ACV Auctions (ACVA) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 03, 2021
Document Information [Line Items]
Entity Registrant Name	ACV Auctions Inc.
Entity Central Index Key	0001637873
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Document Type	10-Q
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Trading Symbol	ACVA
Amendment Flag	false
Title of 12(b) Security	Class A common stock, par value $0.001 per share
Security Exchange Name	NASDAQ
Entity File Number	001-40256
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-2415221
Entity Address, Address Line One	640 Ellicott Street, #321
Entity Address, City or Town	Buffalo
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	14203
City Area Code	800
Local Phone Number	553-4070
Document Quarterly Report	true
Document Transition Report	false
Common Class A [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		93,285,078
Common Class B [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		62,290,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Total revenue	$ 91,798	$ 67,460	$ 258,258	$ 154,594
Operating expenses:
Operations and technology	26,395	16,792	71,489	47,613
Selling, general, and administrative	33,787	11,639	85,275	48,601
Depreciation and amortization	2,348	1,665	5,877	4,337
Total operating expenses	116,448	63,925	309,371	183,244
Income (loss) from operations	(24,650)	3,535	(51,113)	(28,650)
Other income (expense):
Interest Income	29	69	100	719
Interest expense	(121)	(159)	(582)	(450)
Total other income (expense)	(92)	(90)	(482)	269
Income (loss) before income taxes	(24,742)	3,445	(51,595)	(28,381)
Provision for income taxes	61	286	275	381
Net income (loss)	$ (24,803)	$ 3,159	$ (51,870)	$ (28,762)
Weighted-average shares
Basic	155,037,911	21,742,708	115,075,030	21,437,785
Diluted	155,037,911	139,240,687	115,075,030	21,437,785
Net earnings (loss) per share
Basic	$ (0.16)	$ 0.15	$ (0.45)	$ (1.34)
Diluted	$ (0.16)	$ 0.02	$ (0.45)	$ (1.34)
Marketplace And Service Cost [Member]
Operating expenses:
Cost of revenue	$ 41,547	$ 25,064	$ 113,844	$ 61,994
Customer Assurance Cost [Member]
Operating expenses:
Cost of revenue	12,371	8,765	32,886	20,699
Marketplace And Service Revenue [Member]
Total revenue	79,306	56,367	221,632	129,273
Customer Assurance Revenue [Member]
Total revenue	$ 12,492	$ 11,093	$ 36,626	$ 25,321

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ (24,803)	$ 3,159	$ (51,870)	$ (28,762)
Other comprehensive income (loss):
Foreign currency translation (loss) gain	(51)	1	25	(6)
Comprehensive income (loss)	$ (24,854)	$ 3,160	$ (51,845)	$ (28,768)

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current Assets :
Cash and cash equivalents	$ 601,651	$ 233,725
Trade receivables (net of allowance of $3,034 and $2,093)	215,645	104,138
Finance receivables (net of allowance of $266 and $40)	35,074	8,501
Other current assets	12,375	8,041
Total current assets	864,745	354,405
Property and equipment (net of accumulated depreciation of $4,053 and $2,439)	5,162	4,912
Goodwill	69,938	21,820
Acquired intangible assets (net of amortization of $5,874 and $3,059)	21,476	11,491
Internal-use software costs (net of amortization of $3,270 and $1,963)	14,868	7,775
Operating lease right-of-use assets	1,458	2,000
Other assets	2,613	2,147
Total assets	980,260	404,550
Current Liabilities :
Accounts payable	376,305	151,967
Accrued payroll	12,985	8,109
Accrued other liabilities	6,180	4,375
Deferred revenue	4,380	1,504
Operating lease liabilities	807	746
Total current liabilities	400,657	166,701
Long-term operating lease liabilities	710	1,323
Long-term debt	500	4,832
Other long-term liabilities	2,342	5,054
Total liabilities	404,209	177,910
Commitments and Contingencies (Note 3)
Convertible Preferred Stock :
Convertible preferred stock; $0.001 par value; 0 and 230,538,501 shares authorized; 0 and 115,269,221 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	0	366,332
Stockholders' Equity (Deficit) :
Preferred Stock; $0.001 par value; 20,000,000 and 0 shares authorized; 0 and 0 shares issued and outstanding at September 30, 2021 and December 31, 2020, respectively	0	0
Common stock	0	22
Additional paid-in capital	794,777	27,322
Accumulated deficit	(218,849)	(166,979)
Accumulated other comprehensive loss	(32)	(57)
Total stockholders' equity (deficit)	576,051	(139,692)
Total liabilities, convertible preferred stock and stockholders' equity (deficit)	980,260	404,550
Common Class A [Member]
Stockholders' Equity (Deficit) :
Common stock	90	0
Common Class B [Member]
Stockholders' Equity (Deficit) :
Common stock	$ 65	$ 0

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts Receivable, Allowance	$ 3,034	$ 2,093
Financing Receivable, Allowance	266	40
Accumulated depreciation pf property and equipment	4,053	2,439
Amortization of intangible assets	5,874	3,059
Software Development [Member]
Amortization of intangible assets	$ 3,270	$ 1,963
Convertible Preferred Stock [Member]
Temporary equity, par value	$ 0.001	$ 0.001
Temporary equity, shares authorized	0	230,538,501
Temporary equity, shares issued	0	115,269,221
Temporary equity, shares outstanding	0	115,269,221
Common Class A [Member]
Common stock, shares authorized	2,000,000,000
Common Class B [Member]
Common stock, shares authorized	160,000,000
Preferred Stock [Member]
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	20,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common Stock [Member]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	0	311,100,000
Common stock, shares issued	0	22,331,842
Common stock, shares outstanding	0	22,331,842
Common Stock [Member] | Common Class A [Member]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	0
Common stock, shares issued	90,158,968	0
Common stock, shares outstanding	90,158,968	0
Common Stock [Member] | Common Class B [Member]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	160,000,000	0
Common stock, shares issued	65,187,200	0
Common stock, shares outstanding	65,187,200	0

