Description of Business and Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation and ConsolidationThe Company has one reportable segment. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company, its wholly-owned subsidiaries, and consolidated variable interest entities (“VIEs”). All intercompany accounts and transactions have been eliminated. The Company’s functional and reporting currency is the U.S. dollar.
Basis of Consolidation	Basis of Presentation and ConsolidationThe Company has one reportable segment. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company, its wholly-owned subsidiaries, and consolidated variable interest entities (“VIEs”). All intercompany accounts and transactions have been eliminated. The Company’s functional and reporting currency is the U.S. dollar.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires that management make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Significant estimates and assumptions made in the accompanying consolidated financial statements, which Management believes are critical in understanding and evaluating the Company’s reported financial results include: (i) fair value determinations; (ii) stock-based compensation; (iii) consolidation of VIEs; and (iv) the evaluation for impairment of goodwill and acquired intangible assets. The Company bases its estimates on various factors it believes to be reasonable under the circumstances. Actual results could differ from those estimates and such differences could affect the results of operations reported in future periods.
Variable Interest Entities	Variable Interest Entities A legal entity is considered a VIE if it has either a total equity investment that is insufficient to finance its operations without additional subordinated financial support or whose equity holders lack the characteristics of a controlling financial interest. The Company’s variable interests arise from contractual, ownership, or other monetary interests in the entity. The Company consolidates a VIE when it is deemed to be the primary beneficiary. The Company determines it is the primary beneficiary if it has the power to direct activities that most significantly impact the VIE’s economic performance and has the obligation to absorb losses or the right to receive benefits of the VIE that could be potentially significant to the VIE. The Company assesses whether or not it is the primary beneficiary of a VIE on an ongoing basis. Consolidated VIEs The Company consolidates VIEs in which the Company has a variable interest and is determined to be the primary beneficiary. This determination is based on whether the Company has a variable interest (or combination of variable interests) that provides the Company with (a) the power to direct the activities that most significantly impact the VIE’s economic performance and (b) the obligation to absorb losses or right to receive benefits that could be potentially significant to the VIE. The Company continually reassesses whether it is the primary beneficiary of a VIE throughout the entire period the Company is involved with the VIE. The Company also determines whether decision-maker or service-provider fees are variable interests. Decision-maker or service-provider fees are not considered variable interests when the arrangement does not expose the Company to risks of loss that a potential VIE was designed to pass on to its variable interest holders, the fees are commensurate, the arrangement is at market, and the Company does not have any other interests (including direct interests and certain indirect interests held through related parties) that absorb more than an insignificant amount of a VIE’s potential variability. This determination can have a significant impact on the Company’s consolidation analysis, as it could affect whether a legal entity is a VIE and whether the Company is the primary beneficiary of a VIE. When the Company’s decision-maker or service-provider fee is not a variable interest, the Company is viewed as acting as a fiduciary for the potential VIE. Unconsolidated VIEs The Company’s transactions with unconsolidated VIEs include securitizations of unsecured personal whole loans and sales of whole loans to VIEs. While the Company continues to be involved with the unconsolidated VIEs in its role as the sponsor and the servicer of these transactions, the Company does not hold a significant economic interest in these entities and has determined that it is not the primary beneficiary of these entities. The Company’s unconsolidated VIEs include entities established as the issuers and grantor trusts for various securitization transactions. In cases where the VIEs are not consolidated and the transfer of the loans from the Company to the securitization trust meets sale accounting criteria, the Company recognizes a gain or loss on sales of loans. The net proceeds of the sale represent the fair value of any assets obtained or liabilities incurred as part of the transaction. The assets are transferred into a trust such that the assets are legally isolated from the creditors of the Company and are not available to satisfy obligations of the Company. These assets can only be used to settle obligations of the underlying securitization trusts.
