ThredUp (TDUP) 10-Q 9 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 01, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	001-40249
Entity Registrant Name	ThredUp Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-4009181
Entity Address, Address Line One	969 Broadway
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Oakland
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94607
City Area Code	415
Local Phone Number	402-5202
Title of each class	Class A common stock, $0.0001 par value per share
Trading Symbol(s)	TDUP
Name of each exchange on which registered	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Central Index Key	0001484778
Current Fiscal Year End Date	--12-31
Common stock Class A
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		52,241,001
Common stock Class B
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		45,251,139

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 160,912	$ 64,485
Marketable securities	100,762	0
Accounts receivable, net	1,895	1,823
Inventory, net	4,106	3,519
Other current assets	7,773	5,332
Total current assets	275,448	75,159
Operating lease right-of-use assets	20,455	23,656
Property and equipment, net	49,451	41,131
Other assets	4,864	2,965
Total assets	350,218	142,911
Current liabilities
Accounts payable	8,407	9,386
Accrued and other current liabilities	46,427	32,541
Seller payable	18,306	13,724
Operating lease liabilities, current	2,757	3,643
Current portion of long-term debt	7,757	3,270
Total current liabilities	83,654	62,564
Operating lease liabilities, non-current	19,225	21,574
Long-term debt	29,478	31,190
Other non-current liabilities	2,187	2,719
Total liabilities	134,544	118,047
Commitments and contingencies (Note 10)
Convertible preferred stock: $0.0001 par value; 100,000,000 and 68,139,958 shares authorized as of September 30, 2021 and December 31, 2020, respectively; 0 and 65,970,938 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	0	247,041
Stockholders’ equity:
Class A and B common stock, $0.0001 par value; 1,120,000,000 and 110,000,000 shares authorized as of September 30, 2021 and December 31, 2020, respectively; 97,328,041 and 12,889,760 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	10	1
Additional paid-in capital	513,124	29,989
Accumulated other comprehensive loss	(28)	0
Accumulated deficit	(297,432)	(252,167)
Total stockholders’ equity (deficit)	215,674	(222,177)
Total liabilities, convertible preferred stock and stockholders’ equity	$ 350,218	$ 142,911

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Liabilities, Convertible Preferred Stock and Stockholders’ Equity
Convertible preferred stock (in dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized (in shares)	100,000,000	68,139,958
Convertible preferred stock, shares outstanding (in shares)	0	65,970,938
Convertible preferred stock, shares issued (in shares)	0	65,970,938
Stockholders’ equity:
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	1,120,000,000	110,000,000
Common stock, shares issued (in shares)	97,328,041	12,889,760
Common stock, shares outstanding (in shares)	97,328,041	12,889,760

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Total revenue	$ 63,274	$ 46,932	$ 178,913	$ 142,582
Cost of revenue:
Total cost of revenue	17,180	14,156	48,969	44,169
Gross profit	46,094	32,776	129,944	98,413
Operating expenses:
Operations, product and technology	32,081	25,856	91,455	73,480
Marketing	16,941	10,614	48,344	34,513
Sales, general and administrative	12,569	6,891	34,206	20,762
Total operating expenses	61,591	43,361	174,005	128,755
Operating loss	(15,497)	(10,585)	(44,061)	(30,342)
Interest expense	(619)	(368)	(1,751)	(865)
Other (expense) income, net	1,418	(51)	604	331
Loss before provision for income taxes	(14,698)	(11,004)	(45,208)	(30,876)
Provision for income taxes	17	0	57	0
Net loss	$ (14,715)	$ (11,004)	$ (45,265)	$ (30,876)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.15)	$ (0.93)	$ (0.65)	$ (2.77)
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.15)	$ (0.93)	$ (0.65)	$ (2.77)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic (in shares)	96,348,658	11,810,075	70,112,601	11,144,362
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted (in shares)	96,348,658	11,810,075	70,112,601	11,144,362
Consignment
Revenue:
Total revenue	$ 48,071	$ 33,657	$ 141,356	$ 103,885
Cost of revenue:
Total cost of revenue	10,080	7,984	31,599	25,097
Product
Revenue:
Total revenue	15,203	13,275	37,557	38,697
Cost of revenue:
Total cost of revenue	$ 7,100	$ 6,172	$ 17,370	$ 19,072