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS' EQUITY (DEFICIT) (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock [Member]	Common Stock [Member]	Common Class A [Member]	Common Class B [Member]	Additional Paid In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	I P O [Member]	I P O [Member]Common Class A [Member]	I P O [Member]Additional Paid In Capital [Member]
Balance at Dec. 31, 2019		$ 311,468
Balance, Shares at Dec. 31, 2019		110,627,173
Balance at Dec. 31, 2019	$ (106,142)		$ 21			$ 19,796	$ (125,958)	$ (1)
Balance, Shares at Dec. 31, 2019			21,078,342
Issuance of Series E-1 Preferred Stock net of issuance costs of $136		$ 54,885
Issuance of Series E-1 Preferred Stock net of issuance costs of $136, Shares		4,642,048
Issuance of common stock from the exercise of stock options	1,003		$ 1			1,002
Issuance of common stock from the exercise of stock options, Shares			866,057
Stock-based compensation	3,473					3,473
Other comprehensive income (loss)	(6)							(6)
Net income (loss)	(28,762)						(28,762)
Balance at Sep. 30, 2020		$ 366,353
Balance, Shares at Sep. 30, 2020		115,269,221
Balance at Sep. 30, 2020	(130,434)		$ 22			24,271	(154,720)	(7)
Balance, Shares at Sep. 30, 2020			21,944,399
Balance at Jun. 30, 2020		$ 311,468
Balance, Shares at Jun. 30, 2020		110,627,173
Balance at Jun. 30, 2020	(134,755)		$ 21			23,111	(157,879)	(8)
Balance, Shares at Jun. 30, 2020			21,438,899
Issuance of Series E-1 Preferred Stock net of issuance costs of $136		$ 54,885
Issuance of Series E-1 Preferred Stock net of issuance costs of $136, Shares		4,642,048
Issuance of common stock from the exercise of stock options	818		$ 1			817
Issuance of common stock from the exercise of stock options, Shares			505,500
Stock-based compensation	343					343
Other comprehensive income (loss)	1							1
Net income (loss)	3,159						3,159
Balance at Sep. 30, 2020		$ 366,353
Balance, Shares at Sep. 30, 2020		115,269,221
Balance at Sep. 30, 2020	(130,434)		$ 22			24,271	(154,720)	(7)
Balance, Shares at Sep. 30, 2020			21,944,399
Balance at Dec. 31, 2020		$ 366,332
Balance, Shares at Dec. 31, 2020		115,269,221
Balance at Dec. 31, 2020	(139,692)		$ 22			27,322	(166,979)	(57)
Balance, Shares at Dec. 31, 2020			22,331,842
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs									$ 385,068	$ 17	$ 385,051
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs, Shares										16,550,000
Issuance of common stock from the exercise of stock options	$ 1,095		$ 0	$ 1	$ 0	1,094
Issuance of common stock from the exercise of stock options, Shares	1,073,448		375,971	694,736	2,715
Stock-based compensation	$ 16,422					16,422
Issuance of common stock for vested restricted stock units	(1,329)			$ 0		(1,329)
Issuance of common stock for vested restricted stock units, Shares				121,657
Conversion of redeemable convertible preferred stock to common stock		$ (366,332)
Conversion of redeemable convertible preferred stock to common stock, Shares		(115,269,221)
Conversion of redeemable convertible preferred stock to common stock	366,332				$ 115	366,217
Conversion of redeemable convertible preferred stock to common stock, Shares					115,269,221
Sale of Common Stock to Underwriters				$ 2	$ (2)
Sale of Common Stock to Underwriters, Shares				2,482,500	(2,482,500)
Reclassification of common stock, Amount			$ (22)		$ 22
Reclassification of Common Stock, Shares			22,707,813		(22,707,813)
Conversion of Class B Common Stocks to Class A Common Stocks, Value				$ 70	$ (70)
Conversion of Class B Common Stocks to Class A Common Stocks, Shares				70,310,049	(70,310,049)
Other comprehensive income (loss)	25							25
Net income (loss)	(51,870)						(51,870)
Balance at Sep. 30, 2021		$ 0
Balance, Shares at Sep. 30, 2021		0
Balance at Sep. 30, 2021	576,051		$ 0	$ 90	$ 65	794,777	(218,849)	(32)
Balance, Shares at Sep. 30, 2021			0	90,158,942	65,187,200
Balance at Jun. 30, 2021	592,002			$ 40	$ 114	785,875	(194,046)	19
Balance, Shares at Jun. 30, 2021				40,225,160	114,445,042
Other offering costs in connection with initial public offering									$ 24		$ 24
Issuance of common stock from the exercise of stock options	421			$ 1	$ 0	420
Issuance of common stock from the exercise of stock options, Shares				554,283
Stock-based compensation	9,787					9,787
Issuance of common stock for vested restricted stock units	(1,329)			$ 0		(1,329)
Issuance of common stock for vested restricted stock units, Shares				121,657
Conversion of Class B Common Stocks to Class A Common Stocks, Value				$ 49	$ (49)
Conversion of Class B Common Stocks to Class A Common Stocks, Shares				49,257,842	(49,257,842)
Other comprehensive income (loss)	(51)							(51)
Net income (loss)	(24,803)						(24,803)
Balance at Sep. 30, 2021		$ 0
Balance, Shares at Sep. 30, 2021		0
Balance at Sep. 30, 2021	$ 576,051		$ 0	$ 90	$ 65	$ 794,777	$ (218,849)	$ (32)
Balance, Shares at Sep. 30, 2021			0	90,158,942	65,187,200

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS EQUIT (DEFICIT)(Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020
Statement Of Stockholders Equity [Abstract]
Costs Of Issuance Preferred Stock	$ 136	$ 136

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash Flows from Operating Activities
Net income (loss)	$ (51,870)	$ (28,762)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	6,221	5,204
Stock-based compensation expense	16,417	3,473
Provision for bad debt	2,518	4,455
Non-cash operating lease costs	(9)	7
(Gain) on contingent liabilities	0	(2,600)
Other non-cash, net	505	174
Changes in operating assets and liabilities, net of effects from purchases of businesses:
Trade receivables	(111,953)	(44,172)
Other current assets	(3,887)	(4,926)
Accounts payable	223,510	82,464
Accrued payroll	4,260	2,875
Accrued other liabilities	1,518	148
Deferred revenue	1,690	(502)
Other long-term liabilities	(75)	2,980
Other assets	(428)	(502)
Net cash provided by (used in) operating activities	88,417	20,316
Cash Flows from Investing Activities
Net increase in finance receivables	(26,972)	(3,128)
Purchases of property and equipment	(2,197)	(2,989)
Capitalization of software costs	(8,546)	(3,681)
Acquisition of business (net of cash acquired)	(59,931)	(5,500)
Net cash provided by (used in) investing activities	(97,646)	(15,298)
Cash Flows from Financing Activities
Proceeds from issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs	385,738	0
Proceeds from long term debt	5,250	5,187
Proceeds from issuance of Series E1 preferred stock	0	54,886
Payments towards long-term debt	(9,582)	(1,980)
Payments towards promissory note	(2,637)	0
Payments for debt issuance and other financing costs	(1,385)	0
Payment of RSU tax withholdings in exchange for common shares surrendered by RSU holders	(1,329)	0
Proceeds from exercise of common stock options	1,100	1,003
Net cash provided by (used in) financing activities	377,155	59,096
Net increase (decrease) in cash and cash equivalents	367,926	64,114
Cash and cash equivalents, beginning of period	233,725	182,275
Cash and cash equivalents, end of period	601,651	246,389
Cash paid (received) during the period for:
Interest (income) expense	522	98
Income taxes	210	(6)
Cash paid included in the measurement of operating lease liabilities	0	553
Non-cash investing and financing activities:
Contingent consideration	0	5,700
Right-of-use assets obtained, including initial adoption	0	718
Purchase of property and equipment in accounts payable	$ 410	$ 0

