments-Equity Securities (Topic 321), Investments- Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815)—Clarifying the Interactions between Topic 321, Topic 323, and Topic 815. This guidance addresses accounting for the transition into and out of the equity method and provides clarification of the interaction of rules for equity securities, the equity method of accounting, and forward contracts and purchase options on certain types of securities. This standard is effective for the Company beginning January 1, 2021 including interim periods within the fiscal year. Early adoption is permitted. The Company is still evaluating the impact on its consolidated financial statements.

Organization (Tables)

Organization (Tables)	12 Months Ended
	Dec. 31, 2019
Organization
Schedule of company's major subsidiaries, consolidated VIE and the subsidiary of the VIE	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Percentage of ​ ​ ​ Date of ​ Place of ​ ownership by the ​ Principal Entity ​ incorporation ​ incorporation ​ Company ​ activities ​ ​ ​ ​ ​ ​ Direct Indirect ​ ​ Subsidiaries: HongKong Walnut Street Limited ("Walnut HK") ​ April 28, 2015 Hong Kong 100 % — Holding company Hangzhou Weimi Network Technology Co., Ltd. ("Hangzhou Weimi" or the "WFOE") ​ May 28, 2015 PRC 100 % — Technology research and development Walnut Street (Shanghai) Information Technology Co., Ltd. ​ January 25,2018 PRC 100 % ​ Technology research and development Shenzhen Qianhai Xinzhijiang Information Technology Co., Ltd. (“Xinzhijiang”) ​ April 25, 2018 ​ PRC ​ 100 % — ​ E-commerce platform ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ VIE: ​ Hangzhou Aimi Network Technology Co., Ltd. ("Hangzhou Aimi" or the "VIE") ​ April 14, 2015 PRC — 100 % E-commerce platform ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ VIE’s subsidiary: ​ Shanghai Xunmeng Information Technology Co., Ltd. ("Shanghai Xunmeng") ​ January 9, 2014 PRC — 100 % E-commerce platform ​
Schedule of financial information for the VIE before eliminating the inter-company balances and transactions between the VIE, the subsidiaries of the VIE and other entities within the Group	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ RMB RMB US$ ASSETS ​ ​ ​ ​ ​ ​ ​ Current assets Cash and cash equivalents 3,529,316 2,816,894 404,622 Restricted cash 16,379,364 27,528,793 3,954,264 Receivables from online payment platforms 247,586 1,050,974 150,963 Short-term investments 1,300,000 6,560,665 942,381 Amounts due from related parties (i) 1,018,963 2,360,267 339,031 Amounts due from Group companies ​ 565,101 ​ 3,337,273 ​ 479,369 Prepayments and other current assets 441,590 295,377 42,428 Total current assets 23,481,920 43,950,243 6,313,058 ​ Non-current assets ​ ​ ​ ​ ​ Property, equipment and software, net 16,578 27,719 3,982 Right-of-use assets — 452,883 65,053 Other non-current assets — 60,306 8,662 Total non-current assets 16,578 540,908 77,697 Total assets ​ 23,498,498 44,491,151 6,390,755 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ RMB RMB US$ LIABILITIES Current liabilities Amounts due to related parties (i) 458,147 1,502,892 215,877 Amounts due to Group companies 1,575,534 5,393,858 774,779 Customer advances and deferred revenues 190,382 605,969 87,042 Payable to merchants 17,275,934 29,657,227 4,259,994 Accrued expenses and other liabilities 1,500,951 3,420,728 491,358 Merchant deposits 4,188,273 7,840,912 1,126,277 Short-term borrowings ​ — ​ 898,748 ​ 129,097 Lease liabilities ​ — ​ 90,523 ​ 13,003 Total current liabilities ​ 25,189,221 ​ 49,410,857 ​ 7,097,427 Lease liabilities ​ — ​ 382,673 ​ 54,968 Total non-current liabilities — 382,673 54,968 Total liabilities 25,189,221 49,793,530 7,152,395 i) Information with respect to related parties is discussed in Note 19. 1. Organization (Continued) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ RMB RMB RMB US$ Net revenues from ​ ​ ​ ​ ​ ​ ​ ​ Group companies 207,570 ​ 298,415 2,244,429 322,392 External 1,744,076 ​ 10,136,874 17,630,903 2,532,521 Net revenues 1,951,646 ​ 10,435,289 19,875,332 2,854,913 Net loss (8,924) ​ (1,552,789) (3,611,656) (518,782) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ RMB RMB RMB US$ Net cash generated from operating activities 10,391,383 ​ 8,984,498 11,139,572 1,600,099 Net cash generated from /(used in) investing activities 88,404 ​ (1,147,101) (5,249,046) (753,978) Net cash provided by financing activities 200,000 ​ 507,767 4,546,481 653,061 Net increase in cash, cash equivalents and restricted cash 10,679,787 ​ 8,345,164 10,437,007 1,499,182 ​

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Summary of Significant Accounting Policies
Schedule of estimated useful lives of the assets	​ ​ ​ ​ Category Estimated useful life Computer and office equipment 3 years Purchased software ​ 3 Leasehold improvements Over the shorter of lease terms or the estimated useful lives of the assets ​ Repair and maintenance costs are charged to expense as incurred, whereas the costs of renewals and betterments that extend the useful lives of property, equipment and software are capitalized as additions to the related assets. Retirements, sales and disposals of assets are recorded by removing the cost and accumulated depreciation from the asset and accumulated depreciation accounts with any resulting gain or loss reflected in the consolidated statements of comprehensive loss. Direct costs that are related to the construction of property, equipment and software and incurred in connection with bringing the assets to their intended use are capitalized as construction in progress. Construction in progress is transferred to specific property, equipment and software, and the depreciation of these assets commences when the assets are ready for their intended use.
Schedule of Group's condensed consolidated balance sheet	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ ​ ​ Balance at ​ ​ December ​ ​ ​ January 1, ​ ​ 31, 2018 ​ Adjustments ​ 2019 ​ RMB RMB RMB US$ Assets: Prepayments and other current assets 953,989 ​ (2,768) ​ 951,221 ​ 136,634 Right-of-use assets — ​ 221,521 ​ 221,521 ​ 31,820 Liabilities: ​ ​ ​ Current portion of lease liabilities — ​ 55,180 ​ 55,180 ​ 7,926 Non-current portion of lease liabilities — ​ 174,681 ​ 174,681 ​ 25,091 Accrued expenses and other liabilities 2,225,667 ​ (11,108) ​ 2,214,559 ​ 318,101

Short-term Investments (Tables)

Short-term Investments (Tables)	12 Months Ended
	Dec. 31, 2019
Short-term Investments
Schedule of Short-term investments classification	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ 2019 ​ ​ RMB ​ RMB ​ US$ Debt securities: ​ ​ ​ ​ ​ ​ Held-to-maturity 7,630,689 34,481,053 4,952,893 Trading — 795,849 114,317 Equity securities: ​ ​ ​ ​ ​ ​ Marketable — 11,925 1,713 ​ 7,630,689 35,288,827 5,068,923

Prepayments and Other Current_2

Prepayments and Other Current Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Prepayments and Other Current Assets
Schedule of components of prepayments and other current assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ 2019 ​ RMB RMB US$ Prepayments 667,113 645,169 92,673 Interest receivables 101,062 146,294 21,014 VAT recoverable 63,005 102,426 14,713 Rental and other deposits 64,902 12,060 1,732 Loan to a third party 35,000 — — Staff advances 7,868 4,020 577 Payments made on behalf of merchants 11,105 27,360 3,930 Provision for payments made on behalf of merchants ​ (3,249) ​ (15,032) ​ (2,159) Others 7,183 27,980 4,019 ​ 953,989 950,277 136,499 ​

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2019
Property, Equipment and Software, Net
Schedule of Property, equipment and software, net	​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ US$ At cost: ​ ​ ​ ​ ​ ​ Computer, office equipment and purchased software ​ 27,148 49,129 7,057 Leasehold improvement ​ 10,654 ​ 18,826 ​ 2,704 ​ ​ 37,802 ​ 67,955 ​ 9,761 Less: accumulated depreciation ​ (8,727) (26,682) (3,833) ​ ​ 29,075 41,273 5,928
Schedule of depreciation expenses allocated to captions in income statement	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Costs of revenues ​ 553 ​ 1,291 3,603 518 Sales and marketing expenses ​ 546 ​ 805 2,415 347 General and administrative expenses ​ 181 ​ 1,074 1,901 273 Research and development expenses ​ 985 ​ 2,764 10,179 1,462 ​ ​ 2,265 ​ 5,934 18,098 2,600

Intangible Asset (Tables)

Intangible Asset (Tables)	12 Months Ended
	Dec. 31, 2019
Intangible Asset
Schedule of intangible asset	​ ​ ​ ​ ​ Total ​ ​ RMB Balance as of January 1, 2018 — Addition 2,852,370 Amortization (491,069) Foreign currency translation difference 218,037 Balance as of December 31, 2018 ​ 2,579,338 Amortization ​ (619,733) Foreign currency translation difference ​ 34,687 Balance as of December 31, 2019 1,994,292
Schedule of estimated annual amortization expense	​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ RMB ​ US$ 2020 629,233 90,384 2021 627,514 90,137 2022 627,514 90,137 2023 110,031 15,805

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases
Summary of maturity analysis of the Company's operating lease liabilities and reconciliation of the undiscounted cash flows to the operating lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ Rental ​ ​ RMB ​ US$ ​ ​ ​ ​ ​ 2020 142,058 20,405 2021 150,231 21,579 2022 128,731 18,491 2023 94,598 13,588 2024 and after 97,558 14,013 Total undiscounted cash flows 613,176 88,076 Less: imputed interest (68,849) (9,888) Present value of lease liabilities 544,327 78,188
Summary of supplemental information related to leases	​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2019 ​ 2019 ​ RMB US$ ​ ​ ​ ​ ​ Operating cash flows for operating leases 76,130 10,935 ROU assets obtained in exchange for new operating lease liabilities 402,646 57,836