Cash and Restricted Cash	Cash and Restricted Cash Cash consists of bank deposits held in business checking and interest-bearing deposit accounts. As of December 31, 2021 and 2022, the Company did not have any cash equivalent balances, defined as highly liquid financial instruments purchased with original maturities of three months or less. Restricted cash primarily consists of deposit accounts that are held in our custody but restricted for regulatory or legal purposes. This balance includes amounts that are: (i) received from borrowers for interest and principal applied to loans as part of loan servicing, but not yet distributed to institutional investors; (ii) collateral for financing of loan purchases on the Upstart platform; (iii) purchase price received from institutional investors; (iv) collateral for letters of credit the Company is required to maintain under its operating lease agreements; and (v) pledged collateral under the Company’s warehouse facilities.
Fair Value Measurement	Fair Value Measurement 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. The price used to measure fair value is not adjusted for transaction costs. The principal market is the market in which the Company would sell or transfer the asset with the greatest volume and level of activity for the asset. In determining the principal market for an asset or liability, it is assumed that the Company has access to the market as of the measurement date. If no market for the asset exists, or if the Company does not have access to the principal market, a hypothetical market is used. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: Level 1—Unadjusted quoted market prices in active markets for identical assets or liabilities; Level 2— Inputs (other than quoted prices 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; and 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. Assets and liabilities measured at fair value on a recurring basis include loans, notes receivable and residual certificates, loan servicing assets and liabilities, and trailing fee liabilities. When developing fair value measurements, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs. However, for certain instruments, the Company must utilize unobservable inputs in determining fair value due to the lack of observable inputs in the market, which requires greater judgment in measuring fair value. In instances where there is limited or no observable market data, fair value measurements for assets and liabilities are based primarily upon the Company’s own estimates, and the measurements reflect information and assumptions that management believes a market participant would use in pricing the asset or liability.
Financial Instruments not Measured at Fair Value	Financial Instruments not Measured at Fair Value The Company’s financial instruments not measured at fair value consist primarily of cash, restricted cash, and other assets (excluding certain financial instruments, which are measured at fair value, such as loan servicing assets), accounts payable, payable to investors, and other liabilities (excluding certain financial instruments, such as loan servicing liabilities and trailing fee liabilities which are measured at fair value). Payable to investors includes amounts of loan repayments not yet distributed to institutional investors, as well as amounts received from institutional investors but not yet invested directly in whole loans or notes payable. The carrying values of these financial instruments are approximates of their respective fair values due to their short-term nature. Borrowings are presented at par, net of debt issuance costs and amortized over the contractual term using the effective interest method, with accrued interest included as part of accrued expenses and other liabilities on the consolidated balance sheets. The carrying value of borrowings associated with the warehouse credit facilities and risk retention funding loans approximates the fair value due to their relatively short maturities. The estimated fair value of the Notes as of December 31, 2021 and 2022 was approximately $627.5 million and $364.8 million, respectively, which represent Level 2 valuations in the fair value hierarchy. The estimated fair value was determined based on the estimated or actual bids and offers of the Notes in an over-the-counter market.
Transfer of Financial Assets	Transfer of Financial AssetsUpstart-powered loans originated by lending partners are either retained by the lending partners, purchased by the Company and immediately sold to institutional investors under loan sale agreements, or purchased and held by the Company for a period of time before being sold to third-party investors, or held to maturity by the Company for the primary purpose of product research and development. Loans retained and held on the Company’s consolidated balance sheets are classified as either held-for-investment or held-for-sale, and loans purchased for immediate resale to third-party investors are classified as held-for-sale. Immediate loan resales to institutional investors are accounted for as transfers of financial assets when the Company surrenders control of these loan assets. These sales typically occur shortly after the origination of the loans by the lending partner and the Company’s subsequent acquisition of the loans from the originating lending partner. Loans sold to institutional investors are derecognized from the Company’s consolidated balance sheets at the time of sale in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-11 Topic 860, Transfers and Servicing. The Company records an asset or a liability at fair value for its estimated post-sale servicing obligations. The Company also records liabilities net of fair value for contingent obligations to repurchase loans that do not conform to the representations and warranties made to the loan purchaser at the time of sale. These liabilities are included within other liabilities on the Company’s consolidated balance sheets.