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders’ Equity - USD ($) $ in Thousands	Total	ASC 842 adoption (eff. January 1, 2020)	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit	Accumulated DeficitASC 842 adoption (eff. January 1, 2020)
Beginning balance (in shares) at Dec. 31, 2019	65,928,261
Beginning balance at Dec. 31, 2019	$ 246,905
Ending balance (in shares) at Mar. 31, 2020	65,928,261
Ending balance at Mar. 31, 2020	$ 246,905
Beginning balance (in shares) at Dec. 31, 2019			10,647,380
Beginning balance at Dec. 31, 2019	(183,241)	$ (565)	$ 1	$ 20,483		$ (203,725)	$ (565)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			118,685
Exercise of stock options	10		$ 0	10
Stock-based compensation	1,442			1,442
Net loss	(13,215)					(13,215)
Ending balance (in shares) at Mar. 31, 2020			10,766,065
Ending balance at Mar. 31, 2020	$ (195,569)		$ 1	21,935		(217,505)
Beginning balance (in shares) at Dec. 31, 2019	65,928,261
Beginning balance at Dec. 31, 2019	$ 246,905
Ending balance (in shares) at Sep. 30, 2020	65,970,938
Ending balance at Sep. 30, 2020	$ 247,041
Beginning balance (in shares) at Dec. 31, 2019			10,647,380
Beginning balance at Dec. 31, 2019	(183,241)	$ (565)	$ 1	20,483		(203,725)	$ (565)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(30,876)
Ending balance (in shares) at Sep. 30, 2020			12,688,696
Ending balance at Sep. 30, 2020	$ (207,815)		$ 1	27,350		(235,166)
Beginning balance (in shares) at Mar. 31, 2020	65,928,261
Beginning balance at Mar. 31, 2020	$ 246,905
Ending balance (in shares) at Jun. 30, 2020	65,928,261
Ending balance at Jun. 30, 2020	$ 246,905
Beginning balance (in shares) at Mar. 31, 2020			10,766,065
Beginning balance at Mar. 31, 2020	(195,569)		$ 1	21,935		(217,505)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			193,030
Exercise of stock options	232			232
Stock-based compensation	1,966			1,966
Net loss	(6,657)					(6,657)
Ending balance (in shares) at Jun. 30, 2020			10,959,095
Ending balance at Jun. 30, 2020	$ (200,028)		$ 1	24,133		(224,162)
Convertible Preferred Stock
Preferred Stock - Series C - Warrant Exercise (in shares)	42,677
Preferred Stock - Series C - Warrant Exercise	$ 136
Ending balance (in shares) at Sep. 30, 2020	65,970,938
Ending balance at Sep. 30, 2020	$ 247,041
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			1,729,601
Exercise of stock options	1,568			1,568
Stock-based compensation	1,649			1,649
Net loss	(11,004)					(11,004)
Ending balance (in shares) at Sep. 30, 2020			12,688,696
Ending balance at Sep. 30, 2020	$ (207,815)		$ 1	27,350		(235,166)
Beginning balance (in shares) at Dec. 31, 2020	65,970,938
Beginning balance at Dec. 31, 2020	$ 247,041
Convertible Preferred Stock
Preferred stock conversion to Class B common stock (in shares)	(65,970,938)
Preferred stock conversion to Class B common stock	$ (247,041)
Ending balance (in shares) at Mar. 31, 2021	0
Ending balance at Mar. 31, 2021	$ 0
Beginning balance (in shares) at Dec. 31, 2020	12,889,760		12,889,760
Beginning balance at Dec. 31, 2020	$ (222,177)		$ 1	29,989	$ 0	(252,167)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			1,458,159
Exercise of stock options	1,875			1,875
Stock-based compensation	3,498			3,498
Conversion of preferred stock warrants to Class B common stock warrants	1,827			1,827
Preferred stock conversion to Class B common stock (in shares)			65,970,938
Preferred stock conversion to Class B common stock	247,041		$ 7	247,034
Sale of Class A common stock upon initial public offering, net of issuance costs (in shares)			13,800,000
Sale of Class A common stock upon initial public offering, net of issuance costs	175,534		$ 1	175,533
Cashless exercise of common stock warrant (in shares)			24,837
Net loss	(16,171)					(16,171)
Ending balance (in shares) at Mar. 31, 2021			94,143,694
Ending balance at Mar. 31, 2021	$ 191,427		$ 9	459,756	0	(268,338)
Beginning balance (in shares) at Dec. 31, 2020	65,970,938
Beginning balance at Dec. 31, 2020	$ 247,041
Ending balance (in shares) at Sep. 30, 2021	0
Ending balance at Sep. 30, 2021	$ 0
Beginning balance (in shares) at Dec. 31, 2020	12,889,760		12,889,760
Beginning balance at Dec. 31, 2020	$ (222,177)		$ 1	29,989	0	(252,167)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cashless exercise of common stock warrant (in shares)			128,643
Net loss	$ (45,265)
Ending balance (in shares) at Sep. 30, 2021	97,328,041		97,328,041
Ending balance at Sep. 30, 2021	$ 215,674		$ 10	513,124	(28)	(297,432)
Beginning balance (in shares) at Mar. 31, 2021	0
Beginning balance at Mar. 31, 2021	$ 0
Ending balance (in shares) at Jun. 30, 2021	0
Ending balance at Jun. 30, 2021	$ 0
Beginning balance (in shares) at Mar. 31, 2021			94,143,694
Beginning balance at Mar. 31, 2021	191,427		$ 9	459,756	0	(268,338)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			525,670
Exercise of stock options	959			959
Stock-based compensation	2,896			2,896
Cashless exercise of common stock warrant (in shares)			103,806
Issuance of common stock to settle restricted stock units (in shares)			8,170
Withholding taxes for the net share settlement of restricted stock units (in shares)			(1,174)
Withholding taxes for the net share settlement of restricted stock units	(29)			(29)
Other comprehensive loss	(36)				(36)
Net loss	(14,379)					(14,379)
Ending balance (in shares) at Jun. 30, 2021			94,780,166
Ending balance at Jun. 30, 2021	$ 180,838		$ 9	463,582	(36)	(282,717)
Ending balance (in shares) at Sep. 30, 2021	0
Ending balance at Sep. 30, 2021	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)			534,025
Exercise of stock options	1,023			1,023
Stock-based compensation	2,995			2,995
Sale of Class A common stock upon initial public offering, net of issuance costs (in shares)			2,000,000
Sale of Class A common stock upon initial public offering, net of issuance costs	45,525		$ 1	45,524
Issuance of common stock to settle restricted stock units (in shares)			13,850
Other comprehensive loss	8				8
Net loss	$ (14,715)					(14,715)
Ending balance (in shares) at Sep. 30, 2021	97,328,041		97,328,041
Ending balance at Sep. 30, 2021	$ 215,674		$ 10	$ 513,124	$ (28)	$ (297,432)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net loss	$ (45,265)	$ (30,876)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	6,147	3,868
Stock-based compensation expense	9,389	5,057
Reduction in the carrying amount of right-of-use assets	3,201	2,882
Changes in fair value of convertible preferred stock warrants and others	1,768	166
Changes in operating assets and liabilities:
Accounts receivable, net	(72)	1,032
Inventory, net	(587)	31
Other current and non-current assets	(4,720)	(176)
Accounts payable	574	6,029
Accrued and other current liabilities	14,082	4,252
Seller payable	4,582	4,023
Operating lease liabilities	(3,235)	(2,851)
Other non-current liabilities	4	1,700
Net cash used in operating activities	(14,132)	(4,863)
Cash flows from investing activities
Purchases of marketable securities	(102,715)	0
Maturities of marketable securities	1,600	0
Purchase of property and equipment	(15,207)	(14,359)
Net cash used in investing activities	(116,322)	(14,359)
Cash flows from financing activities
Proceeds from debt issuance, net of issuance costs	4,625	13,427
Repayment of debt	(2,000)	(1,190)
Proceeds from issuance of Class A common stock upon initial public offering and the follow-on offering, net of underwriting discounts and commissions	226,905	0
Proceeds from exercise of common stock options and withholding taxes for the net share settlement of restricted stock units	3,753	1,810
Payment of costs for the initial public offering and the follow-on offering	(4,251)	(651)
Net cash provided by financing activities	229,032	13,396
Net increase (decrease) in cash, cash equivalents and restricted cash	98,578	(5,826)
Cash, cash equivalents and restricted cash
Beginning of period	67,539	87,853
End of period	$ 166,117	$ 82,027