Accrued Expenses and Other Li_2

Accrued Expenses and Other Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Accrued Expenses and Other Liabilities
Schedule of accrued expenses and other liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ US$ Payroll payable 389,615 1,061,228 152,436 Accrued expenses 1,371,483 2,727,273 391,748 VAT and other tax payable 436,495 1,045,796 150,219 Others 28,074 42,765 6,144 ​ 2,225,667 4,877,062 700,547

Convertible Preferred Shares (T

Convertible Preferred Shares (Tables)	12 Months Ended
	Dec. 31, 2019
Convertible Preferred Shares
Summary of the issuances of convertible preferred shares	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Original Issuance ​ ​ ​ ​ ​ ​ Price per ​ Number of Name Issuance Date Share* Shares* Series A1 Convertible Preferred Shares ​ June 2015 ​ $ 0.0093 ​ 71,849,380 Series A2 Convertible Preferred Shares June 2015 ​ $ 0.0336 238,419,800 Series B1 Convertible Preferred Shares November 2015 ​ $ 0.1576 211,588,720 Series B2 Convertible Preferred Shares January 2016 ​ $ 0.1576 27,781,280 Series B3 Convertible Preferred Shares March 2016 ​ $ 0.1576 145,978,540 Series B4 Convertible Preferred Shares June 2016 ​ $ 0.1710 292,414,780 Series C1 Convertible Preferred Shares February 2017 ​ $ 0.3545 56,430,180 Series C2 Convertible Preferred Shares February 2017 ​ $ 0.3985 238,260,780 Series C3 Convertible Preferred Shares June 2017 ​ $ 0.4139 241,604,260 Series D Convertible Preferred Shares ​ March 2018** ​ $ 2.4832 ​ 551,174,340 * In connection with the issuance of Series D convertible preferred shares, the Company effected a change of authorized share capital (Note15), the Company’s then issued and outstanding Convertible Preferred Shares were split on a 1-to- 20 basis. The number of shares and per-share price in the consolidated financial statements were recasted on a retroactive basis to reflect the effect of these changes. ** Series D Convertible Preferred Shares were issued and converted in 2018. Therefore, the balance was nil as of December 31, 2018.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Measurements
Schedule of financial instruments measured at fair value on a recurring basis by level within the fair value hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ Quoted Price in ​ Significant ​ ​ ​ ​ Active Market ​ Other ​ Unobservable ​ ​ for Identical Observable Inputs ​ ​ Assets (Level 1) Inputs (Level 2) ​ (Level 3) ​ RMB RMB RMB Recurring ​ As of December 31, 2019: ​ ​ ​ ​ ​ ​ Short-term investments: ​ ​ ​ ​ ​ ​ Debt securities: ​ ​ ​ ​ ​ ​ Trading ​ — ​ 795,849 ​ — Equity securities: ​ ​ ​ ​ ​ ​ Marketable ​ 11,925 ​ — ​ — ​ ​ 11,925 795,849 —
Schedule of fair value instruments on unobservable input reconciliation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fair Value Measurements ​ ​ Quoted Price in ​ Significant ​ ​ ​ ​ Active Market ​ Other ​ Unobservable ​ ​ for Identical ​ Observable ​ Inputs ​ ​ Assets (Level 1) ​ Inputs (Level 2) ​ (Level 3) ​ RMB RMB RMB As of December 31, 2018: ​ ​ ​ ​ ​ Short term investments: ​ ​ ​ ​ ​ Debt securities: ​ ​ ​ ​ ​ ​ Held-to-maturity ​ — ​ 7,630,689 — As of December 31, 2019: ​ ​ ​ ​ ​ Short-term investments: ​ ​ ​ ​ ​ ​ Debt securities: ​ ​ ​ ​ ​ ​ Held-to-maturity ​ — ​ 34,481,053 — Convertible bonds ​ — ​ 8,037,280 —

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Dec. 31, 2019
Revenues
Schedule of revenues	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 2018 2019 ​ 2019 ​ RMB ​ RMB RMB US$ Online marketplace services ​ ​ ​ ​ ​ ​ ​ ​ Online marketing services 1,209,275 ​ 11,515,575 26,813,641 3,851,539 Transaction services 531,416 ​ 1,604,415 3,328,245 478,072 Merchandise sales 3,385 ​ — — — ​ 1,744,076 ​ 13,119,990 30,141,886 4,329,611
Schedule of information about contract liabilities, comprising customer advances, deferred revenues and portions of Payables to merchants	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of ​ ​ December 31, 2018 ​ December 31, 2019 ​ December 31, 2019 ​ RMB RMB US$ Customer advances and deferred revenues 191,482 605,970 87,042 Payable to merchants 72,939 ​ 116,557 ​ 16,742

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Share-Based Compensation
Schedule of assumptions used to estimate the fair value of options	​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 2018 2019 Risk-free interest rates ​ 2.26%-2.57% ​ 2.97%-3.13% ​ 1.50%-2.90% Expected volatility ​ 48.08%-49.35% ​ 46.23%-48.63% ​ 43.52%-57.59% Expected dividend yield ​ 0% ​ 0% ​ 0% Exercise multiple ​ 2.80 ​ 2.80 2.80 Post-vesting forfeit rate ​ 0% ​ 0% ​ 0% Fair value of underlying Ordinary Shares ​ $0.0858-$0.5359 ​ $1.5146-$5.7400 ​ $4.8550-$8.9875 Fair value of share option ​ $0.0808-$0.5302 ​ $1.5091-$5.7335 ​ $4.8485-$8.9810
Schedule of recognized share-based compensation expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended ​ ​ December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ 2019 ​ RMB ​ RMB RMB US$ Costs of revenues ​ 796 ​ 3,488 ​ 23,835 3,424 Sales and marketing expenses ​ 1,675 ​ 405,805 ​ 860,862 123,655 General and administrative expenses i) / ii) ​ 108,141 ​ 6,296,186 ​ 786,641 112,994 Research and development ​ 5,893 ​ 136,094 ​ 886,368 127,319 ​ ​ 116,505 ​ 6,841,573 ​ 2,557,706 367,392 i) For the year ended December 31, 2017, the Company recorded RMB103,125, in share-based compensation expenses in connection with the repurchase of Class B ordinary shares from the Founder. No such transaction took place during the years ended December 31, 2018 and 2019. ii) In April 2018, the Company issued 254,473,500 Class A ordinary shares to a company controlled by the Founder at the par value of US$0.000005 per share pursuant to a shareholders’ resolution. The difference between the par value and estimated fair value of ordinary shares on the grant date was recorded as a one-time share-based compensation expense of RMB5,953,717 in general and administration expenses. No such transaction took place during the years ended December 31, 2017 and 2019.
RSU
Share-Based Compensation
Summary of Group's share-based compensation activities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ average ​ ​ Number ​ grant date ​ ​ of RSUs ​ fair value ​ ​ ​ ​ US$ Outstanding as of January 1, 2018 — — Granted 8,295,240 6.2519 Outstanding as of December 31, 2018 ​ 8,295,240 ​ 6.2519 Granted ​ 36,409,188 ​ 6.7698 Vested ​ (567,636) ​ 6.9225 Forfeited ​ (2,761,724) ​ 6.4514 Outstanding as of December 31, 2019 41,375,068 6.6855
Stock option
Share-Based Compensation
Summary of Group's share-based compensation activities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ Weighted ​ ​ ​ ​ Weighted ​ average ​ ​ ​ average ​ ​ ​ ​ average ​ grant ​ Aggregate ​ remaining ​ ​ Number of ​ exercise ​ date fair ​ intrinsic ​ contractual ​ share options price value value term ​ ​ ​ US$ US$ US$ ​ Years Outstanding as of January 1,2017 ​ 203,733,060 0.0065 0.0301 ​ 10,390 ​ 9.25 Granted ​ 78,560,000 0.0065 0.1736 ​ ​ Forfeited ​ (9,850,200) 0.0065 0.0544 ​ ​ Outstanding as of December 31, 2017 ​ 272,442,860 ​ 0.0065 ​ 0.0706 ​ 144,258 ​ 8.57 Granted 359,390,000 0.0065 3.6289 ​ ​ Forfeited ​ (2,240,000) 0.0065 2.5006 ​ ​ ​ ​ Outstanding as of December 31, 2018 629,592,860 0.0065 2.0931 3,527,924 8.64 Granted 76,665,380 0.0065 7.7632 ​ ​ Forfeited (7,937,140) 0.0065 5.7059 ​ ​ Outstanding as of December 31, 2019 698,321,100 0.0065 2.6745 6,598,087 7.83 Vested and expected to vest as of December 31, 2019 698,321,100 0.0065 2.6745 6,598,087 7.83 Exercisable as of December 31,2019 298,464,265 0.0065 1.1083 2,820,040 7.01 ​

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Taxes
Schedule of Group's loss before income taxes	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Non-PRC ​ (108,086) ​ (7,083,904) (2,741,219) (393,751) PRC ​ (417,029) ​ (3,133,221) (4,226,384) (607,083) ​ ​ (525,115) ​ (10,217,125) (6,967,603) (1,000,834)
Schedule of reconciliations of the income tax expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Loss before income tax expense (525,115) ​ (10,217,125) (6,967,603) (1,000,834) ​ PRC statutory tax rate 25 % 25 % 25 % 25 % Income tax benefits at PRC statutory tax rate (131,279) ​ (2,554,281) (1,741,901) (250,208) ​ International tax rate differential 27,074 ​ 1,779,100 735,028 105,580 ​ Preferential tax rate ​ — ​ 197,828 ​ 358,796 ​ 51,538 ​ Non-deductible expenses 6,890 ​ 36,726 (5,980) (859) ​ Non-taxable income (11,962) ​ (20,973) (61,151) (8,784) ​ Loss not recognized ​ 22,747 ​ — ​ — ​ — ​ Deferred tax items tax rate differential ​ — ​ (34,236) ​ (570,382) ​ (81,930) ​ Additional deduction of research and development expenses ​ — ​ (22,672) ​ (67,628) ​ (9,714) ​ Change in valuation allowance 86,530 ​ 618,508 1,353,218 194,377 ​ Income tax expenses — ​ — — — ​
Schedule of significant components of the Group's deferred tax assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ US$ Deferred tax assets ​ ​ ​ ​ ​ ​ Tax losses carried forward ​ 343,809 1,840,246 264,335 Carryforwards of non-deductible advertising expenses and donations ​ 424,883 ​ 251,829 ​ 36,173 Others ​ 13,276 ​ 43,111 ​ 6,193 Less: valuation allowance ​ (781,968) (2,135,186) (306,701) Deferred tax assets, net ​ — — — ​