Loan Servicing Assets and Liabilities	Loan Servicing Assets and Liabilities Loan servicing assets and liabilities are recognized at fair value when the Company transfers loans, which qualify as sales under Topic 860 with servicing rights retained or when the Company enters into servicing agreements with lending partners who retain Upstart-powered loans. A loan servicing asset or liability exists depending on whether the revenue from servicing is expected to more than adequately compensate the Company for carrying out its servicing obligations. Loan servicing assets and liabilities are recorded in other assets and other liabilities, respectively, in the consolidated balance sheets, with changes in fair value recorded in servicing revenue, net, which is part of revenue from fees, net in the consolidated statements of operations and comprehensive income (loss).
Property, Equipment, and Software, Net	Property, Equipment, and Software, Net Property, equipment, and software are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line method over the estimated useful lives of the assets, which are generally three years for internally developed software, computer and networking equipment, and furniture and fixtures. Leasehold improvements are depreciated over the shorter of the remaining lease term or the estimated useful life.
Internally Developed Software	Internally developed software is capitalized upon completion of the preliminary project stage, when it becomes probable that the project will be completed, and the software will be used as intended. Capitalized costs primarily consist of salaries and payroll related costs for employees directly involved in development efforts. Costs related to the preliminary project stage and activities occurring after the implementation of the software are expensed as incurred. Costs incurred for software upgrades are capitalized if they result in additional functionalities or substantial enhancements.
Impairment of Long-Lived Assets	The Company evaluates its long-lived assets for potential impairment when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. When such an event occurs the carrying amount of the asset is reduced to its estimated fair value.
Leases	Leases The Company determines if an arrangement is or contains a lease at inception. Operating leases are recorded on the consolidated balance sheets with right-of-use assets representing the right to use the underlying asset and lease liabilities representing the obligation to make lease payments. Right-of-use assets (“ROU”) and lease liabilities are recognized at lease commencement primarily based on the present value of lease payments over the lease term, and as necessary, at modification. The operating lease ROU assets also include any initial direct costs, lease payments made prior to lease commencement, and lease incentives received. Variable lease payments are expensed as incurred and are not included within the ROU asset and lease liability calculation. Variable lease payments primarily include reimbursements of costs incurred by lessors for common area maintenance and utilities. The Company’s lease terms are the non-cancelable period including any rent-free periods provided by the lessor and may include options to extend or terminate the lease when it is reasonably certain that it will exercise that option. At lease inception, and in subsequent periods as necessary, the Company estimates the lease term based on its assessment of extension and termination options that are reasonably certain to be exercised. Lease costs for lease payments are recognized on a straight-line basis over the lease term. As the rate implicit on the Company’s leases is not readily determinable, the Company uses its secured incremental borrowing rate to determine the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term and in a similar economic environment. As of December 31, 2021 and 2022, the Company did not have any material finance leases. The Company has elected not to separate lease and non-lease components for any leases within its existing classes of assets and, as a result, accounts for any lease and non-lease components as a single lease component. The Company has immaterial leases with a term of 12 months or less.
Revenue Recognition	Revenue RecognitionThe Company’s revenue consists of two components: revenue from fees, net and interest income and fair value adjustments, net. The revenue from fees, net line item on the consolidated statements of operations and comprehensive income (loss) is primarily comprised of platform and referral fees, net, which are recognized based on FASB ASU 2014-09 Topic 606, Revenue from Contracts with Customers.
Operating Expenses	Operating Expenses Sales and marketing Sales and marketing expenses primarily consist of costs incurred across various advertising channels, including expenses for partnerships with third-parties providing borrower referrals, direct mail and digital advertising campaigns, as well as other expenses associated with building overall brand awareness and experiential marketing costs. Sales and marketing expenses also include payroll and other personnel-related costs, including stock-based compensation expense, for related teams. These costs are recognized in the period incurred. Customer operations Customer operations expenses include payroll and other personnel-related expenses, including stock-based compensation expense, for personnel engaged in onboarding, loan servicing, customer support and other related operational teams. These costs also include costs of third-party collection agencies and other systems and tools the Company uses as part of information verification, fraud detection, and payment processing activities. These costs are recognized in the period incurred. Engineering and product development Engineering and product development expenses primarily consist of payroll and other employee-related expenses, including stock-based compensation expenses, for the engineering and product development teams as well as the costs of systems and tools used by these teams. These costs are recognized in the period incurred. General, administrative, and other General, administrative, and other expenses consist primarily of payroll and other employee-related expenses, including stock-based compensation expense for legal and compliance, finance and accounting, human resources and facilities teams, as well as depreciation and amortization of property, equipment and software, professional services fees, facilities and travel expenses. These costs are recognized in the period incurred.