Nature of Business and Summary

Nature of Business and Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Nature of Business and Summary Significant Accounting Policies	Note 1. Nature of Business and Summary of Significant Accounting Policies Nature of Business —ACV Auctions Inc. (“the Company" or "ACV”) was formed on December 31, 2014. The Company operates in one industry segment, providing a digital wholesale auction marketplace (the “Marketplace”) to facilitate business-to-business used vehicle sales between a selling dealership (“Seller”) and a buying dealership (“Buyer”). Customers using the Marketplace are licensed automotive dealerships or other commercial automotive enterprises. At the election of the customer purchasing a vehicle, the Company can arrange third-party transportation services for the delivery of the purchased vehicle through its wholly owned subsidiary, ACV Transportation LLC. The Company can also provide the customer financing for the purchased vehicle through its wholly owned subsidiary, ACV Capital LLC. ACV also provides data services that offer insights into the condition and value of used vehicles for transactions both on and off our Marketplace, which help dealerships, their end customers, and commercial partners make more informed decisions to transact with confidence and efficiency. Customers using data services are licensed automotive dealerships or other commercial automotive enterprises. All services are provided in the United States and are supported by the Company’s operations which are in both the United States and Canada. Basis of Consolidation — The consolidated financial statements include the accounts of ACV Auctions Inc. and all of its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Basis of Preparation — The accompanying unaudited interim consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and pursuant to the applicable rules and regulations of the Securities and Exchange Commission ("SEC"). The Company has condensed or omitted certain information and notes normally included in complete annual financial statements prepared in accordance with GAAP. These financial statements have been prepared on the same basis as the Company's annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for the fair statement of the Company's financial information. The unaudited interim consolidated financial statements should therefore be read in conjunction with the audited consolidated financial statements and accompanying notes included in Form 424B4 ("Prospectus"), filed with the SEC on March 24, 2021. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”). Initial Public Offering — On March 26, 2021, the Company completed its initial public offering (“IPO”), in which the Company issued and sold 16,550,000 shares of its Class A common stock at a public offering price of $ 25.00 per share, which resulted in net proceeds of $ 388.9 million after deducting underwriting discounts and commissions. On March 26, 2021, the underwriters exercised their option to purchase an additional 2,482,500 shares of Class A common stock at $ 25.00 per share from selling stockholders identified in the Prospectus. The Company did no t receive any of the proceeds from the sale of any shares of Class A common stock by the selling stockholders upon such exercise. Immediately prior to the closing of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock and all shares of the convertible preferred stock then outstanding automatically converted into 115,269,221 shares of Class B common stock. Prior to the IPO, deferred offering costs, which consist of direct incremental legal, accounting, and consulting fees relating to the IPO, were capitalized in prepaid expenses and other current assets in the condensed consolidated balance sheets. Upon the consummation of the IPO, $ 3.9 million of net deferred offering costs were reclassified into stockholders’ equity as an offset against IPO proceeds. Emerging Growth Company —The Company is an “emerging growth company,” as defined in Section 2(a) of the Securities Act of 1933, as amended (the "Securities Act"), as modified by the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”), and it may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in its periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and shareholder approval of any golden parachute payments not previously approved. Further, Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Securities Exchange Act of 1934, as amended (“Exchange Act”)) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such election to opt out is irrevocable. The Company has elected not to opt out of such extended transition period which means that when a standard is issued or revised and it has different application dates for public or private companies, the Company, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of the Company’s financial statements with another public company which is neither an emerging growth company nor an emerging growth company which has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used. Stock-Based Compensation— The Company uses the fair value recognition provisions of ASC 718, Compensation – Stock Compensation . The estimated fair value of each Common Stock option award is calculated on the date of grant using the Black-Scholes option pricing model. Application of the Black-Scholes option pricing model requires significant judgment, and involves the use of subjective assumptions including: Expected Term —The expected term represents the period that the stock-based awards are expected to be outstanding. As the Company does not have sufficient historical experience for determining the expected term of the stock option awards granted, the simplified method was used to determine the expected term for awards issued to employees. Risk-Free Interest Rate —The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the date of grant for zero-coupon U.S. Treasury constant maturity notes with terms approximately equal to the stock-based awards’ expected term. Expected Volatility —Since the Company is newly public and does not have a trading history of common stock, the expected volatility is derived from the average historical volatilities of the common stock of several public companies considered to be comparable to the Company over a period equivalent to the expected term of the stock-based awards. Dividend Rate —The expected dividend rate is zero as the Company has not paid and does not anticipate paying any dividends in the foreseeable future. Fair Value of Common Stock —Prior to the IPO, the Company estimated the fair value of common stock. The Board of Directors, with input from management, considered numerous objective and subjective factors to determine the fair value of the Company’s common stock at each meeting in which awards were approved. Subsequent to the IPO, the fair value of the underlying common stock is determined by the closing price, on the date of grant, of the Company’s Class A common stock, which is traded publicly on the Nasdaq Global Select Market. The Company measures all stock options and other stock-based awards granted to employees, directors, consultants and other nonemployees based on the fair value on the date of the grant. The options vest based on a graded scale over the stated vesting period, and compensation expense is recognized based on their grant date fair value on a straight-line basis over the vesting period. Forfeitures are recognized as they occur. The fair value of restricted stock awards and units are determined based on the estimated market price of the Company’s Common Stock on the grant date. The awards and units vest over time and compensation expense is recognized based on their grant date fair value ratably over the vesting period. The Company classifies stock-based compensation expense in its Condensed Consolidated Statements of Operations in the same way the payroll costs or service payments are classified for the related stock-based award recipient. Marketplace and Service Revenue— As described in Note 12, the Company acquired Max Digital LLC ("Max Digital") on July 12, 2021. Through Max Digital, the Company generates data services revenue from software related services. Subscription revenue is recognized on a ratable basis over the contractual subscription term of the arrangement, as the underlying service is a stand-ready performance obligation, beginning on the date that our services are made available to the customer. Implementation and training revenue is recognized over time as services are transferred to our customers. Accounting Pronouncements— The following table provides a description of accounting standards that were adopted by the Company as well as standards that are not yet adopted that could have an impact to the consolidated financial statements upon adoption. Accounting Standard Update Description Required Effect on consolidated Accounting Standards Adopted Simplifying the Accounting for Income Taxes (ASU 2019-12) The guidance simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC 740. January 1, 2022 Early adoption permitted The guidance was early adopted on January 1, 2021 on a prospective basis and did not have a material impact to the consolidated financial statements. Accounting Standards Not Yet Adopted Measurement of Credit Losses on Financial Instruments (ASU 2016-13, 2018-19, 2019-04, 2019-05, 2019-10, 2019-11, 2020-02, 2020-03) The guidance changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. January 1, 2023 Early adoption permitted The Company is currently evaluating the impact this guidance may have on the consolidated financial statements. The Company reviewed all other recently issued accounting standards and concluded that they were not applicable to the consolidated financial statements.

Accounts Receivables & Allowanc

Accounts Receivables & Allowance for Doubtful Receivables	9 Months Ended
	Sep. 30, 2021
Accounts Receivable Net [Abstract]
Accounts Receivables & Allowance for Doubtful Receivables	2. Accounts Receivables & Allowance for Doubtful Receivables The Company maintains an allowance for doubtful receivables that in management’s judgement reflects losses inherent in the portfolio. Changes in the allowance for doubtful trade receivables for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Beginning balance 3,158 $ 2,282 $ 2,092 $ 1,352 Provision for bad debt 676 781 2,119 4,380 Net write-offs Write-offs ( 1,193 ) ( 2,013 ) ( 3,951 ) ( 5,423 ) Recoveries 393 1,132 2,774 1,873 Net write-offs ( 800 ) ( 881 ) ( 1,177 ) ( 3,550 ) Ending balance $ 3,034 $ 2,182 $ 3,034 $ 2,182 Changes in the allowance for doubtful finance receivables for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Beginning balance $ 96 $ 40 $ 40 $ 65 Provision for bad debt 253 4 399 75 Net write-offs Write-offs ( 96 ) ( 4 ) ( 186 ) ( 100 ) Recoveries 14 - 14 - Net write-offs ( 83 ) ( 4 ) ( 173 ) ( 100 ) Ending balance $ 266 $ 40 $ 266 $ 40

Guarantees, Commitments and Con

Guarantees, Commitments and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments And Contingencies Disclosure [Abstract]
Guarantees, Commitments and Contingencies	3. Guarantees, Commitments and Contingencies The Company provides certain guarantees to Sellers in the Marketplace in the ordinary course of business, which are accounted for under ASC 460 as a general guarantee. Vehicle Condition Guarantees —Sellers must attach a vehicle condition report in the Marketplace for every auction; this vehicle condition report is used by Buyers to inform bid decisions. The Company offers guarantees to Sellers in qualifying situations where the Company performed a vehicle inspection and prepared the vehicle condition report. Sellers must pay an additional fee in exchange for this guarantee. The guarantee provides Sellers protection from paying remedies to Buyers related to a Buyer’s claim that the vehicle condition report did not accurately portray the condition of the vehicle purchased on the Marketplace. The guarantee provides the Company with the right to retain proceeds from the subsequent liquidation of the vehicle covered under the guarantee. The guarantee is typically provided for 10 days after the successful sale of the vehicle on the Marketplace. The fair value of vehicle condition guarantees issued is estimated based on historical results and other qualitative factors. The vehicle condition guarantee revenue is recognized on the earlier of the guarantee expiration date or the guarantee settlement date. The maximum potential payment is the sale price of the vehicle. The total sale price of vehicles for which there was an outstanding guarantee was $ 284.0 million and $ 95.7 million at September 30, 2021 and December 31, 2020, respectively. The carrying amount of the liability presented in Accrued other liabilities was $ 1.5 million and $ 1.0 million at September 30, 2021 and December 31, 2020, respectively. The recognized probable loss contingency, in excess of vehicle condition guarantees recognized, presented in Accrued other liabilities was $ 1.0 million and $ 1.1 million at September 30, 2021 and December 31, 2020, respectively. Other Price Guarantees —The Company provides Sellers with a price guarantee for vehicles to be sold on the Marketplace from time to time. If a vehicle sells below the guaranteed price, the Company is responsible for paying the Seller the difference between the guaranteed price and the final sale price. The term of the guarantee is typically less than one week. No material unsettled price guarantees existed at September 30, 2021 and December 31, 2020. Litigation —The Company and its subsidiaries are subject in the normal course of business to various pending and threatened legal proceedings and matters in which claims for monetary damages are asserted. On an on-going basis management, after consultation with legal counsel, assesses the Company's liabilities and contingencies in connection with such proceedings. For those matters for where it is probable that the Company will incur losses and the amounts of the losses can be reasonably estimated, the Company records an expense and corresponding liability in its consolidated financial statements. To the extent pending or threatened litigation could result in exposure in excess of the recorded liability, the amount of such excess is not currently estimable. On March 19, 2021, a putative class action was filed against ACV Auctions Inc., et al. in the U.S. District Court for the Western District of New York, alleging violations of the federal antitrust laws and New York State law related to an alleged conspiracy to set bids on our marketplace from transactions that originated from one seller. The complaint seeks statutory damages under such laws and other relief. In July 2021, the complaint was amended to add and modify allegations beyond the initial complaint, as well as to add certain individuals as individual defendants, including George Chamoun, the Company's Chief Executive Officer. The Company intends to vigorously defend itself in this case. Due to the inherent uncertainties of litigation, the Company cannot accurately predict the ultimate outcome and cannot estimate the range of any potential loss at this time. However, the Company believes that the resolution of this matter will not have a material adverse effect on its consolidated financial position.