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2019
Related Party Transactions
Schedule of relationship with related parties	​ Names of related parties Relationship with the Group Tencent and its affiliates (“Tencent Group”) ​ A shareholder of the Company Toshare Group Holding Limited (1) ​ Company controlled by the Founder Suzhou Lebei Network Technology Co., Ltd (2) ​ Company controlled by one of the directors of the Company Ningbo Hexin Equity Investment Partnership ​ Company controlled by one of the executive officers of the Company (1) Toshare Group Holding Limited was no longer a related party of the Company since September 2019. (2) Suzhou Lebei Network Technology Co., Ltd was no longer a related party of the Company since June 2018.
Schedule of significant related party transactions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Services received from: ​ ​ ​ ​ ​ ​ ​ ​ Tencent Group 516,014 ​ 1,266,362 2,298,074 330,098 Suzhou Lebei Network Technology Co., Ltd 2,444 ​ — — —
Schedule of related party balances	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ 2019 ​ RMB RMB US$ Accounts due from related parties: Current: Tencent Group* 1,018,963 1,905,793 273,750 Ningbo Hexin Equity Investment Partnership ** — 459,632 66,022 Accounts due to related parties: ​ ​ ​ Current: ​ ​ ​ ​ ​ ​ Toshare Group Holding Limited 19,966 — — Tencent Group 458,147 1,502,892 215,877 * The balance represents receivables due from the online payment platform operated by Tencent Group. ** The balance represents a loan to Ningbo Hexin Equity Investment Partnership, an entity controlled by one of the executive officers of the Company.

Loss Per Share (Tables)

Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Loss Per Share
Schedule of computation of basic and diluted net loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the year ended December 31, ​ 2017 2018 2019 2019 ​ ​ RMB ​ RMB ​ RMB ​ US$ Numerator: ​ ​ ​ ​ ​ ​ ​ ​ Net loss ​ (525,115) ​ (10,217,125) (6,967,603) (1,000,834) Deemed distribution to certain holders of convertible preferred shares ​ — ​ (80,496) — — Contribution from certain holder of convertible preferred shares ​ 26,413 ​ — — — Net loss attributable to ordinary shareholders ​ (498,702) ​ (10,297,621) (6,967,603) (1,000,834) ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator (in thousands of shares): ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average number of ordinary shares outstanding – basic and diluted ​ 1,764,799 ​ 2,968,320 4,627,278 4,627,278 ​ ​ ​ ​ ​ ​ ​ ​ ​ Loss per share – basic and diluted ​ (0.28) ​ (3.47) (1.51) (0.22)

Condensed Financial Informati_2

Condensed Financial Information of the Company (Tables)	12 Months Ended
	Dec. 31, 2019
Condensed Financial Information of the Company
Condensed balance sheets of parent company	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of December 31, ​ ​ 2018 ​ 2019 ​ RMB RMB US$ ASSETS ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current assets ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ 5,541,746 661,714 95,049 Short-term investments ​ 6,260,689 ​ 6,157,221 ​ 884,429 Prepayments and other current assets ​ 18,789 17,906 2,572 Total current assets ​ 11,821,224 6,836,841 982,050 Non-current assets ​ ​ ​ ​ ​ ​ Intangible asset ​ 2,579,338 ​ 1,994,292 ​ 286,462 Investments in subsidiaries, the VIE and subsidiaries of the VIE ​ 4,440,777 21,053,370 3,024,127 Total non-current assets ​ 7,020,115 23,047,662 3,310,589 Total assets ​ 18,841,339 29,884,503 4,292,639 ​ ​ ​ ​ ​ ​ ​ LIABILITIES AND SHAREHOLDERS' EQUITY ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Current liabilities ​ ​ Accrued expenses and other liabilities ​ 18,745 23,566 3,385 Total current liabilities ​ 18,745 23,566 3,385 ​ ​ ​ ​ ​ ​ ​ Convertible bonds ​ — 5,206,682 747,893 Other non-current liabilities ​ — 7,389 1,061 Total non-current liabilities ​ — 5,214,071 748,954 Total liabilities ​ 18,745 5,237,637 752,339 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Shareholders’ equity Class A ordinary shares (US$ 0.000005 par value; 77,300,000,000 shares authorized, 2,381,240,988 issued and outstanding as of December 31, 2018; 77,300,000,000 shares authorized, 2,575,580,988 issued and outstanding as of December 31, 2019) 78 84 12 Class B ordinary shares (US$ 0.000005 par value; 2,200,000,000 authorized, 2,074,447,700 issued and outstanding as of December 31, 2018 and 2019) 64 64 9 Additional paid-in capital 29,114,527 41,493,949 5,960,233 Accumulated other comprehensive income 1,035,783 1,448,230 208,025 Accumulated deficits (11,327,858) (18,295,461) (2,627,979) Total shareholders' equity 18,822,594 24,646,866 3,540,300 Total liabilities and shareholders’ equity 18,841,339 29,884,503 4,292,639
Condensed statements of comprehensive income of parent company	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ 2017 ​ 2018 ​ 2019 ​ RMB ​ RMB RMB US$ Costs of revenues ​ ​ ​ ​ ​ ​ ​ ​ Costs of online marketplace services ​ — ​ (491,069) ​ (619,733) ​ (89,019) Total costs of revenues ​ — ​ (491,069) ​ (619,733) ​ (89,019) Sales and marketing expenses ​ — ​ (4,106) ​ (47,746) ​ (6,858) General and administrative expenses (165) ​ (4,101) (3,245) (466) Total operating expenses (165) ​ (8,207) (50,991) (7,324) Operating loss (165) ​ (499,276) (670,724) (96,343) Interest income 8,264 ​ 207,597 318,166 45,702 Interest expense ​ — ​ — ​ (144,132) ​ (20,703) Foreign exchange gain — ​ 113 — — Other loss — ​ — (31) (4) Share of losses from subsidiaries, the VIE and subsidiaries of the VIE (533,214) ​ (9,925,559) (6,470,882) (929,484) Loss before income tax (525,115) ​ (10,217,125) (6,967,603) (1,000,832) Income tax expenses ​ — ​ — ​ — ​ — Net loss (525,115) ​ (10,217,125) (6,967,603) (1,000,832) ​ ​ ​ ​ ​ ​ ​ ​ ​ Other comprehensive income, net of tax of nil ​ Foreign currency translation difference, net of tax of nil (47,681) ​ 1,058,884 412,447 59,244 Comprehensive loss (572,796) ​ (9,158,241) (6,555,156) (941,588)
Condensed statement of cash flows of parent company	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the years ended December 31, ​ ​ 2017 ​ 2018 ​ 2019 ​ RMB ​ RMB RMB US$ Net cash generated from operating activities ​ 2,753 ​ 110,724 259,409 37,262 Cash flows from investing activities: ​ ​ ​ Proceeds from sales of short-term investments ​ — ​ — ​ 6,049,590 868,969 Cash given to purchase of short-term investments ​ — ​ (6,146,370) ​ (5,998,024) ​ (861,562) Cash given to subsidiaries, the VIE and subsidiaries of the VIE ​ (1,058,908) ​ (6,749,831) ​ (20,293,132) (2,914,926) Net cash used in investing activities ​ (1,058,908) ​ (12,896,201) ​ (20,241,566) (2,907,519) Cash flows from financing activities: ​ ​ ​ ​ ​ ​ Proceeds from initial public offering ​ — ​ 11,879,944 — — Costs incurred for the initial public offering costs ​ — ​ (356,313) ​ — ​ — Proceeds from follow-on offering ​ — ​ — 8,194,597 1,177,080 Costs incurred for the issuance costs of follow-on offering ​ — ​ — ​ (200,769) ​ (28,839) Proceeds from issuance of convertible bonds ​ — ​ — 7,073,101 1,015,987 Costs incurred for the issuance of convertible bonds ​ — ​ — ​ (106,344) ​ (15,275) Proceeds from issuance of convertible preferred shares ​ 1,446,906 ​ 5,824,568 ​ — ​ — Costs incurred for the issuance at convertible preferred shares ​ (15,369) ​ (3,842) ​ — ​ — Repurchase of Class B Ordinary Shares ​ (32,677) ​ — — — Net cash generated from financing activities ​ 1,398,860 ​ 17,344,357 14,960,585 2,148,953 Exchange rate effect on cash, cash equivalents and restricted cash ​ (47,820) ​ 319,221 141,540 20,331 Net increase/(decrease) in cash, cash equivalents and restricted cash ​ 294,885 ​ 4,878,101 (4,880,032) (700,973) Cash, cash equivalents and restricted cash at beginning of year ​ 368,760 ​ 663,645 5,541,746 796,022 Cash, cash equivalents and restricted cash at end of year ​ 663,645 ​ 5,541,746 661,714 95,049

Organization - Ownership intere

Organization - Ownership interest (Details)	1 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2019
Hangzhou Aimi or VIE
Major subsidiaries, consolidated VIE and the subsidiary of the VIE
Percentage of direct or indirect ownership in VIEs		100.00%
Shanghai Xunmeng
Major subsidiaries, consolidated VIE and the subsidiary of the VIE
Percentage of direct or indirect ownership in VIEs	100.00%	100.00%
Walnut HK
Major subsidiaries, consolidated VIE and the subsidiary of the VIE
Percentage of ownership by the Company		100.00%
Hangzhou Weimi or WFOE
Major subsidiaries, consolidated VIE and the subsidiary of the VIE
Percentage of ownership by the Company		100.00%