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business ThredUp Inc. (“ThredUp” or “Company”) was formed as a corporation in the State of Delaware in January 2009. ThredUp is a large resale platform that enables consumers to buy and sell secondhand women’s and kid’s apparel, shoes and accessories. The Company conducts its marketing and administrative functions from Oakland, California and Scottsdale, Arizona and operates its fulfillment centers in Pennsylvania, Georgia and Arizona. Initial Public Offering The Company’s registration statement on Form S-1 related to its initial public offering (“IPO”) was declared effective on March 25, 2021 by the Securities and Exchange Commission (“SEC”), and the Company’s Class A common stock began trading on the Nasdaq Global Select Market on March 26, 2021. Upon the closing of the IPO, the Company sold 13,800,000 shares of Class A common stock to the public at a price of $14.00 per share. The aggregate net proceeds were $175.5 million after deducting offering costs, underwriting discounts and commissions of $17.7 million. Immediately prior to the completion of the IPO, the Company filed its Amended and Restated Certificate of Incorporation, which authorized a total of 1,000,000,000 shares of Class A common stock, 120,000,000 shares of Class B common stock and 100,000,000 shares of undesignated preferred stock. Immediately prior to the completion of the IPO, 65,970,938 shares of the convertible preferr ed stock then outstanding were converted into an equivalent number of shares of Class B common stock. The Company reclassified the convertible preferred stock to Class B common stock and additional paid-in capital upon the conversion in the three months ended March 31, 2021. 12,889,760 shares of the outstanding historical common stock were reclassified into an equivalent number of shares of Class B common stock. 164,973 shares of the convertible preferred stock warrants were converted to an equivalent number of shares of Class B common stock warrants. Follow-on Public Offering On August 2, 2021, the Company issued and sold 2,000,000 shares of Class A common stock at a price of $24.25 per share in a registered public offering. The aggregate net proceeds were $45.5 million, after deducting $3.3 million of underwriting discounts and commissions and offering costs. Refer to Note 8, Common Stock and Common Stock Warrants for more details. Acquisition of Remix Global AD (“Remix”) On July 24, 2021, the Company entered into Share Purchase Agreements with the shareholders of Remix, a fashion resale company headquartered in Sofia, Bulgaria, to purchase 100% of the outstanding equity interests of Remix and its subsidiary (the “Remix Acquisition”). Upon the closing of the Remix Acquisition on October 7, 2021, the Company paid approximately $19.2 million in cash (including the repayment of approximately $12.1 million in outstanding debt of Remix). Shortly after the closing, the company paid approximately $6.2 million of other Remix liabilities. Subject to customary purchase price adjustments, the Company will also pay approximately $3.5 million in the form of 130,597 shares of newly-issued Class A common stock to be issued 18 months following the closing of the Remix Acquisition. With this acquisition, the Company adds a complementary operational infrastructure and an experienced management team to enable its expansion into Europe.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation and Use of Estimates The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany account balances and transactions have been eliminated upon consolidation. The unaudited condensed consolidated financial statements were prepared in accordance with generally accepted accounting principles (“GAAP”) in the United States for interim financial information and with the instructions to Form 10‑Q and Article 10 of Regulation S-X. As permitted under those rules, certain footnotes or other financial information can be condensed or omitted. The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts that are reported in the consolidated financial statements and the related disclosures. Actual results could differ from those estimates. Significant items subject to such estimates and assumptions include, but are not limited to, the useful lives of property and equipment, allowance for sales returns, allowance for bad debts, breakage on loyalty points and rewards, valuation of inventory, warrants, stock-based compensation, valuation of right-of-use assets and income taxes. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all normal and recurring adjustments necessary to present fairly the financial position of the Company as of September 30, 2021, and the results of operations and cash flows for the interim periods presented. The Company has not included the Statements of Other Comprehensive Income (Loss) for the three and nine months ended September 30, 2021 as the components of other comprehensive income (loss) for these periods have been immaterial. The accompanying condensed consolidated financial statements and related financial information should b e read in conjunction with the Company’s audited consolidated financial statements and related notes for the year ended December 31, 2020 included in the final prospectus for the IPO dated March 25, 2021. Concentrations of Credit Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, marketable securities and accounts receivable. The Company deposits cash at major financial institutions, and at times, such cash may exceed federally insured limits. The credit risk is believed to be minimal due to the financial position of the depository institutions in which those deposits are held. The Company has never experienced any losses on deposits since inception. The Company’s investment policy restricts cash investments to highly liquid, short to intermediate-term, high grade fixed income securities, and as a result, the Company believes its cash equivalents and marketable securities represent minimal credit risk. Revenue Recognition Revenue from Loyalty Reward Redemption or Expiration Revenue recognized from loyalty reward redemption or expiration was $3.6 million and $2.3 million for the three months ended September 30, 2021 and 2020, respectively, and $10.3 million and $3.8 million for the nine months ended September 30, 2021 and 2020, respectively. Cash, Cash Equivalents and Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets to the amounts shown in the condensed consolidated statements of cash flows (in thousands): September 30, December 31, 2021 2020 Cash and cash equivalents $ 160,912 $ 64,485 Restricted cash, current and non-current 5,205 3,054 Total cash, cash equivalents and restricted cash $ 166,117 $ 67,539 Restricted cash, non-current of $4.4 million and $2.7 million is included in the other assets in the condensed consolidated balance sheets statements as of September 30, 2021 and December 31, 2020, respectively . Net Loss Per Share Attributable to Common Stockholders The Company follows the two-class method when computing net loss per common share when shares issued meet the definition of participating securities. The rights, including the liquidation and dividend rights and sharing of losses, of the Class A common stock and Class B common stock are identical, other than voting rights. As the liquidation and dividend rights and sharing of losses are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. For periods in which the Company reports net losses, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, because potentially dilutive common shares are not assumed to have been issued if their effect is anti-dilutive. Marketable Securities The Company invests its excess cash in investment grade, short to intermediate-term, fixed income securities and recognizes the transaction on the trade-date. The Company’s marketable securities are classified as available-for-sale in current assets because they represent investments of cash available for current operations. Marketable securities are reported at fair value with unrealized gains and losses reported, net of tax, as a separate component of accumulated other comprehensive gain (loss) until realized. The marketable securities are reviewed periodically to identify possible other-than-temporary impairments. Realized gains or losses and other-than-temporary impairments, if any, on available-for sale securities are reported in other income, net as incurred. Fair Value Measurements Fair value accounting is applied for all financial assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis (at least annually). As of September 30, 2021 and December 31, 2020, the carrying amount of accounts receivable, other current assets, other assets, accounts payable, seller payable and accrued and other current liabilities approximated their estimated fair value due to their relatively short maturities. Management believes the terms of its long-term debt reflect current market conditions for an instrument with similar terms and maturity, therefore the carrying value of the Company’s debt approximated its fair value. Assets and liabilities recorded at fair value on a recurring basis on the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2—Inputs (other than quoted prices in active markets included in Level 1) are either directly or indirectly observable for the asset or liability. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Accounting Pronouncements Recently Adopted In August 2018, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract. The Company adopted ASU 2018-15 as of January 1, 2021. The adoption of ASU 2018-15 did not have a material impact on the Company’s condensed consolidated financial statements. In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivative and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) . The Company adopted ASU 2020-06 on January 1, 2021. The adoption of this ASU did not have any impact on the Company’s condensed consolidated financial statements. New Accounting Pronouncements Recently Issued But Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Financial Instruments and Fair