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Borrowings	4. Borrowings The Company’s outstanding long-term debt consisted of the following at September 30, 2021 and December 31, 2020 (in thousands): September 30, December 31, Interest Rate * Maturity Date * 2021 2020 2019 Revolver LIBOR + 3.75% June 25, 2024 $ 500 $ 4,832 Total long-term debt $ 500 $ 4,832 * The interest rate and maturity date presented in the table above represent the rate and maturity date in place as of September 30, 2021 As of September 30, 2021 and December 31, 2020, the Company had outstanding $ 0.5 million and $ 4.8 million , respectively, of indebtedness, consisting entirely of outstanding borrowings under the 2019 Revolver. 2019 Revolver On December 20, 2019, the Company entered into a revolving credit facility (the "2019 Revolver"). The 2019 Revolver was established to provide debt financing in support of the short-term finance receivable product offered to eligible customers purchasing vehicles through the Marketplace and is fully secured by the underlying finance receivable assets. On June 25, 2021 the Company entered into the First Amendment to Loan and Security Agreement ("The First Amendment"), which modified the interest rate to LIBOR (or a benchmark replacement in accordance with The First Amendment) + 3.75 % and extended the maturity date to June 25, 2024 . The First Amendment maintains a maximum borrowing principal amount of $ 50.0 million . The amount available for borrowing under the 2019 Revolver is based on the size of the finance receivable portfolio. As of September 30, 2021, $ 49.5 million of the revolving line of credit was unused . The revolving feature on the facility ends on June 25, 2023 . Amounts owed at that time will amortize and be due on or before June 25, 2024, depending on the collection of the outstanding finance receivables securing the facility. The facility carried an interest rate of 4.75 % as of September 30, 2021. 2021 Revolver On August 24, 2021, the Company entered into a revolving credit facility (the "2021 Revolver"). The 2021 Revolver was established to provide general working capital to the Company. The 2021 Revolver is secured by substantially all of the Company's assets. The maximum borrowing principal amount of the 2021 Revolver is $ 160.0 million and includes a sub facility that provides for the issuance of letters of credit up to $ 20.0 million outstanding at any time. The 2021 Revolver matures on August 24, 2026 and is subject to a commitment fee of 0.25 % per annum of the average daily undrawn portion of the revolving credit facility. The applicable interest rate is, at the Company's option, either (a) LIBOR (or a replacement rate established in accordance with the terms of the credit agreement) (subject to a 0.00% LIBOR floor), plus a margin of 2.75% per annum or (b) the Alternative Base Rate plus a margin of 1.75% per annum . The Alternative Base Rate is the highest of (a) the Wall Street Journal prime rate, (b) the NYFRB rate plus 0.5%, and (c)(i) 1.00% plus (ii) the adjusted LIBOR rate for a one-month interest period. As of September 30, 2021, there was an outstanding letter of credit issued under the 2021 Revolver in the amount of $ 0.5 million , decreasing availability under the 2021 Revolver by a corresponding amount. There were no other amounts outstanding under the 2021 Revolver. The Company's ability to borrow under both the 2019 Revolver and 2021 Revolver is subject to ongoing compliance with a combination of financial and non-financial covenants. The 2019 Revolver is also subject to ongoing compliance with non-financial collateral performance metrics. As of September 30, 2021 , the Company was in compliance with all of its covenants and collateral performance metrics.

Convertible Preferred Stock and

Convertible Preferred Stock and Stockholders' Deficit	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Convertible Preferred Stock and Stockholders' Deficit	5. Convertible Preferred Stock and Stockholders' Deficit Convertible Preferred Stock Upon closing of the IPO on March 26, 2021, all of the then-outstanding shares of convertible preferred stock automatically converted into 115,269,221 shares of Class B common stock on a one-for-one basis . There were no shares of convertible preferred stock outstanding subsequent to the closing of the IPO. Common Stock On March 11, 2021, the Board of Directors and the stockholders of the Company approved an amended and restated certificate of incorporation that implemented a dual class common stock structure where all existing shares of common stock converted to Class B common stock and a new class of common stock, Class A common stock, became authorized. The amended and restated certificate of incorporation became effective immediately prior to the closing of the IPO on March 26, 2021. The authorized share capital of Class A common stock of the Company is 2,000,000,000 and the authorized share capital for Class B common stock is 160,000,000 . The Class A common stock is entitled to one vote per share and the Class B common stock is entitled to ten votes per share. The Class A and Class B common stock have the same rights and privileges and rank equally, share ratably, and are identical in all respects for all matters except for the voting, conversion, and transfer rights. The Class B common stock converts to Class A common stock at any time at the option of the holder. During the three and nine months ended September 30, 2021, 49,257,842 and 70,310,049 Class B shares converted to an equal number of shares of Class A common stock, respectively.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2021
Revenue From Contract With Customer [Abstract]
Revenue	6. Revenue The following table summarizes the primary components of revenue, this level of disaggregation takes into consideration how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors (in thousands): Three months ended September 30, For the nine months ended September 30, 2021 2020 2021 2020 Auction marketplace revenue $ 40,006 $ 32,776 $ 120,863 $ 74,139 Transportation, data, and other services 39,300 23,591 100,769 55,134 Marketplace and service revenue $ 79,306 $ 56,367 $ 221,632 $ 129,273 Revenue presented in the table above, including the subsequent cash flows, could be negatively impacted by fluctuations in the supply or demand of used vehicles, especially in the case of an economic downturn in the United States.

Stock-Based Employee Compensati

Stock-Based Employee Compensation	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Employee Compensation	7. Stock-Based Employee Compensation Effective March 20, 2015, the Company adopted the ACV Auctions Inc. 2015 Long-Term Incentive Plan (the "2015 Plan"). Employees, outside directors, consultants and advisors of the Company were eligible to participate in the 2015 Plan. The Plan allowed for the grant of incentive or nonqualified common stock options to purchase shares of the Company’s common stock and also to issue restricted shares of the common stock. Effective March 23, 2021, the Company adopted the ACV Auctions Inc. 2021 Equity Incentive Plan (the "2021 Plan"). The 2021 Plan became effective on the date of the underwriting agreement related to the IPO, and no further grants were made under the 2015 Plan. Employees, outside directors, consultants and advisors of the Company are eligible to participate in the 2021 Plan. The Plan allows the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units, performance awards, and other forms of awards. As of September 30, 2021, 12,719,849 shares were available for future grants of the Company's common stock. The following table summarizes the stock option activity for the nine months ended September 30, 2021 (in thousands, except for share and per share amounts): Number of Weighted- Intrinsic Weighted- Outstanding, December 31, 2020 9,933,348 $ 2.16 $ 129,358 7.80 Granted 633,700 8.10 Exercised ( 1,073,448 ) 1.02 Forfeited ( 169,975 ) 4.46 Expired ( 38,111 ) 2.08 Outstanding, September 30, 2021 9,285,514 $ 2.66 $ 141,393 7.23 Exercisable, September 30, 2021 5,574,039 $ 1.24 $ 92,813 6.32 Expected to Vest, September 30, 2021 3,711,475 $ 4.79 $ 48,579 8.60 The following table summarizes the restricted stock unit activity for the nine months ended September 30, 2021 (in thousands, except for share and per share amounts): Number of RSUs Weighted- Outstanding, December 31, 2020 250,000 $ 10.52 Granted 3,178,671 22.10 Vested ( 178,513 ) 17.83 Forfeited ( 10,260 ) 22.46 Outstanding, September 30, 2021 3,239,898 $ 21.44 As of September 30, 2021, there is approximately $ 84.0 million of compensation expense related to the unvested portion of common stock options and restricted stock units. The weighted-average remaining period of the compensation expense related to common stock options and restricted stock units are 2.39 and 3.49 years, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	8. Income Taxes The Company had an effective tax rate of approximately 0 % and 8 % for the three months ended September 30, 2021 and 2020, respectively, and ( 1 )% for each of the nine months ended September 30, 2021 and 2020 . The principal difference between the federal statutory rate and the effective tax rate is related to the non-recognition of tax benefits for certain entities in a loss position for which a full valuation allowance has been recorded.