Organization - The VIE agreemen

Organization - The VIE agreements (Details) - Exclusive Consulting and Services Agreement	12 Months Ended
	Dec. 31, 2019
The VIE agreements
Term of agreement (in years)	10 years
Automatic extended term of agreement (in years)	10 years
Notice period for termination of agreement (in months)	3 months

Organization - Financial inform

Organization - Financial information for the VIE (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2019CNY (¥)
Current assets
Cash and cash equivalents	$ 828,548		¥ 14,160,322	¥ 3,058,152	¥ 5,768,186
Restricted cash	3,961,285		16,379,364	9,370,849	27,577,671
Receivables from online payment	150,963		247,586		1,050,974
Short-term investments	5,068,923		7,630,689		35,288,827
Amounts due from related parties (i)	339,787		1,019,033		2,365,528
Prepayments and other current assets	136,499		953,989		950,277
Total current assets	10,486,005		40,390,983		73,001,463
Non-current assets
Property, equipment and software, net	5,928		29,075		41,273
Right-of-use assets	74,289				517,188
Other non-current assets	72,269		182,667		503,120
Total non-current assets	438,948		2,791,080		3,055,873
Total Assets	10,924,953		43,182,063		76,057,336
Current liabilities
Amounts due to related parties	215,877		478,113		1,502,892
Payable to merchants	4,298,671		17,275,934		29,926,488
Accrued expenses and other liabilities	700,547		2,225,667		4,877,062
Merchant deposits	1,126,277		4,188,273		7,840,912
Short-term borrowings	129,097				898,748
Current portion of lease liabilities	16,624				115,734
Total current liabilities	6,574,135		24,359,469		45,767,806
Non-Current portion of Lease liabilities	61,564				428,593
Total non-current liabilities	810,518				5,642,664
Total liabilities	7,384,653		24,359,469		51,410,470
Consolidated statement of income (loss)
Net revenues	4,329,611	¥ 30,141,886	13,119,990	1,744,076
Net loss	(1,000,834)	(6,967,603)	(10,217,125)	(525,115)
Consolidated statement of cashflows
Net cash generated from operating activities	2,128,900	14,820,976	7,767,927	9,686,328
Net cash generated from /(used in) investing activities	(4,067,867)	(28,319,678)	(7,548,509)	71,651
Net cash provided by financing activities	2,277,390	15,854,731	17,344,357	1,398,860
Net increase in cash, cash equivalents and restricted cash	403,082	¥ 2,806,171	18,110,685	11,109,158
Restricted cash	3,961,285		16,379,364	¥ 9,370,849	27,577,671
Consolidated VIE
Current liabilities
Amounts due to related parties	215,877		458,147		1,502,892
Payable to merchants	4,259,994		17,275,934		29,657,227
Accrued expenses and other liabilities	491,358		1,500,951		3,420,728
Merchant deposits	1,126,277		4,188,273		7,840,912
Short-term borrowings	129,097		0		898,748
Current portion of lease liabilities	13,003		0		90,523
Non-Current portion of Lease liabilities	$ 54,968		¥ 0		382,673
Consolidated VIE | Consolidated revenues
Financial information for the VIE
Concentration (as a percent)	58.50%	58.50%	77.30%	100.00%
Consolidated VIE | Consolidated total assets
Financial information for the VIE
Concentration (as a percent)	54.10%	54.10%	53.10%
Consolidated VIE | Consolidated total liabilities
Financial information for the VIE
Concentration (as a percent)	86.40%	86.40%	96.90%
Reportable legal entity | Consolidated VIE
Current assets
Cash and cash equivalents	$ 404,622		¥ 3,529,316		2,816,894
Restricted cash	3,954,264		16,379,364		27,528,793
Receivables from online payment	150,963		247,586		1,050,974
Short-term investments	942,381		1,300,000		6,560,665
Amounts due from related parties (i)	339,031		1,018,963		2,360,267
Amounts due from Group companies	479,369		565,101		3,337,273
Prepayments and other current assets	42,428		441,590		295,377
Total current assets	6,313,058		23,481,920		43,950,243
Non-current assets
Property, equipment and software, net	3,982		16,578		27,719
Right-of-use assets	65,053				452,883
Other non-current assets	8,662				60,306
Total non-current assets	77,697		16,578		540,908
Total Assets	6,390,755		23,498,498		44,491,151
Current liabilities
Amounts due to Group companies	774,779		1,575,534		5,393,858
Amounts due to related parties	215,877		458,147		1,502,892
Customer advances and deferred revenues	87,042		190,382		605,969
Payable to merchants	4,259,994		17,275,934		29,657,227
Accrued expenses and other liabilities	491,358		1,500,951		3,420,728
Merchant deposits	1,126,277		4,188,273		7,840,912
Short-term borrowings	129,097				898,748
Current portion of lease liabilities	13,003				90,523
Total current liabilities	7,097,427		25,189,221		49,410,857
Non-Current portion of Lease liabilities	54,968				382,673
Total non-current liabilities	54,968				382,673
Total liabilities	7,152,395		25,189,221		49,793,530
Consolidated statement of income (loss)
Net revenues	2,854,913	¥ 19,875,332	10,435,289	¥ 1,951,646
Net loss	(518,782)	(3,611,656)	(1,552,789)	(8,924)
Consolidated statement of cashflows
Net cash generated from operating activities	1,600,099	11,139,572	8,984,498	10,391,383
Net cash generated from /(used in) investing activities	(753,978)	(5,249,046)	(1,147,101)	88,404
Net cash provided by financing activities	653,061	4,546,481	507,767	200,000
Net increase in cash, cash equivalents and restricted cash	1,499,182	10,437,007	8,345,164	10,679,787
Restricted cash	3,954,264		16,379,364		¥ 27,528,793
Reportable legal entity | Group companies | Consolidated VIE
Consolidated statement of income (loss)
Net revenues	322,392	2,244,429	298,415	207,570
Reportable legal entity | External | Consolidated VIE
Consolidated statement of income (loss)
Net revenues	$ 2,532,521	¥ 17,630,903	¥ 10,136,874	¥ 1,744,076

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Convenience translation (Details)	Dec. 31, 2019
US$
Convenience translation rate (USD to RMB)	1
RMB
Convenience translation rate (USD to RMB)	6.9618

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Property, equipment and software (Details)	12 Months Ended
	Dec. 31, 2019
Computer and office equipment
Property, Equipment and Software, Net
Estimated useful life	3 years
Purchased software | Minimum
Property, Equipment and Software, Net
Estimated useful life	3 years
Purchased software | Maximum
Property, Equipment and Software, Net
Estimated useful life	5 years

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Impairment of long-lived assets other than goodwill and Advertising expenditures (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Summary of Significant Accounting Policies
Impairment of any long-lived assets		¥ 0	¥ 0	¥ 0
Advertising expenditures recognized in sales and marketing expenses	$ 3,715,673	¥ 25,867,772	¥ 12,867,833	¥ 1,259,610

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Cumulative effects of changes (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Jan. 01, 2019USD ($)	Jan. 01, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Assets:
Prepayments and other current assets	$ 136,499	¥ 950,277			¥ 953,989
Right-of-use assets	74,289	517,188
Liabilities:
Current portion of lease liabilities	16,624	115,734
Non-Current portion of Lease liabilities	$ 61,564	¥ 428,593
Accounting Standards Update 2016-02 [Member]
Assets:
Prepayments and other current assets			$ 136,634	¥ 951,221
Right-of-use assets			31,820	221,521
Liabilities:
Current portion of lease liabilities			7,926	55,180
Non-Current portion of Lease liabilities			25,091	174,681
Accrued expenses and other liabilities			318,101	2,214,559
Deferred rent			1,596	11,108
Prepaid Rent			$ 398	¥ 2,768
Previously Reported [Member]
Assets:
Prepayments and other current assets					953,989
Liabilities:
Accrued expenses and other liabilities					2,225,667
Restatement Adjustment [Member]
Assets:
Prepayments and other current assets					(2,768)
Right-of-use assets					221,521
Liabilities:
Current portion of lease liabilities					55,180
Non-Current portion of Lease liabilities					174,681
Accrued expenses and other liabilities					¥ (11,108)

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Segment reporting (Details)	12 Months Ended
	Dec. 31, 2019segment
Summary of Significant Accounting Policies
Number of reportable segment	1

Concentration of Risks (Details

Concentration of Risks (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Concentration of Risks
Minimum number of years for economic reform policies pursuing by PRC government	20 years
Percentage of appreciation (depreciation) of US dollar against RMB	1.60%	5.00%	(5.80%)

Short-term Investments - Classi

Short-term Investments - Classification (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Debt securities:
Held-to-maturity	$ 4,952,893	¥ 34,481,053	¥ 7,630,689
Trading	114,317	795,849
Equity securities:
Marketable	1,713	11,925
Short-term Investments, Total	$ 5,068,923	¥ 35,288,827	¥ 7,630,689

Short-term Investments - Additi

Short-term Investments - Additional information (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2019CNY (¥)
Short-term Investments
Gross unrecognized holding gain of the held-to-maturity debt securities			¥ 0		¥ 0
Gross unrecognized holding loss of the held-to-maturity debt securities			0		0
Cost of trading debt securities	$ 114,317		0		795,849
Gross unrealized gain (loss) on debt trading securities		¥ 0	0
Interest income on short-term investments	71,863	500,298	115,737	¥ 12,483
Marketable Securities	3,361		0		¥ 23,398
Unrealized loss for marketable equity securities	1,648	11,473
Realized loss for marketable equity securities	$ 781	¥ 5,435	¥ 0	¥ 0