Financial Instruments and Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Financial Instruments and Fair Value Measurements	Financial Instruments and Fair Value Measurements The following table provides the financial instruments measured at fair value (in thousands): Fair Value as of September 30, 2021 Level 1 Level 2 Level 3 Total Assets Money market fund $ 88,768 $ — $ — $ 88,768 U.S. treasury securities 26,212 — — 26,212 Commercial paper — 500 — 500 Corporate debt securities 57,641 — — 57,641 U.S. government agency bonds 16,910 — — 16,910 Total financial assets $ 189,531 $ 500 $ — $ 190,031 Classified as: Cash and cash equivalents $ 89,269 Marketable securities 100,762 $ 190,031 For the three and nine months ended September 30, 2021, unrealized gains and losses on available-for-sale debt securities were immaterial. For all of the marketable securities, the Company utilizes third-party pricing services to obtain fair value. Third-party pricing methodologies incorporate bond terms and conditions, current performance data, proprietary pricing models, real-time quotes from contributing dealers, trade prices and other market data. As of December 31, 2020, the Company held $43.5 million of money market funds and $0.8 million of convertible preferred stock warrant liability. The money market funds were included within cash equivalents and were valued using Level 1 inputs. The convertible preferred stock warrant liability was included in other non-current liabilities and was valued using Level 3 inputs. There were no transfers between levels during the periods presented. For the three and nine months ended September 30, 2021, the Company recognized no material realized gains or losses on marketable securities. As of September 30, 2021, out of the $100.8 million carrying amount of market securities, $21.1 million had a contractual maturity date of less than one year and $79.7 million had a contractual maturity date between one to two years.

Property and Equipment, Net

Property and Equipment, Net	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment, Net	Property and Equipment, Net Property and equipment, net consists of the following (in thousands): September 30, December 31, 2021 2020 Property and equipment $ 67,668 $ 55,221 Less: accumulated depreciation and amortization (18,217) (14,090) Property and equipment, net $ 49,451 $ 41,131

Other Balance Sheet Details

Other Balance Sheet Details	9 Months Ended
	Sep. 30, 2021
Other Liabilities [Abstract]
Other Balance Sheet Details	Other Balance Sheet Details Accrued and other current liabilities consist of the following (in thousands): September 30, December 31, 2021 2020 Gift card and site credit liabilities $ 11,597 $ 9,362 Accrued vendor liabilities 6,941 3,407 Allowance for returns 6,671 3,389 Deferred revenue 6,160 5,094 Accrued compensation 4,877 3,443 Accrued taxes 4,455 4,594 Accrued other 5,726 3,252 $ 46,427 $ 32,541

Lease Agreements

Lease Agreements	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Lease Agreements	Lease Agreements The Company’s operating lease expense was $1.6 million and $1.8 million for the three months ended September 30, 2021 and 2020, respectively, and $5.5 million and $4.9 million for the nine months ended September 30, 2021 and 2020, respectively. Maturities of operating lease liabilities were as follows as of September 30, 2021 (in thousands): Amount Remainder of 2021 $ 771 2022 4,519 2023 4,508 2024 4,156 2025 2,760 Thereafter 12,292 Total lease payments 29,006 Less: imputed interest 7,024 Total lease liabilities 21,982 Less: current lease liabilities 2,757 Total non-current lease liabilities $ 19,225 In September 2021, the Company entered into an agreement to lease a storage, warehousing, office and distribution center in Dallas County, Texas (the “DC07 Lease”). The DC07 Lease is expected to commence in the fourth quarter of 2021 with an original term of 123 months. The base rent is approximately $28.1 million in aggregate. The landlord will provide the Company with a tenant improvement allowance of up to $8.8 million. In connection with the DC07 Lease, the Company is required to maintain a letter of credit for the benefit of the landlord in the amount of $4.3 million, of which $2.2 million was delivered in September 2021 and is included in restricted cash, non-current in the other assets in the condensed consolidated balance sheets statements as of September 30, 2021.

Long-term Debt and Convertible

Long-term Debt and Convertible Preferred Stock Warrants	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Long-term Debt and Convertible Preferred Stock Warrants	Long-term Debt and Convertible Preferred Stock Warrants The Company entered into a loan and security agreement (“Term Loan”) with Western Alliance Bank (“Bank”) for an aggregate amount up to $40.0 million to refinance its Loan and Security Agreement with Silicon Valley Bank (“SVB”) in February 2019. The Term Loan was amended three times before December 31, 2020. In February 2021, the Company amended and restated the loan and security agreement with the Bank to reflect all waivers and amendments to date. Subsequently, the Company borrowed an additional $5.0 million for an aggregate principal amount of $40.0 million. In connection with the additional $5.0 million draw, the Company issued additional warrant shares for Series E-1 preferred stock in the amount of 15,979 or (i) two percent of the additional advance amount drawn under the Term A Loans, divided by (ii) the applicable exercise price at the time the warrant is exercised. On May 14, 2021, the Company entered into the First Amendment to the Amended and Restated Loan and Security Agreement (the “First Amendment”) with the Bank. The First Amendment amended the Amended and Restated Loan and Security Agreement dated February 3, 2021, with the most notable change being a decrease in interest rate. In accordance with the First Amendment, the interest rate on the Term Loan is equal to 4.00% plus the prime rate published in The Wall Street Journal. As of September 30, 2021, the nominal interest rate was 5.50% and the effective interest rate was 6.65%. The Company is in compliance with the covenants as of September 30, 2021. The maturities of the loan agreement as of September 30, 2021 are as follows (in thousands): Amount Remainder of 2021 $ 2,000 2022 8,000 2023 8,000 2024 20,000 Thereafter — Total future principal 38,000 Less: unamortized debt discount 765 Less: current portion of long-term debt 7,757 Non-current portion of long-term debt $ 29,478 Warrants Issued with Loan and Security Agreement The Company issued various preferred stock warrants under its loan and security agreements with SVB and the Bank. Immediately prior to the conversion upon IPO and as of December 31, 2020, the following preferred stock warrant liabilities were outstanding. Description Issuance Date Expiration Date Balance Sheet Classification Exercise Price Per Share Immediately Prior to the Completion of IPO December 31, 2020 Series D 1/22/2015 1/22/2025 Liability $ 2.2600 13,382 13,382 Series D 4/20/2015 1/22/2025 Liability $ 2.2600 13,382 13,382 Series E-1 2/7/2019 5/29/2030 Liability $ 6.2581 63,917 63,917 Series F 5/29/2020 5/29/2030 Liability $ 6.8839 10,376 10,376 Series E-1 8/14/2020 5/29/2030 Liability $ 6.2581 31,958 31,958 Series E-1 11/25/2020 5/29/2030 Liability $ 6.2581 15,979 15,979 Series E-1 2/8/2021 5/29/2030 Liability $ 6.2581 15,979 — 164,973 148,994 The convertible preferred stock warrant liability of $0.8 million was included in other non-current liabilities in the consolidated balance sheet as of December 31, 2020. Immediately prior to the completion of IPO in March 2021, all 164,973 shares of the convertible preferred stock warrant were remeasured to fair value and converted to equivalent number of Class B common stock warrants. The Company reclassified the convertible preferred stock warrant liability to additional paid-in capital upon the conversion. Refer to Note 8, Common Stock and Common Stock Warrants for more details on common stock warrants.