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement	. Fair Value Measurement Fair value accounting is applied for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the consolidated financial statements on a recurring basis. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. Assets and liabilities recorded at fair value in the consolidated financial statements are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels, which are directly related to the amount of subjectivity, associated with the inputs to the valuation of these assets or liabilities are as follows: Level 1: Observable inputs such as quoted prices in active markets for identical assets and liabilities. Level 2: Inputs other than the quoted prices in active markets that are observable either directly or indirectly. Level 3: Unobservable inputs in which there is little or no market data which require the Company to develop its own assumptions. The Company’s financial instruments primarily consist of cash and cash equivalents, trade and finance accounts receivable and accounts payable whose carrying values approximate fair value due to the short-term nature of those instruments. The Company had no assets requiring fair value hierarchy disclosures as of September 30, 2021 or December 31, 2020. The Company records guarantees accounted for under ASC 460 at fair value when issued. The fair value of the guarantees were no t material as of September 30, 2021 and December 31, 2020 .

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Earnings (Loss) Per Share	10. Net Income (Loss) Per Share The numerators and denominators of the basic and diluted net income (loss) per share computations for the Company's common stock are calculated as follows for the three and nine months ended September 30, 2021 and 2020 (in thousands, except share data): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Class A Class B Class A Class B Numerator: Net income (loss) attributable to common $ ( 9,202 ) $ ( 15,601 ) $ 3,159 $ ( 13,064 ) $ ( 38,806 ) $ ( 28,762 ) Denominator: Weighted-average number of shares of common 57,516,336 97,521,575 21,742,708 28,982,025 86,093,005 21,437,785 Dilutive effect of convertible preferred stock - - 112,056,011 - - - Dilutive effect of assumed conversion of options - - 5,299,908 - - - Dilutive effect of assumed conversion of - - 142,060 - - - Weighted-average number of shares of common 57,516,336 97,521,575 139,240,687 28,982,025 - 86,093,005 21,437,785 Net income (loss) per share attributable to $ ( 0.16 ) $ ( 0.16 ) $ 0.15 $ ( 0.45 ) $ ( 0.45 ) $ ( 1.34 ) Net income (loss) per share attributable to $ ( 0.16 ) $ ( 0.16 ) $ 0.02 $ ( 0.45 ) $ ( 0.45 ) $ ( 1.34 ) The following table presents the total weighted-average number of potentially dilutive shares that were excluded from the computation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the period presented: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Convertible Preferred Stock Series Seed I, Seed II, - - - 111,106,946 Unvested RSAs and RSUs 281,082 - 381,656 321,609 Stock options not subject to performance 7,440,345 - 7,950,194 5,653,104

Reverse Stock Split

Reverse Stock Split	9 Months Ended
	Sep. 30, 2021
Stockholders Equity Note [Abstract]
Reverse Stock Split	11. Reverse Stock Split On March 11, 2021, the Board of Directors and the stockholders of the Company approved a 1-for-2 reverse stock split of the Company’s outstanding common stock and convertible preferred stock. All common stock, convertible preferred stock, and per share information have been retroactively adjusted to give effect to this reverse stock split for all periods presented. Shares of common stock underlying outstanding stock options, restricted stock units, and restricted stock awards were proportionately decreased and the retrospective per share value and exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such securities. There were no changes in the par values of the Company’s common stock and convertible preferred stock as a result of the reverse stock split.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Acquisitions	12. Acquisitions Max Digital LLC On July 12, 2021 , the Company completed its acquisition of all of the outstanding shares of Max Digital , for approximately $ 61.4 million . The total purchase price was paid in cash. Max Digital is a pioneer in automotive data and merchandising products, and is best known for its flagship inventory management system platform. Max Digital's software products enable dealers to accurately price wholesale and retail inventory while maximizing profit on each vehicle sold by leveraging predictive analytics informed by machine learning. The acquisition of Max Digital enabled the Company to expand its position in the used vehicle industry and enhance its service offerings with dealers and commercial partners. The transaction was accounted for using the acquisition method and, accordingly, the results of the acquired business have been included in the Company's results of operations from the acquisition date. In connection with the acquisition, the Company incurred approximately $ 1.0 million of transaction costs recorded in the Selling, general and administrative line of the Consolidated Statement of Operations. The fair value of consideration transferred in this business combination was preliminarily allocated to the tangible and intangible assets acquired and liabilities assumed at the acquisition date, with the remaining unallocated amount recorded as goodwill. The goodwill acquired in connection with this acquisition will be deductible for tax purposes and will be amortized on a straight-line basis over 15 years . The purchase price allocation is subject to adjustments as valuation is finalized during the measurement period. The aggregate purchase price was preliminarily allocated to the assets acquired and liabilities assumed as follows (in thousands): Assets Acquired Cash and cash equivalents 1,458 Trade receivables 1,673 Other current assets 448 Property & equipment, net 30 Goodwill and intangible assets 60,918 Total assets acquired $ 64,527 Liabilities Assumed Accounts payable 1,084 Accrued payroll 616 Accrued other liabilities 252 Deferred Revenue 1,186 Total liabilities assumed 3,138 Net assets acquired $ 61,389 As the Company has determined that the acquisition is not material to its existing operations, certain disclosures, including pro forma financial information, have not been included. TruePartners USA LLC The Company had a contingent liability related to an earn-out provision based on TruePartners USA LLC achieving certain revenue targets for fiscal year 2020 and 2021. This contingent liability was accounted for as compensation expense and was not included in the calculation of purchase consideration. An agreement was reached to amend the earn-out provision during the three months ended September 30, 2021, and as a result, the Company recorded $ 3.4 million of compensation expense during that period. The amendment resolved the contingent liability in full.