Stock-Based Compensation	Stock-Based Compensation The Company issues stock options, restricted stock units (“RSUs”), performance-based restricted stock units (“PRSUs”), and restricted stock to employees and non-employees, including directors and third-party service providers, and employee stock purchase rights granted under the Company’s employee stock purchase plan (“ESPP”). Stock options and employee stock purchase rights granted under the ESPP are initially measured at fair value at the date of grant using the Black-Scholes option-pricing model. RSUs and restricted stock are measured at the fair market value of our common stock at the grant date. PRSUs are initially measured at fair value using a Monte Carlo simulation model. Stock-based compensation expenses are recognized based on their respective grant-date fair values. Forfeitures are estimated at the time of grant and revised, as necessary, in subsequent periods if actual forfeitures differ from initial estimates. Stock-based compensation expense is recorded net of estimated forfeitures, such that the expense is recorded only for those awards that are expected to vest.
Business Combinations	Business Combinations The Company accounts for business combinations using the acquisition method of accounting which requires the fair values of assets acquired and liabilities assumed to be recognized in the consolidated financial statements. Assets acquired and liabilities assumed in a business combination are recognized at their estimated fair value as of the acquisition date. The excess purchase price over the fair value of assets acquired and liabilities assumed is recorded as goodwill. The allocation of fair values may be subject to adjustment after the initial allocation for up to a one-year period, with the corresponding offset to goodwill. Acquisition-related costs, such as legal and consulting fees, are recognized separately from the business combination and are expensed as incurred.
Non-marketable Equity Security	Non-marketable Equity Securities The Company’s strategic investments consists of non-marketable equity securities on the consolidated balance sheets which are investments in privately held companies. Non-marketable equity securities do not have a readily determinable fair value and are measured by the Company at cost less impairment, if any, and adjusted for changes resulting from observable price changes in orderly transactions for an identical or similar investment in the same issuer (the “measurement alternative”). Gains and losses on the investment, realized and unrealized, are recognized in other income (expense), net on our consolidated statements of operations and comprehensive income (loss) and a new carrying value is established for the investment upon such recognition of the gains and losses. There have been no unrealized or realized gains and losses or impairments related to the non-marketable equity securities accounted for under the measurement alternative for the years presented. As of December 31, 2021 and 2022, the carrying value of our non-marketable equity securities was $40.0 million and $41.3 million respectively. The determination of whether an orderly transaction is for an identical or similar investment requires significant management judgment. In its evaluation, the Company considers factors such as differences in the rights and preferences of the investment and the extent to which those differences would affect the fair value of the investment. In the event the Company identifies an observable price change from an orderly transaction for an identical or similar investment of the same issuer, the Company must estimate the fair value of its strategic investments using the most recent data available. The Company’s impairment analysis encompasses an assessment of both qualitative and quantitative factors.