Common Stock and Common Stock W

Common Stock and Common Stock Warrants	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Common Stock and Common Stock Warrants	Common Stock and Common Stock Warrants Each share of Class A common stock is entitled to one vote per share. Each share of Class B common stock is entitled to ten votes per share and is convertible at any time into one share of Class A common stock. Immediately prior to the completion of the IPO, 65,970,938 shares of the convertible preferred stock converted to an equivalent number of shares of Class B common stock and 164,973 shares of the convertible preferred stock warrants were converted to an equivalent number of Class B common stock warrants. On August 2, 2021, the Company completed a follow‑on public offering of Class A common stock at a price of $24.25 per share. The Company issued and sold 2,000,000 shares of Class A common stock. The aggregate net proceeds were $45.5 million after deducting $3.3 million of underwriting discounts and commissions and offering costs. The selling stockholders sold 5,388,024 shares of Class A common stock (including 963,655 shares that were offered and sold pursuant to the full exercise of the underwriters’ option to purchase additional shares), which were converted from Class B common stock. The Company did not receive any of the proceeds from the sale of the Class A common stock by the selling stockholders. During the nine months ended September 30, 2021, the Company issued 128,643 shares of Class B common stock through cashless net exercises of the entire 164,973 shares underlying Class B common stock warrants. No Class B common stock warrants were outstanding as of September 30, 2021. The table below summarizes the Class A common stock and Class B common stock issued and outstanding as of September 30, 2021. As of September 30, 2021 Authorized Issued and Outstanding Common stock Class A 1,000,000,000 32,534,812 Common stock Class B 120,000,000 64,793,229 Total common stock 1,120,000,000 97,328,041

Stock-Based Compensation Plans

Stock-Based Compensation Plans	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans 2021 Stock Option and Incentive Plan In February 2021, in connection with the IPO, the Company’s board of directors adopted the 2021 Stock Option and Incentive Plan (“2021 Plan”) to replace the Second Amended and Restated 2010 Stock Plan (“2010 Plan”), which was subsequently approved by the Company’s stockholders in March 2021. The 2021 Plan became effective on March 24, 2021. As of September 30, 2021, no stock options were granted under the 2021 Plan. As of September 30, 2021, 380,679 restricted stock units were granted under the 2021 Plan. 2021 Employee Stock Purchase Plan In February 2021, the Company’s board of directors adopted the Employee Stock Purchase Plan (“ESPP”), which was subsequently approved by the stockholders in March 2021. The ESPP became effective on March 24, 2021. The first offering period began on March 25, 2021, and there was $0.4 million in stock-based compensation related to the ESPP for the nine months ended September 30, 2021. IPO Options Under the 2010 Plan In August 2020, the Company’s board of directors approved stock options for 3,588,535 common shares to be granted to certain officers and employees with an exercise price of $2.05 per share. 50% of the options granted vest over a four -year period commencing on the effective date of the IPO. The remaining 50% of the options granted vest over a four -year period commencing on the one -year anniversary of the IPO. As these stock options vest upon the satisfaction of both a time-based condition and a performance condition, the fair value of these stock options of $6.7 million, in aggregate, will be recognized as compensation expense over the requisite service period using the accelerated attribution method . In the three and nine months ended in September 30, 2021, $0.6 million and $2.8 million, respectively, was recognized as compensation expense from such stock options subject to these performance conditions. Stock-based Compensation Total stock-based compensation expense by department is as follows (in thousands): Three months ended Nine months ended 2021 2020 2021 2020 Operations, product and technology $ 1,024 $ 987 $ 3,358 $ 2,572 Marketing 341 278 1,067 734 Sales, general and administrative 1,630 384 4,964 1,751 Total stock-based compensation expense $ 2,995 $ 1,649 $ 9,389 $ 5,057 As of September 30, 2021, there was approximately $23.1 million of total unrecognized stock-based compensation expense related to unvested options granted to employees under the Company’s stock option plan that is expected to be recognized over a weighted average period of 1.17 years. As of September 30, 2021, there was approximately $0.1 million of total unrecognized compensation expense related to unvested awards under the ESPP that is expected to be recognized over a weighted average period of 0.17 years.

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies The Company is subject to litigation claims and assessments from time to time in the ordinary course of business. The Company’s management does not believe that any such matters, individually or in the aggregate, will have a material adverse effect on the Company’s business, financial condition, results of operations, or cash flows. Indemnifications

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe quarterly income tax provision reflects an estimate of the corresponding quarter’s state taxes in the United States. The provision for income tax expense for the three and nine months ended September 30, 2021 and 2020 was determined based upon estimates of the Company’s annual effective tax rate for the years ending December 31, 2021 and 2020, respectively. Since the Company is in a full valuation allowance position, due to losses incurred since inception, the provision for taxes consist solely of certain state income taxes. The Company has no uncertain tax positions or any unrecognized tax benefits.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Stockholders	Net Loss Per Share Attributable to Common Stockholders The following participating securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented, because including them would have been anti-dilutive: As of September 30, 2021 2020 Outstanding stock options 20,795,697 23,093,405 Restricted stock units 352,031 — Employee stock plan purchases 101,305 — Convertible preferred stock — 65,970,938 Outstanding convertible preferred stock warrants — 133,015 Total 21,249,033 89,197,358