Prepayments and Other Current_3

Prepayments and Other Current Assets (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Prepayments and Other Current Assets
Prepayments	$ 92,673	¥ 645,169	¥ 667,113
Interest receivables	21,014	146,294	101,062
VAT recoverable	14,713	102,426	63,005
Rental and other deposits	1,732	12,060	64,902
Loan to a third party			35,000
Staff advances	577	4,020	7,868
Payments made on behalf of merchants	3,930	27,360	11,105
Provision for payments made on behalf of merchants	(2,159)	(15,032)	(3,249)
Others	4,019	27,980	7,183
Total	$ 136,499	¥ 950,277	¥ 953,989

Property, Equipment and Softw_2

Property, Equipment and Software, Net (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Property, Equipment and Software, Net
At cost	$ 9,761	¥ 67,955	¥ 37,802
Less: accumulated depreciation	(3,833)	(26,682)	(8,727)
Property, equipment and software, net	5,928	41,273	29,075
Computer, office equipment and purchased software
Property, Equipment and Software, Net
At cost	7,057	49,129	27,148
Leasehold improvement
Property, Equipment and Software, Net
At cost	$ 2,704	¥ 18,826	¥ 10,654

Property, Equipment and Softw_3

Property, Equipment and Software, Net - Depreciation expenses (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Property, Equipment and Software, Net
Depreciation expenses	$ 2,600	¥ 18,098	¥ 5,934	¥ 2,265
Costs of revenues
Property, Equipment and Software, Net
Depreciation expenses	518	3,603	1,291	553
Sales and marketing expenses
Property, Equipment and Software, Net
Depreciation expenses	347	2,415	805	546
General and administrative expenses
Property, Equipment and Software, Net
Depreciation expenses	273	1,901	1,074	181
Research and development expenses
Property, Equipment and Software, Net
Depreciation expenses	$ 1,462	¥ 10,179	¥ 2,764	¥ 985

Intangible Asset (Details)

Intangible Asset (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Intangible Asset
Beginning balance		¥ 2,579,338
Addition			¥ 2,852,370
Amortization	$ (89,019)	(619,733)	(491,069)
Foreign currency translation difference		34,687	218,037
Ending balance		1,994,292	2,579,338
Impairment charges		¥ 0	0
Convertible preferred stock
Intangible Asset
Addition			¥ 2,852,000

Intangible Asset -Estimated ann

Intangible Asset -Estimated annual amortization expense (Details) - Dec. 31, 2019 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Intangible Asset
2020	$ 90,384	¥ 629,233
2021	90,137	627,514
2022	90,137	627,514
2023	$ 15,805	¥ 110,031

Leases - Maturity analysis of t

Leases - Maturity analysis of the Company's (Details) - Dec. 31, 2019 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020	$ 20,405	¥ 142,058
2021	21,579	150,231
2022	18,491	128,731
2023	13,588	94,598
2024 and after	14,013	97,558
Total undiscounted cash flows	88,076	613,176
Less: imputed interest	(9,888)	(68,849)
Present value of lease liabilities	$ 78,188	¥ 544,327

Leases - Other supplemental (De

Leases - Other supplemental (Details) - 12 months ended Dec. 31, 2019 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Leases
Operating cash flows for operating leases	$ 10,935	¥ 76,130
ROU assets obtained in exchange for new operating lease liabilities	$ 57,836	¥ 402,646

Leases - Additional Information

Leases - Additional Information (Details) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019CNY (¥)
Leases
Operating Lease, Cost	¥ 94,929
Short-term Lease, Cost	¥ 34,255
Weighted average remaining lease terms of the right-of-use assets	4 years 4 months 13 days
Weighted average incremental borrowing rate	5.36%

Other Non-Current Asset - Addit

Other Non-Current Asset - Additional Information (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Schedule of Investments [Line Items]
Share of profits or losses of the equity investees	$ 4,119	¥ 28,676
Limited partnership funds
Schedule of Investments [Line Items]
Carrying amount for the investments	62,290		¥ 433,649	¥ 182,667
Equity Method Investments not Considered as Material			¥ 0
Share of profits or losses of the equity investees	$ 4,119	¥ 28,676

Accrued Expenses and Other Li_3

Accrued Expenses and Other Liabilities (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Accrued Expenses and Other Liabilities
Payroll payable	$ 152,436	¥ 1,061,228	¥ 389,615
Accrued expenses	391,748	2,727,273	1,371,483
VAT and other tax payable	150,219	1,045,796	436,495
Others	6,144	42,765	28,074
Total	$ 700,547	¥ 4,877,062	¥ 2,225,667

Short-term Borrowings (Details)

Short-term Borrowings (Details) - 12 months ended Dec. 31, 2019 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Short-term Debt [Line Items]
Short term borrowings	$ 128,850	¥ 897,022
Short-term investments collateralized by bank wealth management products		923,800
Interest expense	$ 248	¥ 1,726
Minimum
Short-term Debt [Line Items]
Annual interest rate		2.70%
Maximum
Short-term Debt [Line Items]
Annual interest rate		3.00%

Convertible Bonds (Details)

Convertible Bonds (Details)	Sep. 27, 2019USD ($)$ / shares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2019CNY (¥)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018$ / shares
Convertible senior notes
Debt Instrument [Line Items]
Principal amount	$ 1,000,000,000
Coupon Rate	0.00%
Debt instrument purchasers over-allotment option	$ 125,000,000
Principal amount per conversion rate	$ 1,000,000
Trading days | ¥			40
Initial conversion rate (ADS per US$1,000 principal amount)	23.4680
Initial conversion price (per ADS) | $ / shares	$ 42.61
Effective interest rate	11.15%
Gross proceeds from the issuance of the Notes		$ 1,000,000
Debt issuance costs		15,680,000
Principal amount of the liability		1,000,000,000
Unamortized debt discount		253,651,000
Net carrying amount of the liability | ¥				¥ 5,206,682,000
Carrying amount of the equity component		258,429,000
Amortization of the discount		$ 20,703,000	¥ 144,132,000
Principal amount over a remaining period		2 years 9 months	2 years 9 months
Convertible senior notes | Redemption one
Debt Instrument [Line Items]
Ordinary shares, par value | $ / shares		$ 0.000005
Trading days | ¥			20
Consecutive trading day | ¥			30
Percentage of conversion price		130.00%	130.00%
Convertible senior notes | Redemption two
Debt Instrument [Line Items]
Principal amount		$ 1,000,000
Trading days | ¥			5
Consecutive trading day | ¥			10
Percentage of conversion price		98.00%	98.00%
Class A ordinary shares
Debt Instrument [Line Items]
Ordinary shares, par value | $ / shares		$ 0.000005			$ 0.000005

Convertible Preferred Shares -

Convertible Preferred Shares - Issuances of convertible preferred shares (Details)	12 Months Ended	24 Months Ended
	Dec. 31, 2019$ / sharesshares	Dec. 31, 2018shares
Convertible Preferred Shares
Conversion ratio for each Convertible Preferred Share into each Ordinary Share	1
Series A1 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.0093
Number of Shares	71,849,380
Series A2 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.0336
Number of Shares	238,419,800
Series B1 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.1576
Number of Shares	211,588,720
Series B2 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.1576
Number of Shares	27,781,280
Series B3 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.1576
Number of Shares	145,978,540
Series B4 Convertible Preferred Shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.1710
Number of Shares	292,414,780
Series C1 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.3545
Number of Shares	56,430,180
C2 Convertible Preferred Shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.3985
Number of Shares	238,260,780
Series C3 convertible preferred shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 0.4139
Number of Shares	241,604,260
Series D Convertible Preferred Shares
Convertible Preferred Shares
Original Issuance Price per Share | $ / shares	$ 2.4832
Number of Shares	551,174,340
Stock split ratio of Convertible Preferred Shares	0.05
Conversion of stock, shares issued		0

Convertible Preferred Shares _2

Convertible Preferred Shares - Liquidation Prefrence (Details)	12 Months Ended
	Dec. 31, 2019
Convertible Preferred Shares
Liquidation preference, percentage of issue price	100.00%
Compound annual rate	8.00%

Convertible Preferred Shares _3

Convertible Preferred Shares - Accounting for Convertible Preferred Shares (Details) ¥ in Thousands, $ in Thousands	1 Months Ended			12 Months Ended
	Mar. 31, 2018USD ($)shares	Feb. 28, 2017CNY (¥)shares	Feb. 29, 2016CNY (¥)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018USD ($)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)	Dec. 31, 2016CNY (¥)
Convertible Preferred Shares
Excess of the issuance price paid by investor over fair value encounter as contribution from shareholder							¥ 26,413
Proceeds from issuance of Convertible Preferred Shares						¥ 5,824,568	1,446,906
Increase to fair value of modified Convertible Preferred Shares as deemed dividends				¥ 80,496	$ 11,708	80,496
General and administrative expenses
Convertible Preferred Shares
Share-based compensation expense recognized on repurchase of ordinary shares		¥ 103,125
Series C1 convertible preferred shares
Convertible Preferred Shares
Excess of the issuance price paid by investor over fair value encounter as contribution from shareholder		¥ 26,413
Series B1 convertible preferred shares
Convertible Preferred Shares
Deemed distribution								¥ 12,104
Series B2 convertible preferred shares
Convertible Preferred Shares
Special cash dividend approved			¥ 18,326
Series B1 Convertible Preferred Shares and Series B4 Convertible Preferred Shares
Convertible Preferred Shares
Deemed distribution						¥ 0	¥ 0
Class B ordinary shares
Convertible Preferred Shares
Repurchased and cancellation of Class B ordinary shares | shares		56,430,180
Proceeds from issuance of Convertible Preferred Shares		¥ 137,580
Class B ordinary shares | Accumulated Deficits
Convertible Preferred Shares
Share-based compensation expense recognized on repurchase of ordinary shares		¥ 32,677
Series D Convertible Preferred Shares
Convertible Preferred Shares
Number of shares issued | shares	551,174,340
Proceeds from issuance of Convertible Preferred Shares | $	$ 918,670

Convertible Preferred Shares _4

Convertible Preferred Shares - Convertible Redeemable Preferred (Details) - IPO	1 Months Ended
	Jul. 31, 2018shares
Class B ordinary shares
Convertible Preferred Shares
Number of shares converted	103,690,740
Class A ordinary shares
Convertible Preferred Shares
Number of shares converted	1,971,811,320