Nature of Business and Summa_2

Nature of Business and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Nature of Business	Nature of Business —ACV Auctions Inc. (“the Company" or "ACV”) was formed on December 31, 2014. The Company operates in one industry segment, providing a digital wholesale auction marketplace (the “Marketplace”) to facilitate business-to-business used vehicle sales between a selling dealership (“Seller”) and a buying dealership (“Buyer”). Customers using the Marketplace are licensed automotive dealerships or other commercial automotive enterprises. At the election of the customer purchasing a vehicle, the Company can arrange third-party transportation services for the delivery of the purchased vehicle through its wholly owned subsidiary, ACV Transportation LLC. The Company can also provide the customer financing for the purchased vehicle through its wholly owned subsidiary, ACV Capital LLC. ACV also provides data services that offer insights into the condition and value of used vehicles for transactions both on and off our Marketplace, which help dealerships, their end customers, and commercial partners make more informed decisions to transact with confidence and efficiency. Customers using data services are licensed automotive dealerships or other commercial automotive enterprises. All services are provided in the United States and are supported by the Company’s operations which are in both the United States and Canada.
Basis of Consolidation	Basis of Consolidation — The consolidated financial statements include the accounts of ACV Auctions Inc. and all of its subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Basis of Preparation	Basis of Preparation — The accompanying unaudited interim consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and pursuant to the applicable rules and regulations of the Securities and Exchange Commission ("SEC"). The Company has condensed or omitted certain information and notes normally included in complete annual financial statements prepared in accordance with GAAP. These financial statements have been prepared on the same basis as the Company's annual financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments, which are necessary for the fair statement of the Company's financial information. The unaudited interim consolidated financial statements should therefore be read in conjunction with the audited consolidated financial statements and accompanying notes included in Form 424B4 ("Prospectus"), filed with the SEC on March 24, 2021. Any reference in these notes to applicable guidance is meant to refer to the authoritative GAAP as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Update (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Initial Public Offering	Initial Public Offering — On March 26, 2021, the Company completed its initial public offering (“IPO”), in which the Company issued and sold 16,550,000 shares of its Class A common stock at a public offering price of $ 25.00 per share, which resulted in net proceeds of $ 388.9 million after deducting underwriting discounts and commissions. On March 26, 2021, the underwriters exercised their option to purchase an additional 2,482,500 shares of Class A common stock at $ 25.00 per share from selling stockholders identified in the Prospectus. The Company did no t receive any of the proceeds from the sale of any shares of Class A common stock by the selling stockholders upon such exercise. Immediately prior to the closing of the IPO, all shares of common stock then outstanding were reclassified as Class B common stock and all shares of the convertible preferred stock then outstanding automatically converted into 115,269,221 shares of Class B common stock. Prior to the IPO, deferred offering costs, which consist of direct incremental legal, accounting, and consulting fees relating to the IPO, were capitalized in prepaid expenses and other current assets in the condensed consolidated balance sheets. Upon the consummation of the IPO, $ 3.9 million of net deferred offering costs were reclassified into stockholders’ equity as an offset against IPO proceeds.
Emerging Growth Company	Emerging Growth Company —The Company is an “emerging growth company,” as defined in Section 2(a) of the Securities Act of 1933, as amended (the "Securities Act"), as modified by the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”), and it may take advantage of certain exemptions from various reporting requirements that are applicable to other public companies that are not emerging growth companies including, but not limited to, not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act, reduced disclosure obligations regarding executive compensation in its periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and shareholder approval of any golden parachute payments not previously approved. Further, Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a Securities Act registration statement declared effective or do not have a class of securities registered under the Securities Exchange Act of 1934, as amended (“Exchange Act”)) are required to comply with the new or revised financial accounting standards. The JOBS Act provides that a company can elect to opt out of the extended transition period and comply with the requirements that apply to non-emerging growth companies but any such election to opt out is irrevocable. The Company has elected not to opt out of such extended transition period which means that when a standard is issued or revised and it has different application dates for public or private companies, the Company, as an emerging growth company, can adopt the new or revised standard at the time private companies adopt the new or revised standard. This may make comparison of the Company’s financial statements with another public company which is neither an emerging growth company nor an emerging growth company which has opted out of using the extended transition period difficult or impossible because of the potential differences in accounting standards used.
Stock-Based Compensation	Stock-Based Compensation— The Company uses the fair value recognition provisions of ASC 718, Compensation – Stock Compensation . The estimated fair value of each Common Stock option award is calculated on the date of grant using the Black-Scholes option pricing model. Application of the Black-Scholes option pricing model requires significant judgment, and involves the use of subjective assumptions including: Expected Term —The expected term represents the period that the stock-based awards are expected to be outstanding. As the Company does not have sufficient historical experience for determining the expected term of the stock option awards granted, the simplified method was used to determine the expected term for awards issued to employees. Risk-Free Interest Rate —The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the date of grant for zero-coupon U.S. Treasury constant maturity notes with terms approximately equal to the stock-based awards’ expected term. Expected Volatility —Since the Company is newly public and does not have a trading history of common stock, the expected volatility is derived from the average historical volatilities of the common stock of several public companies considered to be comparable to the Company over a period equivalent to the expected term of the stock-based awards. Dividend Rate —The expected dividend rate is zero as the Company has not paid and does not anticipate paying any dividends in the foreseeable future. Fair Value of Common Stock —Prior to the IPO, the Company estimated the fair value of common stock. The Board of Directors, with input from management, considered numerous objective and subjective factors to determine the fair value of the Company’s common stock at each meeting in which awards were approved. Subsequent to the IPO, the fair value of the underlying common stock is determined by the closing price, on the date of grant, of the Company’s Class A common stock, which is traded publicly on the Nasdaq Global Select Market. The Company measures all stock options and other stock-based awards granted to employees, directors, consultants and other nonemployees based on the fair value on the date of the grant. The options vest based on a graded scale over the stated vesting period, and compensation expense is recognized based on their grant date fair value on a straight-line basis over the vesting period. Forfeitures are recognized as they occur. The fair value of restricted stock awards and units are determined based on the estimated market price of the Company’s Common Stock on the grant date. The awards and units vest over time and compensation expense is recognized based on their grant date fair value ratably over the vesting period. The Company classifies stock-based compensation expense in its Condensed Consolidated Statements of Operations in the same way the payroll costs or service payments are classified for the related stock-based award recipient.
Marketplace and Service Revenue	Marketplace and Service Revenue— As described in Note 12, the Company acquired Max Digital LLC ("Max Digital") on July 12, 2021. Through Max Digital, the Company generates data services revenue from software related services. Subscription revenue is recognized on a ratable basis over the contractual subscription term of the arrangement, as the underlying service is a stand-ready performance obligation, beginning on the date that our services are made available to the customer. Implementation and training revenue is recognized over time as services are transferred to our customers.
Accounting Pronouncements	Accounting Pronouncements— The following table provides a description of accounting standards that were adopted by the Company as well as standards that are not yet adopted that could have an impact to the consolidated financial statements upon adoption. Accounting Standard Update Description Required Effect on consolidated Accounting Standards Adopted Simplifying the Accounting for Income Taxes (ASU 2019-12) The guidance simplifies the accounting for income taxes by removing certain exceptions to the general principles in ASC 740. January 1, 2022 Early adoption permitted The guidance was early adopted on January 1, 2021 on a prospective basis and did not have a material impact to the consolidated financial statements. Accounting Standards Not Yet Adopted Measurement of Credit Losses on Financial Instruments (ASU 2016-13, 2018-19, 2019-04, 2019-05, 2019-10, 2019-11, 2020-02, 2020-03) The guidance changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. January 1, 2023 Early adoption permitted The Company is currently evaluating the impact this guidance may have on the consolidated financial statements. The Company reviewed all other recently issued accounting standards and concluded that they were not applicable to the consolidated financial statements.

Accounts Receivables & Allowa_2

Accounts Receivables & Allowance for Doubtful Receivables (Tables)	9 Months Ended
	Sep. 30, 2021
Accounts Receivable Net [Abstract]
Summary of changes in the Allowance for Doubtful Trade Receivables	Changes in the allowance for doubtful trade receivables for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Beginning balance 3,158 $ 2,282 $ 2,092 $ 1,352 Provision for bad debt 676 781 2,119 4,380 Net write-offs Write-offs ( 1,193 ) ( 2,013 ) ( 3,951 ) ( 5,423 ) Recoveries 393 1,132 2,774 1,873 Net write-offs ( 800 ) ( 881 ) ( 1,177 ) ( 3,550 ) Ending balance $ 3,034 $ 2,182 $ 3,034 $ 2,182
Summary of changes in the Allowance for Doubtful Finance Receivables	Changes in the allowance for doubtful finance receivables for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Beginning balance $ 96 $ 40 $ 40 $ 65 Provision for bad debt 253 4 399 75 Net write-offs Write-offs ( 96 ) ( 4 ) ( 186 ) ( 100 ) Recoveries 14 - 14 - Net write-offs ( 83 ) ( 4 ) ( 173 ) ( 100 ) Ending balance $ 266 $ 40 $ 266 $ 40

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Outstanding Long-Term Debt	The Company’s outstanding long-term debt consisted of the following at September 30, 2021 and December 31, 2020 (in thousands): September 30, December 31, Interest Rate * Maturity Date * 2021 2020 2019 Revolver LIBOR + 3.75% June 25, 2024 $ 500 $ 4,832 Total long-term debt $ 500 $ 4,832 * The interest rate and maturity date presented in the table above represent the rate and maturity date in place as of September 30, 2021

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue From Contract With Customer [Abstract]
Summary of disaggregation of revenue	The following table summarizes the primary components of revenue, this level of disaggregation takes into consideration how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors (in thousands): Three months ended September 30, For the nine months ended September 30, 2021 2020 2021 2020 Auction marketplace revenue $ 40,006 $ 32,776 $ 120,863 $ 74,139 Transportation, data, and other services 39,300 23,591 100,769 55,134 Marketplace and service revenue $ 79,306 $ 56,367 $ 221,632 $ 129,273

Stock-Based Employee Compensa_2

Stock-Based Employee Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following table summarizes the stock option activity for the nine months ended September 30, 2021 (in thousands, except for share and per share amounts): Number of Weighted- Intrinsic Weighted- Outstanding, December 31, 2020 9,933,348 $ 2.16 $ 129,358 7.80 Granted 633,700 8.10 Exercised ( 1,073,448 ) 1.02 Forfeited ( 169,975 ) 4.46 Expired ( 38,111 ) 2.08 Outstanding, September 30, 2021 9,285,514 $ 2.66 $ 141,393 7.23 Exercisable, September 30, 2021 5,574,039 $ 1.24 $ 92,813 6.32 Expected to Vest, September 30, 2021 3,711,475 $ 4.79 $ 48,579 8.60
Summary of restricted stock unit activity	The following table summarizes the restricted stock unit activity for the nine months ended September 30, 2021 (in thousands, except for share and per share amounts): Number of RSUs Weighted- Outstanding, December 31, 2020 250,000 $ 10.52 Granted 3,178,671 22.10 Vested ( 178,513 ) 17.83 Forfeited ( 10,260 ) 22.46 Outstanding, September 30, 2021 3,239,898 $ 21.44