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Event	Subsequent EventOn October 7, 2021, the Company closed the Remix Acquisition. Refer to Note 1, Organization and Description of Business for more details.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Basis of Presentation	The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany account balances and transactions have been eliminated upon consolidation. The unaudited condensed consolidated financial statements were prepared in accordance with generally accepted accounting principles (“GAAP”) in the United States for interim financial information and with the instructions to Form 10‑Q and Article 10 of Regulation S-X. As permitted under those rules, certain footnotes or other financial information can be condensed or omitted.
Use of Estimates	The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts that are reported in the consolidated financial statements and the related disclosures. Actual results could differ from those estimates. Significant items subject to such estimates and assumptions include, but are not limited to, the useful lives of property and equipment, allowance for sales returns, allowance for bad debts, breakage on loyalty points and rewards, valuation of inventory, warrants, stock-based compensation, valuation of right-of-use assets and income taxes.
Concentrations of Credit Risk	Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash, cash equivalents, marketable securities and accounts receivable. The Company deposits cash at major financial institutions, and at times, such cash may exceed federally insured limits. The credit risk is believed to be minimal due to the financial position of the depository institutions in which those deposits are held. The Company has never experienced any losses on deposits since inception. The Company’s investment policy restricts cash investments to highly liquid, short to intermediate-term, high grade fixed income securities, and as a result, the Company believes its cash equivalents and marketable securities represent minimal credit risk.
Net Loss Per Share Attributable to Common Stockholders	The Company follows the two-class method when computing net loss per common share when shares issued meet the definition of participating securities. The rights, including the liquidation and dividend rights and sharing of losses, of the Class A common stock and Class B common stock are identical, other than voting rights. As the liquidation and dividend rights and sharing of losses are identical, the undistributed earnings are allocated on a proportionate basis and the resulting net loss per share attributed to common stockholders will, therefore, be the same for both Class A and Class B common stock on an individual or combined basis. For periods in which the Company reports net losses, diluted net loss per share attributable to common stockholders is the same as basic net loss per share attributable to common stockholders, because potentially dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.
Marketable Securities	The Company invests its excess cash in investment grade, short to intermediate-term, fixed income securities and recognizes the transaction on the trade-date. The Company’s marketable securities are classified as available-for-sale in current assets because they represent investments of cash available for current operations. Marketable securities are reported at fair value with unrealized gains and losses reported, net of tax, as a separate component of accumulated other comprehensive gain (loss) until realized. The marketable securities are reviewed periodically to identify possible other-than-temporary impairments. Realized gains or losses and other-than-temporary impairments, if any, on available-for sale securities are reported in other income, net as incurred.
Accounting Pronouncements Recently Adopted and New Accounting Pronouncements Recently Issue But Not Yet Adopted	In August 2018, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2018-15, Intangibles—Goodwill and Other—Internal-use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract. The Company adopted ASU 2018-15 as of January 1, 2021. The adoption of ASU 2018-15 did not have a material impact on the Company’s condensed consolidated financial statements. In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivative and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) . The Company adopted ASU 2020-06 on January 1, 2021. The adoption of this ASU did not have any impact on the Company’s condensed consolidated financial statements. New Accounting Pronouncements Recently Issued But Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets to the amounts shown in the condensed consolidated statements of cash flows (in thousands): September 30, December 31, 2021 2020 Cash and cash equivalents $ 160,912 $ 64,485 Restricted cash, current and non-current 5,205 3,054 Total cash, cash equivalents and restricted cash $ 166,117 $ 67,539
Restrictions on Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the condensed consolidated balance sheets to the amounts shown in the condensed consolidated statements of cash flows (in thousands): September 30, December 31, 2021 2020 Cash and cash equivalents $ 160,912 $ 64,485 Restricted cash, current and non-current 5,205 3,054 Total cash, cash equivalents and restricted cash $ 166,117 $ 67,539

Financial Instruments and Fai_2

Financial Instruments and Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Financial Instruments Measured at Fair Value	The following table provides the financial instruments measured at fair value (in thousands): Fair Value as of September 30, 2021 Level 1 Level 2 Level 3 Total Assets Money market fund $ 88,768 $ — $ — $ 88,768 U.S. treasury securities 26,212 — — 26,212 Commercial paper — 500 — 500 Corporate debt securities 57,641 — — 57,641 U.S. government agency bonds 16,910 — — 16,910 Total financial assets $ 189,531 $ 500 $ — $ 190,031 Classified as: Cash and cash equivalents $ 89,269 Marketable securities 100,762 $ 190,031

Property and Equipment, Net (Ta

Property and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net consists of the following (in thousands): September 30, December 31, 2021 2020 Property and equipment $ 67,668 $ 55,221 Less: accumulated depreciation and amortization (18,217) (14,090) Property and equipment, net $ 49,451 $ 41,131

Other Balance Sheet Details (Ta

Other Balance Sheet Details (Tables)	9 Months Ended
	Sep. 30, 2021
Other Liabilities [Abstract]
Schedule of Other Current Liabilities	Accrued and other current liabilities consist of the following (in thousands): September 30, December 31, 2021 2020 Gift card and site credit liabilities $ 11,597 $ 9,362 Accrued vendor liabilities 6,941 3,407 Allowance for returns 6,671 3,389 Deferred revenue 6,160 5,094 Accrued compensation 4,877 3,443 Accrued taxes 4,455 4,594 Accrued other 5,726 3,252 $ 46,427 $ 32,541

Lease Agreements (Tables)

Lease Agreements (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities were as follows as of September 30, 2021 (in thousands): Amount Remainder of 2021 $ 771 2022 4,519 2023 4,508 2024 4,156 2025 2,760 Thereafter 12,292 Total lease payments 29,006 Less: imputed interest 7,024 Total lease liabilities 21,982 Less: current lease liabilities 2,757 Total non-current lease liabilities $ 19,225

Long-term Debt and Convertibl_2

Long-term Debt and Convertible Preferred Stock Warrants (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Maturities of Debt	The maturities of the loan agreement as of September 30, 2021 are as follows (in thousands): Amount Remainder of 2021 $ 2,000 2022 8,000 2023 8,000 2024 20,000 Thereafter — Total future principal 38,000 Less: unamortized debt discount 765 Less: current portion of long-term debt 7,757 Non-current portion of long-term debt $ 29,478
Schedule of Warrants Issued	Description Issuance Date Expiration Date Balance Sheet Classification Exercise Price Per Share Immediately Prior to the Completion of IPO December 31, 2020 Series D 1/22/2015 1/22/2025 Liability $ 2.2600 13,382 13,382 Series D 4/20/2015 1/22/2025 Liability $ 2.2600 13,382 13,382 Series E-1 2/7/2019 5/29/2030 Liability $ 6.2581 63,917 63,917 Series F 5/29/2020 5/29/2030 Liability $ 6.8839 10,376 10,376 Series E-1 8/14/2020 5/29/2030 Liability $ 6.2581 31,958 31,958 Series E-1 11/25/2020 5/29/2030 Liability $ 6.2581 15,979 15,979 Series E-1 2/8/2021 5/29/2030 Liability $ 6.2581 15,979 — 164,973 148,994

Common Stock and Common Stock_2

Common Stock and Common Stock Warrants (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Schedule of Common Stock Issued and Outstanding	The table below summarizes the Class A common stock and Class B common stock issued and outstanding as of September 30, 2021. As of September 30, 2021 Authorized Issued and Outstanding Common stock Class A 1,000,000,000 32,534,812 Common stock Class B 120,000,000 64,793,229 Total common stock 1,120,000,000 97,328,041

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Stock-based Compensation Expense	Total stock-based compensation expense by department is as follows (in thousands): Three months ended Nine months ended 2021 2020 2021 2020 Operations, product and technology $ 1,024 $ 987 $ 3,358 $ 2,572 Marketing 341 278 1,067 734 Sales, general and administrative 1,630 384 4,964 1,751 Total stock-based compensation expense $ 2,995 $ 1,649 $ 9,389 $ 5,057