Fair Value Measurements - Fair

Fair Value Measurements - Fair value hierarchy (Details) - CNY (¥) ¥ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Measurements
Impairment charge	¥ 0	¥ 0	¥ 10,000
Non-recurring
Fair Value Measurements
Liabilities fair value	0	0
Assets fair value	0	¥ 0
Quoted Price in Active Market for Identical Assets (Level 1) | Recurring | Short-term investments
Fair Value Measurements
Assets fair value	11,925
Quoted Price in Active Market for Identical Assets (Level 1) | Recurring | Marketable equity securities
Fair Value Measurements
Assets fair value	11,925
Significant Other Observable Inputs (Level 2) | Recurring | Short-term investments
Fair Value Measurements
Assets fair value	795,849
Significant Other Observable Inputs (Level 2) | Recurring | Trading debt securities
Fair Value Measurements
Assets fair value	¥ 795,849

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair value measurements (Details) - Significant Other Observable Inputs (Level 2) - CNY (¥) ¥ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Measurements
Held-to-maturity investments	¥ 34,481,053	¥ 7,630,689
Convertible bonds	¥ 8,037,280

Ordinary Shares (Details)

Ordinary Shares (Details) $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 28, 2019USD ($)shares	Sep. 30, 2018USD ($)shares	Dec. 31, 2019Voteshares	Dec. 31, 2018shares
Number of ordinary shares issued				366,943,308
IPO
Total Proceeds, net of issuance cost | $		$ 1,690,696
Follow-on offering
Total Proceeds, net of issuance cost | $	$ 1,181,209
ADSs | IPO
Number of ordinary shares issued		91,735,827
Ordinary shares upon the exercise of the underwriters' over-allotment option		6,135,827
ADSs | Follow-on offering
Number of ordinary shares issued	48,435,000
Class A ordinary shares
Number of Voting Rights Per Each Share | Vote			1
Stock Issued During Period, Shares, Treasury Stock Reissued			42,486,360
Ordinary shares, issued			2,575,580,988	2,381,240,988
Class A ordinary shares | IPO
Number of ordinary shares issued		366,943,308
Class A ordinary shares | Follow-on offering
Number of ordinary shares issued	193,740,000
Class B ordinary shares
Number of Voting Rights Per Each Share | Vote			10
Stock Issued During Period, Shares, Treasury Stock Reissued			1,716,283,460
Ordinary shares, issued			2,074,447,700	2,074,447,700

Revenues (Details)

Revenues (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Revenues
Revenues	$ 4,329,611	¥ 30,141,886	¥ 13,119,990	¥ 1,744,076
Online marketplace services
Revenues
Revenues	4,329,611	30,141,886	13,119,990	1,740,691
Online marketing services
Revenues
Revenues	3,851,539	26,813,641	11,515,575	1,209,275
Transaction services
Revenues
Revenues	$ 478,072	¥ 3,328,245	¥ 1,604,415	531,416
Merchandise sales
Revenues
Revenues				¥ 3,385

Revenues- Contract balances (De

Revenues- Contract balances (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018USD ($)	Dec. 31, 2018CNY (¥)
Revenues
Customer advances and deferred revenues	$ 87,042	¥ 605,970	$ 191,482
Payable to merchants	$ 16,742	116,557	$ 72,939
Customer liability		¥ 219,017		¥ 83,639

Share-Based Compensation - Summ

Share-Based Compensation - Summary (Details) - shares	1 Months Ended	12 Months Ended
	Jul. 31, 2018	Dec. 31, 2019
2015 Plan and the 2018 Plan | Stock Options
Share-Based Compensation
Required Service period (in years)		4 years
Annual vesting percentage		25.00%
Restricted period of holding after exercise (in years)		3 years
Additional implicit service period (in years)		3 years
Vesting period (in years)		7 years
2015 Plan | Stock Options
Share-Based Compensation
Number of shares authorized		581,972,860
Term of the options (in years)		10 years
2018 Plan | RSU
Share-Based Compensation
Number of shares authorized	363,130,400
Term of the options (in years)		4 years
Percentage of annual increase on shares issued	1.00%
Annual vesting percentage		25.00%
Vesting percentage on 2nd anniversary of the grant date		50.00%
Vesting percentage on 3rd and 4th anniversary of the grant date		25.00%

Share-Based Compensation - Su_2

Share-Based Compensation - Summary of Group's option activities (Details) $ / shares in Units, ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)shares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2018CNY (¥)shares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2017CNY (¥)shares	Dec. 31, 2016USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)shares
Weighted average remaining contractual term
Fair value of vested options	$ 322,191	¥ 2,243,028		¥ 45,979		¥ 13,525
Unrecognized share-based compensation expense relating to unvested options	$ 1,435,609							¥ 9,994,423
Weighted-average period for recognition of share-based compensation expense relating to unvested options	4 years 9 months 29 days	4 years 9 months 29 days
2015 Plan and the 2018 Plan
Number of share options
Outstanding at beginning of the year (in shares) | shares	629,592,860	629,592,860	272,442,860	272,442,860	203,733,060	203,733,060
Granted (in shares) | shares	76,665,380	76,665,380	359,390,000	359,390,000	78,560,000	78,560,000
Forfeited (in shares) | shares	(7,937,140)	(7,937,140)	(2,240,000)	(2,240,000)	(9,850,200)	(9,850,200)
Outstanding at end of the year (in shares) | shares	698,321,100	698,321,100	629,592,860	629,592,860	272,442,860	272,442,860	203,733,060
Vested and expected to vest at end of the year (in shares) | shares	698,321,100							698,321,100
Exercisable at end of the year (in shares) | shares	298,464,265							298,464,265
Weighted average exercise price
Outstanding at beginning of the year (in dollars per share)	$ 0.0065		$ 0.0065		$ 0.0065
Granted (in dollars per share)	0.0065		0.0065		0.0065
Forfeited (in dollars per share)	0.0065		0.0065		0.0065
Outstanding at end of the year (in dollars per share)	0.0065		0.0065		0.0065		$ 0.0065
Vested and expected to vest at end of the year (in dollars per share)	0.0065
Exercisable at end of the year (in dollars per share)	0.0065
Weighted average grant date fair value
Outstanding at beginning of the year	2.0931		0.0706		0.0301
Granted	7.7632		3.6289		0.1736
Forfeited	5.7059		2.5006		0.0544
Outstanding at end of the year	2.6745		$ 2.0931		$ 0.0706		$ 0.0301
Vested and expected to vest at end of the year	2.6745
Exercisable at end of the year	$ 1.1083
Aggregate intrinsic value
Outstanding at beginning of the year (in dollars) | $	$ 3,527,924		$ 144,258		$ 10,390
Outstanding at end of the year (in dollars) | $	(6,598,087)		$ 3,527,924		$ 144,258		$ 10,390
Vested and expected to vest at end of the year (in dollars) | $	6,598,087
Exercisable at end of the year (in dollars) | $	$ 2,820,040
Weighted average remaining contractual term
Outstanding (in years)	7 years 9 months 29 days	7 years 9 months 29 days	8 years 7 months 20 days	8 years 7 months 20 days	8 years 6 months 25 days	8 years 6 months 25 days	9 years 3 months
Vested and expected to vest at end of the year (in years)	7 years 9 months 29 days	7 years 9 months 29 days
Exercisable at end of the year (in years)	7 years 3 days	7 years 3 days

Share-Based Compensation - Assu

Share-Based Compensation - Assumptions to estimate the fair value of options (Details) - Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-Based Compensation
Risk-free interest rate, minimum (in percent)	1.50%	2.97%	2.26%
Risk-free interest rate, maximum (in percent)	2.90%	3.13%	2.57%
Expected volatility, minimum (in percent)	43.52%	46.23%	48.08%
Expected volatility, maximum (in percent)	57.59%	48.63%	49.35%
Expected dividend yield (in percent)	0.00%	0.00%	0.00%
Exercise multiple	2.80	2.80	2.80
Post-vesting forfeit rate	0.00%	0.00%	0.00%
Fair value of underlying Ordinary Share, minimum (in dollars per share)	$ 4.8550	$ 1.5146	$ 0.0858
Fair value of underlying Ordinary Share, maximum (in dollars per share)	8.9875	5.7400	0.5359
Fair value of share option, minimum	4.8485	1.5091	0.0808
Fair value of share option, maximum	$ 8.9810	$ 5.7335	$ 0.5302

Share-Based Compensation - Su_3

Share-Based Compensation - Summary of RSU activities (Details) $ / shares in Units, ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)shares	Dec. 31, 2018CNY (¥)shares	Dec. 31, 2018$ / shares	Dec. 31, 2019USD ($)$ / shares	Dec. 31, 2019CNY (¥)
Weighted average grand date fair value
Weighted-average period for recognition of share-based compensation expense relating to unvested options	4 years 9 months 29 days	4 years 9 months 29 days
2018 Plan | RSU
Number of RSUs
Outstanding at beginning of the year (in shares) | shares	8,295,240	8,295,240
Granted (in shares) | shares	36,409,188	36,409,188	8,295,240
Vested | shares	(567,636)	(567,636)
Forfeited (in shares) | shares	(2,761,724)	(2,761,724)
Outstanding at end of the year (in shares) | shares	41,375,068	41,375,068	8,295,240
Weighted average grand date fair value
Outstanding at beginning of the year	$ 6.2519
Granted	6.7698			$ 6.2519
Vested	6.9225
Forfeited	6.4514
Outstanding at end of the year	6.6855			6.2519
Weighted average grant date fair value of RSUs granted	$ 6.6855			$ 6.2519	$ 6.6855
Total fair value of RSUs vested during the period	$ 3,889	¥ 27,073	¥ 0
Unrecognized share-based compensation expenses					$ 208,490	¥ 1,451,466
Weighted-average period for recognition of share-based compensation expense relating to unvested options	3 years 4 months 6 days	3 years 4 months 6 days