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Basic And Diluted Net Earnings (Loss) Per Share	The numerators and denominators of the basic and diluted net income (loss) per share computations for the Company's common stock are calculated as follows for the three and nine months ended September 30, 2021 and 2020 (in thousands, except share data): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Class A Class B Class A Class B Numerator: Net income (loss) attributable to common $ ( 9,202 ) $ ( 15,601 ) $ 3,159 $ ( 13,064 ) $ ( 38,806 ) $ ( 28,762 ) Denominator: Weighted-average number of shares of common 57,516,336 97,521,575 21,742,708 28,982,025 86,093,005 21,437,785 Dilutive effect of convertible preferred stock - - 112,056,011 - - - Dilutive effect of assumed conversion of options - - 5,299,908 - - - Dilutive effect of assumed conversion of - - 142,060 - - - Weighted-average number of shares of common 57,516,336 97,521,575 139,240,687 28,982,025 - 86,093,005 21,437,785 Net income (loss) per share attributable to $ ( 0.16 ) $ ( 0.16 ) $ 0.15 $ ( 0.45 ) $ ( 0.45 ) $ ( 1.34 ) Net income (loss) per share attributable to $ ( 0.16 ) $ ( 0.16 ) $ 0.02 $ ( 0.45 ) $ ( 0.45 ) $ ( 1.34 )
Summary of Potentially Dilutive Shares Excluded from Computation of Net Loss Per Share	The following table presents the total weighted-average number of potentially dilutive shares that were excluded from the computation of diluted net loss per share attributable to common stockholders because their effect would have been anti-dilutive for the period presented: Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Convertible Preferred Stock Series Seed I, Seed II, - - - 111,106,946 Unvested RSAs and RSUs 281,082 - 381,656 321,609 Stock options not subject to performance 7,440,345 - 7,950,194 5,653,104

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Summary of the assets acquired and liabilities assumed	The aggregate purchase price was preliminarily allocated to the assets acquired and liabilities assumed as follows (in thousands): Assets Acquired Cash and cash equivalents 1,458 Trade receivables 1,673 Other current assets 448 Property & equipment, net 30 Goodwill and intangible assets 60,918 Total assets acquired $ 64,527 Liabilities Assumed Accounts payable 1,084 Accrued payroll 616 Accrued other liabilities 252 Deferred Revenue 1,186 Total liabilities assumed 3,138 Net assets acquired $ 61,389

Nature of Business and Summary

Nature of Business and Summary of Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Thousands	Mar. 26, 2021USD ($)$ / sharesshares	Sep. 30, 2021IndustrySegmentshares
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of operating segments | IndustrySegment		1
Deferred offering costs, net | $	$ 3,900
Common Class A [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Shares offering, price per share | $ / shares	$ 25
Option to purchase additional shares of common stock | shares	2,482,500
Common Class B [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of shares issued upon conversion | shares	115,269,221
IPO | Common Class A [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Issuance of common stock in connection with initial public offering, net of underwriting discounts and commissions and other offering costs, Shares | shares	16,550,000	16,550,000
Shares offering, price per share | $ / shares	$ 25
Proceeds from issuance of initial public offering | $	$ 388,900
Proceeds from issuance of initial public offering by selling shareholders | $	$ 0

Accounts Receivables & Allowa_3

Accounts Receivables & Allowance for Doubtful Receivables - Summary of changes in the Allowance for Doubtful Trade Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounts Receivable Net [Abstract]
Beginning balance	$ 3,158	$ 2,282	$ 2,092	$ 1,352
Provision for bad debt	676	781	2,119	4,380
Write-offs	(1,193)	(2,013)	(3,951)	(5,423)
Recoveries	393	1,132	2,774	1,873
Net write-offs	(800)	(881)	(1,177)	(3,550)
Ending balance	$ 3,034	$ 2,182	$ 3,034	$ 2,182

Accounts Receivables & Allowa_4

Accounts Receivables & Allowance for Doubtful Receivables - Summary of changes in the Allowance for Doubtful Finance Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accounts Receivable Net [Abstract]
Beginning balance	$ 96	$ 40	$ 40	$ 65
Provision for bad debt	253	4	399	75
Write-offs	(96)	(4)	(186)	(100)
Recoveries	14	0	14	0
Net write-offs	(83)	(4)	(173)	(100)
Ending balance	$ 266	$ 40	$ 266	$ 40

Guarantees, Commitments and C_2

Guarantees, Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Commitments And Contingencies [Line Items]
Guarantee term	10 days
Sale price of vehicles with outstanding guarantee	$ 284	$ 95.7
Accrued Other Liabilities [Member]
Commitments And Contingencies [Line Items]
Carrying amount of the liability	1.5	1
Recognized probable loss contingency	$ 1	$ 1.1

Borrowings -Schedule of Outstan

Borrowings -Schedule of Outstanding Long-Term Debt (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total long-term debt	$ 500	$ 4,832
2019 Revolver [Member]
Debt Instrument [Line Items]
Maturity Date	Jun. 25, 2024
Total long-term debt	$ 500	$ 4,832
2019 Revolver [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest rate description	LIBOR + 3.75%

Borrowings - Additional Informa

Borrowings - Additional Information (Details) - USD ($) $ in Millions	Aug. 24, 2021	Jun. 25, 2021	Sep. 30, 2021	Dec. 31, 2020
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Outstanding borrowings			$ 0.5	$ 4.8
2019 Revolver [Member]
Debt Instrument [Line Items]
Maturity Date			Jun. 25, 2024
Unused borrowing capacity			$ 49.5
Revolving feature end date			Jun. 25, 2023
Interest rate			4.75%
2019 Revolver [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest rate description			LIBOR + 3.75%
2019 Revolver [Member] | First Amendment to Loan and Security Agreement [Member]
Debt Instrument [Line Items]
Maximum principal amount		$ 50
Maturity Date		Jun. 25, 2024
2019 Revolver [Member] | First Amendment to Loan and Security Agreement [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest Rate		3.75%
2021 Revolver [Member]
Debt Instrument [Line Items]
Maximum principal amount	$ 160
Maturity Date	Aug. 24, 2026
Commitment fee percentage	0.25%
Outstanding letter of credit issued			$ 0.5
2021 Revolver [Member] | LIBOR [Member]
Debt Instrument [Line Items]
Interest rate description	LIBOR (or a replacement rate established in accordance with the terms of the credit agreement) (subject to a 0.00% LIBOR floor), plus a margin of 2.75% per annum
2021 Revolver [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Interest rate description	the Alternative Base Rate plus a margin of 1.75% per annum
2021 Revolver [Member] | Alternative Base Rate Highest [Member]
Debt Instrument [Line Items]
Interest rate description	(a) the Wall Street Journal prime rate, (b) the NYFRB rate plus 0.5%, and (c)(i) 1.00% plus (ii) the adjusted LIBOR rate for a one-month interest period.
Letter Of Credit [Member]
Debt Instrument [Line Items]
Maximum principal amount	$ 20

Convertible Preferred Stock a_2

Convertible Preferred Stock and Stockholders' Deficit - Additional Information (Details) - shares	Mar. 26, 2021	Sep. 30, 2021	Sep. 30, 2021
Class Of Stock [Line Items]
Convertible preferred stock shares outstanding	0
Common stock, voting rights			The Class A common stock is entitled to one vote per share and the Class B common stock is entitled to ten votes per share.
Common Class B [Member]
Class Of Stock [Line Items]
Number of shares issued upon conversion	115,269,221
Common stock, shares authorized		160,000,000	160,000,000
Conversion of shares		49,257,842	70,310,049
Convertible Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, conversion basis	one-for-one basis
Common Class A [Member]
Class Of Stock [Line Items]
Common stock, shares authorized		2,000,000,000	2,000,000,000