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Participating Securities Excluded From the Computation of Diluted Net Loss Per Share	The following participating securities were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented, because including them would have been anti-dilutive: As of September 30, 2021 2020 Outstanding stock options 20,795,697 23,093,405 Restricted stock units 352,031 — Employee stock plan purchases 101,305 — Convertible preferred stock — 65,970,938 Outstanding convertible preferred stock warrants — 133,015 Total 21,249,033 89,197,358

Organization and Description _2

Organization and Description of Business (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 07, 2021	Aug. 02, 2021	Mar. 26, 2021	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020	Jul. 24, 2021	Mar. 25, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Price per share of common stock (in dollars per share)		$ 24.25
Aggregate net proceeds		$ 45,500
Payment of costs for the initial public offering			$ 17,700
Common stock, shares authorized (in shares)					1,120,000,000				110,000,000
Shares authorized (in shares)			100,000,000		100,000,000				68,139,958
Warrants outstanding (in shares)								164,973	148,994
Payments of stock issuance costs		$ 3,300			$ 4,251	$ 651
Remix Global AD
Class of Stock [Line Items]
Percentage of ownership acquired							100.00%
Subsequent Event | Remix Global AD
Class of Stock [Line Items]
Cash consideration	$ 19,200
Repayment of outstanding debt	12,100
Other liabilities paid	6,200
Payment of shares issued	$ 3,500
Shares issued (in shares)	130,597
Period of shares issued	18 months
Class B Common Stock Warrant
Class of Stock [Line Items]
Warrants outstanding (in shares)			164,973		0			164,973
Common Stock
Class of Stock [Line Items]
Stock converted (in shares)			65,970,938	65,970,938
Conversion of stock (in shares)			12,889,760
Common stock Class A
Class of Stock [Line Items]
Shares sold (in shares)		2,000,000
Common stock, shares authorized (in shares)			1,000,000,000		1,000,000,000
Common stock Class B
Class of Stock [Line Items]
Common stock, shares authorized (in shares)			120,000,000		120,000,000
Stock converted (in shares)					164,973
IPO
Class of Stock [Line Items]
Shares sold (in shares)			13,800,000
Price per share of common stock (in dollars per share)			$ 14
Aggregate net proceeds			$ 175,500

Significant Accounting Polici_4

Significant Accounting Policies - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue from External Customer [Line Items]
Restricted cash, non-current	$ 4.4		$ 4.4		$ 2.7
Loyalty Program
Revenue from External Customer [Line Items]
Revenue recognized	$ 3.6	$ 2.3	$ 10.3	$ 3.8

Significant Accounting Polici_5

Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Accounting Policies [Abstract]
Cash and cash equivalents	$ 160,912	$ 64,485
Restricted cash, current and non-current	5,205	3,054
Total cash, cash equivalents and restricted cash	$ 166,117	$ 67,539	$ 82,027	$ 87,853

Financial Instruments and Fai_3

Financial Instruments and Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Marketable securities	$ 100,762	$ 0
Classified as:
Cash and cash equivalents	160,912	64,485
Convertible preferred stock warrant liability		800
Marketable securities, between one to two years	21,100
Marketable securities, less than one year	79,700
Fair Value, Recurring
Assets
Marketable securities	100,762
Total financial assets	190,031
Classified as:
Cash and cash equivalents	89,269
Convertible preferred stock warrant liability		800
Fair Value, Recurring | U.S. treasury securities
Assets
Marketable securities	26,212
Fair Value, Recurring | Corporate debt securities
Assets
Marketable securities	57,641
Fair Value, Recurring | U.S. government agency bonds
Assets
Marketable securities	16,910
Fair Value, Recurring | Money market fund
Assets
Cash and cash equivalents	88,768	$ 43,500
Fair Value, Recurring | Commercial paper
Assets
Cash and cash equivalents	500
Fair Value, Recurring | Level 1
Assets
Total financial assets	189,531
Fair Value, Recurring | Level 1 | U.S. treasury securities
Assets
Marketable securities	26,212
Fair Value, Recurring | Level 1 | Corporate debt securities
Assets
Marketable securities	57,641
Fair Value, Recurring | Level 1 | U.S. government agency bonds
Assets
Marketable securities	16,910
Fair Value, Recurring | Level 1 | Money market fund
Assets
Cash and cash equivalents	88,768
Fair Value, Recurring | Level 1 | Commercial paper
Assets
Cash and cash equivalents	0
Fair Value, Recurring | Level 2
Assets
Total financial assets	500
Fair Value, Recurring | Level 2 | U.S. treasury securities
Assets
Marketable securities	0
Fair Value, Recurring | Level 2 | Corporate debt securities
Assets
Marketable securities	0
Fair Value, Recurring | Level 2 | U.S. government agency bonds
Assets
Marketable securities	0
Fair Value, Recurring | Level 2 | Money market fund
Assets
Cash and cash equivalents	0
Fair Value, Recurring | Level 2 | Commercial paper
Assets
Cash and cash equivalents	500
Fair Value, Recurring | Level 3
Assets
Total financial assets	0
Fair Value, Recurring | Level 3 | U.S. treasury securities
Assets
Marketable securities	0
Fair Value, Recurring | Level 3 | Corporate debt securities
Assets
Marketable securities	0
Fair Value, Recurring | Level 3 | U.S. government agency bonds
Assets
Marketable securities	0
Fair Value, Recurring | Level 3 | Money market fund
Assets
Cash and cash equivalents	0
Fair Value, Recurring | Level 3 | Commercial paper
Assets
Cash and cash equivalents	$ 0

Property and Equipment, Net - S

Property and Equipment, Net - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and equipment	$ 67,668	$ 55,221
Less: accumulated depreciation and amortization	(18,217)	(14,090)
Property and equipment, net	$ 49,451	$ 41,131

Property and Equipment, Net - N

Property and Equipment, Net - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation	$ 2.2	$ 1.4	$ 6.1	$ 3.9

Other Balance Sheet Details (De

Other Balance Sheet Details (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other Liabilities [Abstract]
Gift card and site credit liabilities	$ 11,597	$ 9,362
Accrued vendor liabilities	6,941	3,407
Allowance for returns	6,671	3,389
Deferred revenue	6,160	5,094
Accrued compensation	4,877	3,443
Accrued taxes	4,455	4,594
Accrued other	5,726	3,252
Total	$ 46,427	$ 32,541

Lease Agreements - Narrative (D

Lease Agreements - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Lessee, Lease, Description [Line Items]
Operating lease expense		$ 1.6	$ 1.8	$ 5.5	$ 4.9
Lease not yet commenced, term of contract	123 months	123 months		123 months
Lease not yet commenced, base rent	$ 28.1
Tenant improvement allowance	8.8
Letters of credit	4.3	$ 4.3		$ 4.3
Other Noncurrent Assets
Lessee, Lease, Description [Line Items]
Letters of credit	$ 2.2	$ 2.2		$ 2.2