Share-Based Compensation - Reco

Share-Based Compensation - Recognized share-based compensation expenses (Details) $ / shares in Units, ¥ in Thousands, $ in Thousands	1 Months Ended			12 Months Ended
	Apr. 30, 2018$ / shares	Apr. 30, 2018CNY (¥)shares	Feb. 28, 2017CNY (¥)	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)shares	Dec. 31, 2017CNY (¥)
Recognized share-based compensation expenses
Share-based compensation expense recognized				$ 367,392	¥ 2,557,706	¥ 6,841,573	¥ 116,505
Shares issued | shares						254,473,500
Costs of revenues
Recognized share-based compensation expenses
Share-based compensation expense recognized				3,424	23,835	¥ 3,488	796
Sales and marketing expenses
Recognized share-based compensation expenses
Share-based compensation expense recognized				123,655	860,862	405,805	1,675
General and administrative expenses
Recognized share-based compensation expenses
Share-based compensation expense recognized				112,994	786,641	6,296,186	108,141
Share-based compensation expense recognized on repurchase of ordinary shares			¥ 103,125
General and administrative expenses | A company controlled by the Founder | Class B ordinary shares
Recognized share-based compensation expenses
Share-based compensation expense recognized on repurchase of ordinary shares							103,125
The per share amount of share-based compensation expense | $ / shares	$ 0.000005
General and administrative expenses | A company controlled by the Founder | Class A ordinary shares
Recognized share-based compensation expenses
Share-based compensation expense recognized		¥ 5,953,717			0		0
Shares issued | shares		254,473,500
Research and development expenses
Recognized share-based compensation expenses
Share-based compensation expense recognized				$ 127,319	¥ 886,368	¥ 136,094	¥ 5,893

Income Taxes - Tax rates (Detai

Income Taxes - Tax rates (Details)	Nov. 30, 2018	Apr. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes
Statutory tax rate (as a percent)			25.00%	25.00%	25.00%
Hong Kong
Income Taxes
Statutory tax rate (as a percent)			16.50%
Withholding tax rate (as a percent)			0.00%
PRC
Income Taxes
Statutory tax rate (as a percent)			25.00%
Withholding tax rate (as a percent)			10.00%
Xinzhijiang | PRC
Income Taxes
Preferential tax rate (as a percent)		15.00%
Shanghai Xunmeng | PRC
Income Taxes
Preferential tax rate (as a percent)	15.00%

Income Taxes - Group's loss bef

Income Taxes - Group's loss before income taxes (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Income Taxes
Loss before income tax expenses	$ (1,000,834)	¥ (6,967,603)	¥ (10,217,125)	¥ (525,115)
Non-PRC
Income Taxes
Loss before income tax expenses	(393,751)	(2,741,219)	(7,083,904)	(108,086)
PRC
Income Taxes
Loss before income tax expenses	$ (607,083)	¥ (4,226,384)	¥ (3,133,221)	¥ (417,029)

Income Taxes - Components and r

Income Taxes - Components and reconciliation of the income tax expense (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Income Taxes
Current income tax expenses or benefits	$ 0	¥ 0	¥ 0	¥ 0
Deferred income tax expenses or benefits	0	0	0	0
Reconciliations of the income tax expenses
Loss before income tax expenses	$ (1,000,834)	¥ (6,967,603)	¥ (10,217,125)	¥ (525,115)
PRC statutory tax rate (in percent)	25.00%	25.00%	25.00%	25.00%
Income tax benefits at PRC statutory tax rate	$ (250,208)	¥ (1,741,901)	¥ (2,554,281)	¥ (131,279)
International tax rate differential	105,580	735,028	1,779,100	27,074
Preferential tax rate	51,538	358,796	197,828
Non-deductible expenses	(859)	(5,980)	36,726	6,890
Non-taxable income	(8,784)	(61,151)	(20,973)	(11,962)
Loss not recognized				22,747
Deferred tax items tax rate differential	(81,930)	(570,382)	(34,236)
Additional deduction of research and development expenses	(9,714)	(67,628)	(22,672)
Change in valuation allowance	$ 194,377	¥ 1,353,218	¥ 618,508	¥ 86,530

Income Taxes - Components of de

Income Taxes - Components of deferred tax assets (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Tax losses carried forward	$ 264,335			¥ 1,840,246	¥ 343,809
Carryforwards of non-deductible advertising expenses and donations	36,173			251,829	424,883
Others	6,193			43,111	13,276
Less: valuation allowance	(306,701)			(2,135,186)	(781,968)
Unrecognized tax benefit on interest expense | $	0	$ 0	$ 0
Unrecognized tax benefit on accumulated interest expense | $	0	$ 0
PRC
Taxable losses	$ 1,174,170			8,174,339	1,551,301
Undistributed earnings of subsidiaries | ¥				0	0
Accrued withholding tax on earnings of subsidiaries | ¥				¥ 0	¥ 0
Minimum
Period for extension	5 years
Maximum
Period for extension	10 years

Related Party Transactions - Si

Related Party Transactions - Significant related party transactions (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Tencent Group
Related Party Transactions
Services received from related party	$ 330,098	¥ 2,298,074	¥ 1,266,362	¥ 516,014
Suzhou Lebei Network Technology Co., Ltd
Related Party Transactions
Services received from related party				¥ 2,444

Related Party Transactions - Re

Related Party Transactions - Related party balances (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)
Related Party Transactions
Amounts due from related parties (i)	$ 339,787	¥ 2,365,528	¥ 1,019,033
Amounts due to related parties	215,877	1,502,892	478,113
Tencent Group
Related Party Transactions
Amounts due from related parties (i)	273,750	1,905,793	1,018,963
Amounts due to related parties	215,877	1,502,892	458,147
Ningbo Hexin Equity Investment Partnership
Related Party Transactions
Amounts due from related parties (i)	$ 66,022	¥ 459,632
Toshare Group Holding Limited
Related Party Transactions
Amounts due to related parties			¥ 19,966

Loss Per Share (Details)

Loss Per Share (Details) ¥ / shares in Units, $ / shares in Units, ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)¥ / sharesshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2018CNY (¥)¥ / sharesshares	Dec. 31, 2017CNY (¥)¥ / sharesshares
Numerator:
Net loss	$ (1,000,834)	¥ (6,967,603)		¥ (10,217,125)	¥ (525,115)
Deemed distribution to certain holders of convertible preferred shares		(80,496)	$ (11,708)	(80,496)
Contribution from a holder of convertible preferred shares | ¥					26,413
Net loss attributable to ordinary shareholders	$ (1,000,834)	¥ (6,967,603)		¥ (10,297,621)	¥ (498,702)
Denominator:
Weighted-average number of ordinary shares outstanding-basic and diluted	4,627,278,000	4,627,278,000	2,968,320,000	2,968,320,000	1,764,799,000
Loss per share-basic and diluted | (per share)	$ (0.22)	¥ (1.51)		¥ (3.47)	¥ (0.28)
Shares issued to depository bank	600,000	600,000
Shares settled	567,636	567,636
Escrow Shares Settled	32,364	32,364
Ordinary shares
Denominator:
Shares issued to depository bank	600,000	600,000

Restricted Net Assets (Details)

Restricted Net Assets (Details) - 12 months ended Dec. 31, 2019 ¥ in Thousands, $ in Thousands	USD ($)	CNY (¥)
Restricted Net Assets
Minimum percentage of after tax profit to be allocated to general reserve	10.00%
Limit of general reserve fund as a percentage of registered capital, after which allocations to general reserve fund are no longer required	50.00%
Restricted net assets of Company's PRC subsidiaries, the VIE and subsidiaries of the VIE	$ 1,198,654	¥ 8,344,790

Mainland China Employee Contr_2

Mainland China Employee Contribution Plan (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Mainland China Employee Contribution Plan
Total expenses incurred for government statutory employee benefit plans	$ 48,038	¥ 334,434	¥ 133,699	¥ 30,795

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Dec. 31, 2019USD ($)
Commitments and Contingencies.
Total investment commitments	$ 16,000

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Events - USD ($) $ in Millions	Mar. 31, 2020	Apr. 30, 2020
Convertible bonds
Subsequent Events
Convertible bonds issued		$ 200
convertible bonds interest rate		5.00%
Class A ordinary shares
Subsequent Events
Private placement	$ 1,100
Percent of outstanding shares	2.80%