Revenue - Summary of primary co

Revenue - Summary of primary component of Revenue, Level of Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Auction Marketplace Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 40,006	$ 32,776	$ 120,863	$ 74,139
Transportation Data And Other Services Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	39,300	23,591	100,769	55,134
Marketplace And Service Revenue [Member]
Disaggregation Of Revenue [Line Items]
Revenue	$ 79,306	$ 56,367	$ 221,632	$ 129,273

Stock-Based Employee Compensa_3

Stock-Based Employee Compensation- Additional Information (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Restricted Stock Units and Common Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Compensation expense related to restricted stock	$ 84
Weighted average period of recognized term	2 years 4 months 20 days	3 years 5 months 26 days
Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance	12,719,849

Stock-Based Employee Compensa_4

Stock-Based Employee Compensation - Summary of Stock Option Activity (Details) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Share Based Compensation [Abstract]
Number of options, outstanding, December 31, 2020 | shares	9,933,348
Number of options, granted | shares	633,700
Number of options, exercised | shares	(1,073,448)
Number of options, forfeited | shares	(169,975)
Number of options, expired | shares	(38,111)
Number of options, outstanding, September 30, 2021 | shares	9,285,514	9,933,348
Number of options, exercisable, September 30, 2021 | shares	5,574,039
Number of options, expected to vest, September 30, 2021 | shares	3,711,475
Weighted-average exercise price per share, outstanding, December 31, 2020 | $ / shares	$ 2.16
Weighted-average exercise price per share, granted | $ / shares	8.10
Weighted-average exercise price per share, exercised | $ / shares	1.02
Weighted-average exercise price per share, forfeited | $ / shares	4.46
Weighted-average exercise price per share, expired | $ / shares	2.08
Weighted-average exercise price per share, outstanding, September 30, 2021 | $ / shares	2.66	$ 2.16
Weighted-average exercise price per share, exercisable, September 30, 2021 | $ / shares	1.24
Weighted-average exercise price per share, expected to vest, September 30, 2021 | $ / shares	$ 4.79
Intrinsic value, outstanding, December 31, 2020 | $	$ 129,358
Intrinsic value, outstanding, September 30, 2021 | $	141,393	$ 129,358
Intrinsic value, exercisable, September 30, 2021 | $	92,813
Intrinsic value, expected to vest, September 30, 2021 | $	$ 48,579
Weighted Average Remaining Contractual Term, Outstanding	7 years 2 months 23 days	7 years 9 months 18 days
Weighted Average Remaining Contractual Term, Exercisable	6 years 3 months 25 days
Weighted Average Remaining Contractual Term, Expected to Vest	8 years 7 months 6 days

Stock-Based Employee Compensa_5

Stock-Based Employee Compensation - Summary of restricted stock unit (Details) - Restricted Stock Units [Member]	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of RSUs Outstanding, December 31, 2020 | shares	250,000
Number of RSUs, Granted | shares	3,178,671
Number of RSUs, Vested | shares	(178,513)
Number of RSUs, Forfeited | shares	(10,260)
Number of RSUs Outstanding, September 30, 2021 | shares	3,239,898
Weighted-Average Grant-Date Fair Value Outstanding, December 31, 2020 | $ / shares	$ 10.52
Weighted-Average Grant-Date Fair Value, Granted | $ / shares	22.10
Weighted-Average Grant-Date Fair Value, Vested | $ / shares	17.83
Weighted-Average Grant-Date Fair Value, Forfeited | $ / shares	22.46
Weighted-Average Grant-Date Fair Value Outstanding, September 30, 2021 | $ / shares	$ 21.44

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Effective Income Tax	(0.00%)	8.00%	(1.00%)	(1.00%)

Fair Value Measurement - Additi

Fair Value Measurement - Additional Information (Details) - USD ($) $ in Millions	Sep. 30, 2021	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Assets, fair value disclosure	$ 0	$ 0
Fair value of guarantees	$ 0	$ 0

Net Income (Loss) Per Share - S

Net Income (Loss) Per Share - Schedule of Basic And Diluted Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net income (loss) attributable to common stockholders		$ 3,159		$ (28,762)
Weighted-average number of shares of common stock - basic	155,037,911	21,742,708	115,075,030	21,437,785
Dilutive effect of convertible preferred stock series Seed I, Seed II, A, B, C, D, E, and E1		112,056,011
Dilutive effect of assumed conversion of options to purchase common stock		5,299,908
Dilutive effect of assumed conversion of restricted stock awards and units		142,060
Weighted-average number of shares of common stock - diluted	155,037,911	139,240,687	115,075,030	21,437,785
Net income (loss) per share attributable to common stockholders - basic	$ (0.16)	$ 0.15	$ (0.45)	$ (1.34)
Net income (loss) per share attributable to common stockholders - diluted	$ (0.16)	$ 0.02	$ (0.45)	$ (1.34)
Common Class A [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net income (loss) attributable to common stockholders	$ (9,202)		$ (13,064)
Weighted-average number of shares of common stock - basic	57,516,336		28,982,025
Weighted-average number of shares of common stock - diluted	57,516,336		28,982,025
Net income (loss) per share attributable to common stockholders - basic	$ (0.16)		$ (0.45)
Net income (loss) per share attributable to common stockholders - diluted	$ (0.16)		$ (0.45)
Common Class B [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Net income (loss) attributable to common stockholders	$ (15,601)		$ (38,806)
Weighted-average number of shares of common stock - basic	97,521,575		86,093,005
Weighted-average number of shares of common stock - diluted	97,521,575		86,093,005
Net income (loss) per share attributable to common stockholders - basic	$ (0.16)		$ (0.45)
Net income (loss) per share attributable to common stockholders - diluted	$ (0.16)		$ (0.45)

Net Income (Loss) Per Share -_2

Net Income (Loss) Per Share - Summary of Potentially Dilutive Shares Excluded from Computation of Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of Net loss per share	0	0	0	111,106,946
Unvested RSAs and RSUs [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of Net loss per share	281,082	0	381,656	321,609
Employee Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of Net loss per share	7,440,345	0	7,950,194	5,653,104

Reverse Stock Split - Additiona

Reverse Stock Split - Additional Information (Details) $ in Thousands	Mar. 11, 2021USD ($)
Stockholders Equity Note [Abstract]
Reverse stock split,Converstion Ratio	1-for-2
Reverse stock split, Description	On March 11, 2021, the Board of Directors and the stockholders of the Company approved a 1-for-2 reverse stock split of the Company’s outstanding common stock and convertible preferred stock. All common stock, convertible preferred stock, and per share information have been retroactively adjusted to give effect to this reverse stock split for all periods presented. Shares of common stock underlying outstanding stock options, restricted stock units, and restricted stock awards were proportionately decreased and the retrospective per share value and exercise prices, if applicable, were proportionately increased in accordance with the terms of the agreements governing such securities. There were no changes in the par values of the Company’s common stock and convertible preferred stock as a result of the reverse stock split.
Reverse stock split effect on par value	$ 0

Acquisitions - Additional Infor

Acquisitions - Additional Information (Details) - USD ($) $ in Thousands	Jul. 12, 2021	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Compensation expense			$ 16,417	$ 3,473
Max Digital LLC
Business Acquisition [Line Items]
Date of acquisition	Jul. 12, 2021
Cash paid for business acquisition	$ 61,400
Acquisition transaction costs	$ 1,000
Name of acquired entity	Max Digital
Description of acquired entity	Max Digital is a pioneer in automotive data and merchandising products, and is best known for its flagship inventory management system platform. Max Digital's software products enable dealers to accurately price wholesale and retail inventory while maximizing profit on each vehicle sold by leveraging predictive analytics informed by machine learning.
Amortization Method			straight-line basis
Amortization Period			15 years
TruePartners USA LLC
Business Acquisition [Line Items]
Compensation expense		$ 3,400

Acquisitions - Schedule of Purc

Acquisitions - Schedule of Purchase Price Allocated To The Assets Acquired And Liabilities Assumed (Additional Information) (Details) - Max Digital LLC [Member] $ in Thousands	Sep. 30, 2021USD ($)
Assets Acquired
Cash and cash equivalents	$ 1,458
Trade receivables	1,673
Other current assets	448
Property & equipment, net	30
Goodwill and intangible assets	60,918
Total assets acquired	64,527
Liabilities Assumed
Accounts payable	1,084
Accrued payroll	616
Accrued other liabilities	252
Deferred Revenue	1,186
Total liabilities assumed	3,138
Net assets acquired	$ 61,389