Lease Agreements - Maturities o

Lease Agreements - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Remainder of 2021	$ 771
2022	4,519
2023	4,508
2024	4,156
2025	2,760
Thereafter	12,292
Total lease payments	29,006
Less: imputed interest	7,024
Total lease liabilities	21,982
Less: current lease liabilities	2,757	$ 3,643
Total non-current lease liabilities	$ 19,225	$ 21,574

Long-term Debt and Convertibl_3

Long-term Debt and Convertible Preferred Stock Warrants - Narrative (Details) - USD ($)	May 14, 2021	Feb. 28, 2021	Sep. 30, 2021	Mar. 26, 2021	Mar. 25, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Outstanding principal			$ 38,000,000
Convertible preferred stock warrant liability						$ 800,000
Warrants outstanding (in shares)					164,973	148,994
Class B Common Stock Warrant
Debt Instrument [Line Items]
Warrants outstanding (in shares)			0	164,973	164,973
Term Loan | Series E-1 Convertible Preferred Stock
Debt Instrument [Line Items]
Warrants converted (in shares)		15,979
Percent of additional advance amount drawn		2.00%
Medium-term Notes | Term Loan
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 40,000,000
Borrowed amount		5,000,000
Outstanding principal		$ 40,000,000
Stated interest rate			5.50%
Effective interest rate			6.65%
Medium-term Notes | Term Loan | Prime Rate | Minimum
Debt Instrument [Line Items]
Variable interest rate	4.00%

Long-term Debt and Convertibl_4

Long-term Debt and Convertible Preferred Stock Warrants - Schedule of Maturities of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Remainder of 2021	$ 2,000
2022	8,000
2023	8,000
2024	20,000
Thereafter	0
Total future principal	38,000
Less: unamortized debt discount	765
Less: current portion of long-term debt	7,757	$ 3,270
Non-current portion of long-term debt	$ 29,478	$ 31,190

Long-term Debt and Convertibl_5

Long-term Debt and Convertible Preferred Stock Warrants - Schedule of Warrants Issued (Details) - $ / shares	Mar. 25, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Warrants outstanding (in shares)	164,973	148,994
Series D Convertible Preferred Stock, Issued 1/22/2015
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 2.2600
Warrants outstanding (in shares)	13,382	13,382
Series D Convertible Preferred Stock, Issued 4/20/2015
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 2.2600
Warrants outstanding (in shares)	13,382	13,382
Series E1 Convertible Preferred Stock, Issued 2/7/2019
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 6.2581
Warrants outstanding (in shares)	63,917	63,917
Series F Convertible Preferred Stock, Issued 5/29/2020
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 6.8839
Warrants outstanding (in shares)	10,376	10,376
Series E1 Convertible Preferred Stock, Issued 8/14/2020
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 6.2581
Warrants outstanding (in shares)	31,958	31,958
Series E1 Convertible Preferred Stock, Issued 11/25/2020
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 6.2581
Warrants outstanding (in shares)	15,979	15,979
Series E1 Convertible Preferred Stock, Issued 2/28/2021
Debt Instrument [Line Items]
Exercise Price Per Share (in dollars per share)	$ 6.2581
Warrants outstanding (in shares)	15,979	0

Common Stock and Common Stock_3

Common Stock and Common Stock Warrants - Narrative (Details) $ / shares in Units, $ in Thousands	Aug. 02, 2021USD ($)$ / sharesshares	Mar. 26, 2021voteshares	Jun. 30, 2021shares	Mar. 31, 2021shares	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)	Mar. 25, 2021shares	Dec. 31, 2020shares
Class of Stock [Line Items]
Warrants outstanding (in shares)							164,973	148,994
Price per share of common stock (in dollars per share) | $ / shares	$ 24.25
Aggregate net proceeds | $	$ 45,500
Payments of stock issuance costs | $	$ 3,300				$ 4,251	$ 651
Common Stock
Class of Stock [Line Items]
Stock converted (in shares)		65,970,938		65,970,938
Cashless exercise of common stock warrant (in shares)			103,806	24,837	128,643
Class B Common Stock Warrant
Class of Stock [Line Items]
Warrants outstanding (in shares)		164,973			0		164,973
Common stock Class A
Class of Stock [Line Items]
Number of votes for each share | vote		1
Shares sold (in shares)	2,000,000
Common stock Class A | Follow-On Public Offering | Selling Stockholders
Class of Stock [Line Items]
Shares sold (in shares)	5,388,024
Common stock Class A | Over-Allotment Option | Selling Stockholders
Class of Stock [Line Items]
Shares sold (in shares)	963,655
Common stock Class B
Class of Stock [Line Items]
Number of votes for each share | vote		10
Conversion of stock (in shares)		1
Stock converted (in shares)					164,973

Common Stock and Common Stock_4

Common Stock and Common Stock Warrants - Schedule of Common Stock Issued and Outstanding (Details) - shares	Sep. 30, 2021	Mar. 26, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Authorized (in shares)	1,120,000,000		110,000,000
Issued (in shares)	97,328,041		12,889,760
Outstanding (in shares)	97,328,041		12,889,760
Common stock Class A
Class of Stock [Line Items]
Authorized (in shares)	1,000,000,000	1,000,000,000
Issued (in shares)	32,534,812
Outstanding (in shares)	32,534,812
Common stock Class B
Class of Stock [Line Items]
Authorized (in shares)	120,000,000	120,000,000
Issued (in shares)	64,793,229
Outstanding (in shares)	64,793,229

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 2,995	$ 1,649	$ 9,389	$ 5,057
Unrecognized stock-based compensation expense		23,100		$ 23,100
2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)				0
2010 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares)	3,588,535
Options granted (in dollars per share)	$ 2.05
Fair value of stock options	$ 6,700
Restricted stock units | 2021 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs granted (in shares)				380,679
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense				$ 400
Weighted average period for unrecognized stock-based compensation expense				2 months 1 day
Unrecognized compensation expense		100		$ 100
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period for unrecognized stock-based compensation expense				1 year 2 months 1 day
Options | 2010 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense		$ 600		$ 2,800
Option Vesting Four Years From Commencement | 2010 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%
Vesting percentage period	4 years
Option Vesting Four Years From IPO | 2010 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%
Vesting percentage period	4 years
Anniversary period	1 year

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 2,995	$ 1,649	$ 9,389	$ 5,057
Operations, product and technology
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,024	987	3,358	2,572
Marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	341	278	1,067	734
Sales, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,630	$ 384	$ 4,964	$ 1,751

Income Taxes (Details)

Income Taxes (Details)	Sep. 30, 2021USD ($)
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 0

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders (Details) - shares	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	21,249,033	89,197,358
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	20,795,697	23,093,405
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	352,031	0
Employee stock plan purchases
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	101,305	0
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	0	65,970,938
Outstanding convertible preferred stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total (in shares)	0	133,015

Uncategorized Items - tdup-2021

Label	Element	Value
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-02 [Member]