Condensed Financial Informati_3

Condensed Financial Information of the Company - Balance sheets (Details) $ / shares in Units, ¥ in Thousands, $ in Thousands	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2019CNY (¥)shares	Dec. 31, 2018$ / shares	Dec. 31, 2018CNY (¥)shares	Dec. 31, 2017CNY (¥)shares	Dec. 31, 2016CNY (¥)
Current assets
Cash and cash equivalents	$ 828,548	¥ 5,768,186		¥ 14,160,322	¥ 3,058,152
Short-term investments	5,068,923	35,288,827		7,630,689
Prepayments and other current assets	136,499	950,277		953,989
Total current assets	10,486,005	73,001,463		40,390,983
Non-current assets
Intangible asset	286,462	1,994,292		2,579,338
Total non-current assets	438,948	3,055,873		2,791,080
Total Assets	10,924,953	76,057,336		43,182,063
Current liabilities
Accrued expenses and other liabilities	700,547	4,877,062		2,225,667
Total current liabilities	6,574,135	45,767,806		24,359,469
Convertible bonds	747,893	5,206,682
Other non-current liabilities	1,061	7,389
Total non-current liabilities	810,518	5,642,664
Total liabilities	7,384,653	51,410,470		¥ 24,359,469
Shareholders' equity
Ordinary shares, outstanding				4,455,688,688	1,758,769,820
Shareholders' deficits
Additional paid-in capital	5,960,233	41,493,949		¥ 29,114,527
Accumulated other comprehensive income	208,025	1,448,230		1,035,783
Accumulated deficits	(2,627,979)	(18,295,461)		(11,327,858)
Total shareholders' equity	3,540,300	24,646,866		18,822,594	¥ (991,958)	¥ (426,278)
Total liabilities and shareholders' equity	$ 10,924,953	¥ 76,057,336		¥ 43,182,063
Class A ordinary shares
Shareholders' equity
Ordinary shares, par value | $ / shares	$ 0.000005		$ 0.000005
Ordinary shares, shares authorized	77,300,000,000	77,300,000,000		77,300,000,000
Ordinary shares, issued	2,575,580,988	2,575,580,988		2,381,240,988
Ordinary shares, outstanding	2,575,580,988	2,575,580,988		2,381,240,988
Shareholders' deficits
Common Shares	$ 12	¥ 84		¥ 78
Class B ordinary shares
Shareholders' equity
Ordinary shares, par value | $ / shares	$ 0.000005		0.000005
Ordinary shares, shares authorized	2,200,000,000	2,200,000,000		2,200,000,000
Ordinary shares, issued	2,074,447,700	2,074,447,700		2,074,447,700
Ordinary shares, outstanding	2,074,447,700	2,074,447,700		2,074,447,700
Shareholders' deficits
Common Shares	$ 9	¥ 64		¥ 64
Parent Company | Reportable legal entity
Current assets
Cash and cash equivalents	95,049	661,714		5,541,746
Short-term investments	884,429	6,157,221		6,260,689
Prepayments and other current assets	2,572	17,906		18,789
Total current assets	982,050	6,836,841		11,821,224
Non-current assets
Intangible asset	286,462	1,994,292		2,579,338
Investments in subsidiaries, the VIE and subsidiaries of the VIE	3,024,127	21,053,370		4,440,777
Total non-current assets	3,310,589	23,047,662		7,020,115
Total Assets	4,292,639	29,884,503		18,841,339
Current liabilities
Accrued expenses and other liabilities	3,385	23,566		18,745
Total current liabilities	3,385	23,566		18,745
Convertible bonds	747,893	5,206,682
Other non-current liabilities	1,061	7,389
Total non-current liabilities	748,954	5,214,071
Total liabilities	752,339	5,237,637		18,745
Shareholders' deficits
Additional paid-in capital	5,960,233	41,493,949		29,114,527
Accumulated other comprehensive income	208,025	1,448,230		1,035,783
Accumulated deficits	(2,627,979)	(18,295,461)		(11,327,858)
Total shareholders' equity	3,540,300	24,646,866		18,822,594
Total liabilities and shareholders' equity	$ 4,292,639	¥ 29,884,503		¥ 18,841,339
Parent Company | Reportable legal entity | Class A ordinary shares
Shareholders' equity
Ordinary shares, par value | $ / shares	$ 0.000005		0.000005
Ordinary shares, shares authorized	77,300,000,000	77,300,000,000		77,300,000,000
Ordinary shares, issued	2,575,580,988	2,575,580,988		2,381,240,988
Ordinary shares, outstanding	2,575,580,988	2,575,580,988		2,381,240,988
Shareholders' deficits
Common Shares	$ 12	¥ 84		¥ 78
Parent Company | Reportable legal entity | Class B ordinary shares
Shareholders' equity
Ordinary shares, par value | $ / shares	$ 0.000005		$ 0.000005
Ordinary shares, shares authorized	2,200,000,000	2,200,000,000		2,200,000,000
Ordinary shares, issued	2,074,447,700	2,074,447,700
Ordinary shares, outstanding	2,074,447,700	2,074,447,700
Shareholders' deficits
Common Shares	$ 9	¥ 64		¥ 64

Condensed Financial Informati_4

Condensed Financial Information of the Company - Statements of comprehensive income (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Costs of revenues
Total costs of revenues	$ (910,508)	¥ (6,338,778)	¥ (2,905,249)	¥ (722,830)
Sales and marketing expenses	(3,903,337)	(27,174,249)	(13,441,813)	(1,344,582)
General and administrative expenses	(186,261)	(1,296,712)	(6,456,612)	(133,207)
Total operating expenses	(4,645,540)	(32,341,319)	(21,014,482)	(1,616,970)
Operating loss	(1,226,437)	(8,538,211)	(10,799,741)	(595,724)
Interest income	221,469	1,541,825	584,940	80,783
Interest Expense	20,951	145,858
Foreign exchange gain	9,075	63,179	10,037	(11,547)
Other loss	11,891	82,786	(12,361)	1,373
Share of results of equity investees	4,119	28,676
Loss before income tax expenses	(1,000,834)	(6,967,603)	(10,217,125)	(525,115)
Net loss	(1,000,834)	(6,967,603)	(10,217,125)	(525,115)
Other comprehensive income net of tax of nil
Foreign currency translation difference, net of tax of nil	59,244	412,447	1,058,884	(47,681)
Comprehensive loss	(941,590)	(6,555,156)	(9,158,241)	(572,796)
Other comprehensive income/(loss), tax		0	0	0
Foreign currency translation difference, tax		0	0	0
Online marketplace services
Costs of revenues
Total costs of revenues	(910,508)	(6,338,778)	(2,905,249)	(719,778)
Parent Company | Reportable legal entity
Costs of revenues
Total costs of revenues	89,019	619,733	491,069
Sales and marketing expenses	(6,858)	(47,746)	(4,106)
General and administrative expenses	(466)	(3,245)	(4,101)	(165)
Total operating expenses	(7,324)	(50,991)	(8,207)	(165)
Operating loss	(96,343)	(670,724)	(499,276)	(165)
Interest income	45,702	318,166	207,597	8,264
Interest Expense	(20,703)	(144,132)
Foreign exchange gain			113
Other loss	(4)	(31)
Share of results of equity investees	(929,484)	(6,470,882)	(9,925,559)	(533,214)
Loss before income tax expenses	(1,000,832)	(6,967,603)	(10,217,125)	(525,115)
Net loss	(1,000,832)	(6,967,603)	(10,217,125)	(525,115)
Other comprehensive income net of tax of nil
Foreign currency translation difference, net of tax of nil	59,244	412,447	1,058,884	(47,681)
Comprehensive loss	(941,588)	(6,555,156)	(9,158,241)	(572,796)
Other comprehensive income/(loss), tax		0	0	0
Foreign currency translation difference, tax		0	0	¥ 0
Parent Company | Reportable legal entity | Online marketplace services
Costs of revenues
Costs of online marketplace services	$ (89,019)	¥ (619,733)	¥ (491,069)

Condensed Financial Informati_5

Condensed Financial Information of the Company - Statement of cash flows (Details) ¥ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)	Dec. 31, 2019CNY (¥)	Dec. 31, 2018CNY (¥)	Dec. 31, 2017CNY (¥)
Statement of cash flows
Net cash provided by operating activities	$ 2,128,900	¥ 14,820,976	¥ 7,767,927	¥ 9,686,328
Cash flows from investing activities:
Proceeds from sales of short-term investments	3,561,957	24,797,630	50,000	1,633,000
Cash given to purchase of short term investments	(7,534,202)	(52,451,615)	(7,516,370)	(1,393,000)
Net cash provided by/(used in) investing activities	(4,067,867)	(28,319,678)	(7,548,509)	71,651
Cash flows from financing activities:
Proceeds from the initial public offering			11,879,944
Costs incurred for the initial public offering costs			(356,313)
Proceeds from follow-on offering	1,177,080	8,194,597
Costs incurred for the issuance costs of follow-on offering	28,839	200,769
Proceeds from issuance of convertible bonds	15,688	109,220
Proceeds from issuance of convertible bonds	1,015,987	7,073,101
Proceeds from issuance of convertible preferred shares			5,824,568	1,446,906
Costs incurred for the issuance of convertible preferred shares			(3,842)	(15,369)
Repurchase of Class B Ordinary Shares				(32,677)
Net cash provided by financing activities	2,277,390	15,854,731	17,344,357	1,398,860
Exchange rate effect on cash, cash equivalents and restricted cash	64,659	450,142	546,910	(47,681)
Increase in cash, cash equivalents and restricted cash	403,082	2,806,171	18,110,685	11,109,158
Cash, cash equivalents and restricted cash at beginning of year	4,386,751	30,539,686	12,429,001	1,319,843
Cash, cash equivalents and restricted cash at end of year	4,789,833	33,345,857	30,539,686	12,429,001
Parent Company | Reportable legal entity
Statement of cash flows
Net cash provided by operating activities	37,262	259,409	110,724	2,753
Cash flows from investing activities:
Proceeds from sales of short-term investments	868,969	6,049,590
Cash given to purchase of short term investments	(861,562)	(5,998,024)	(6,146,370)
Cash given to subsidiaries, the VIE and subsidiaries of the VIE	(2,914,926)	(20,293,132)	(6,749,831)	(1,058,908)
Net cash provided by/(used in) investing activities	(2,907,519)	(20,241,566)	(12,896,201)	(1,058,908)
Cash flows from financing activities:
Proceeds from the initial public offering			(11,879,944)
Costs incurred for the initial public offering costs			(356,313)
Proceeds from follow-on offering	1,177,080	8,194,597
Costs incurred for the issuance costs of follow-on offering	(28,839)	(200,769)
Proceeds from issuance of convertible bonds	1,015,987	7,073,101
Proceeds from issuance of convertible bonds	(15,275)	(106,344)
Proceeds from issuance of convertible preferred shares			5,824,568	1,446,906
Costs incurred for the issuance of convertible preferred shares			(3,842)	(15,369)
Repurchase of Class B Ordinary Shares				(32,677)
Net cash provided by financing activities	2,148,953	14,960,585	17,344,357	1,398,860
Exchange rate effect on cash, cash equivalents and restricted cash	20,331	141,540	319,221	(47,820)
Increase in cash, cash equivalents and restricted cash	(700,973)	(4,880,032)	4,878,101	294,885
Cash, cash equivalents and restricted cash at beginning of year	796,022	5,541,746	663,645	368,760
Cash, cash equivalents and restricted cash at end of year	$ 95,049	¥ 661,714	¥ 5,541,746	¥ 663,645