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill represents the excess of the purchase price over the fair value of identifiable net assets acquired. Goodwill is reviewed for impairment annually, or more frequently if an event or a change in circumstances indicates that goodwill may be impaired. We first assess qualitative factors to determine if it is more likely than not that the fair value of the reporting unit is less than its carrying value. Examples of qualitative factors include, but are not limited to, a significant adverse change in legal factors or in the business climate, a significant decline in our stock price, a significant decline in our projected revenue or cash flows, or the presence of other indicators that would indicate a reduction in the fair value of a reporting unit. If the Company concludes that it is more likely than not that the fair value of the reporting unit is less than its carrying value, a quantitative test is performed. We perform a quantitative goodwill impairment test by determining the fair value of the reporting unit and comparing it to the carrying value of the reporting unit. If the fair value of the reporting unit is greater than the reporting unit’s carrying value, then the carrying value of the reporting unit is deemed to be recoverable. If the carrying value of the reporting unit is greater than the reporting unit’s fair value, goodwill is impaired and written down to the reporting unit’s fair value. Acquired intangible assets are recorded at fair value on the date of acquisition and amortized on a straight-line basis over their estimated useful lives. Acquired intangible assets are presented net of accumulated amortization on the consolidated balance sheets. The Company reviews the carrying amounts of intangible assets for impairment whenever an event or change in circumstances indicates that the carrying amount of the assets may not be recoverable. We measure the recoverability of intangible assets by comparing the carrying amount of each asset to the future undiscounted cash flows we expect the asset to generate. Impairment is measured by the amount in which the carrying value of the asset exceeds its fair value. In addition, we periodically evaluate the estimated remaining useful lives of long-lived intangible assets to determine whether events or changes in circumstances warrant a revision to the remaining period of amortization.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance may be established to reduce the deferred tax asset to the level at which it is “more likely than not” that the tax asset or benefits will be realized. Realization of tax benefits of deductible temporary differences and operating loss carryforwards depends on having sufficient taxable income of an appropriate character within the carry back or carryforward periods. The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon review by the taxing authority. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.
Other Income (Expense), Net	Other Income (Expense), Net In April 2020, the Company received a forgivable loan under the Paycheck Protection Program (“PPP”), totaling $5.3 million with a stated annual interest rate of 1%. All loan payments are deferred for six months if not forgiven under the provisions of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). The loan and accrued interest are forgivable for borrowers who use the loan proceeds for eligible expenses during a twenty-four week period following the borrower’s receipt of the loan and maintain payroll and employee headcount. The Company has used the full proceeds of the loan for eligible expenses within the required period. The Company determined that forgiveness of the loan under the CARES Act was reasonably assured and recorded the full amount of proceeds as other income in the consolidated statement of operations and comprehensive income (loss) in 2020. In March 2021, the Company voluntarily repaid proceeds received under the Paycheck Protection Program plus accrued interest totaling $5.3 million. The Company recognized the loan principal repayment as an other expense.
Net Income (Loss) Per Share Attributable to Common Stockholders of Upstart Holdings, Inc. Stockholders	Net Income (Loss) Per Share Attributable to Common Stockholders of Upstart Holdings, Inc. Stockholders The Company follows the two-class method when computing net income (loss) per common share when shares are issued that meet the definition of participating securities. The two-class method determines net income (loss) per common share for each class of common stock and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common stock and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. The Company’s convertible preferred stock contractually entitles the holders of such shares to participate in dividends but does not contractually require the holders of such shares to participate in the Company’s losses. Accordingly, for the periods where the Company is in a net loss position, the Company does not allocate any net loss attributable to common stockholders to the convertible preferred stock. Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted net income (loss) per share is the amount of net income (loss) available to each share of common stock outstanding during the reporting period, adjusted to include the effect of potentially dilutive common shares. Potentially dilutive common shares include incremental shares issued for convertible preferred stock, stock options, unvested RSUs, purchase rights committed under the ESPP, convertible debt, warrants to purchase convertible preferred stock and warrants to purchase common stock. The calculation of diluted net income (loss) per share excludes all anti-dilutive common shares. For periods in which the Company reports net losses, basic and diluted net loss per share attributable to Upstart Holdings, Inc.’s common stockholders are the same because potentially dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.
Recently adopted and issued accounting pronouncements	Recently Adopted Accounting Pronouncements The Company did not adopt any new accounting standard during the year ended December 31, 2022: Recently Issued Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting followed by ASU 2021-01, Reference Rate Reform, Scope issued in January 2021 and ASU 2022-06 in December 2022. ASU 2020-04, ASU 2021-01 and ASU 2022-06 provide temporary optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate or another reference rate expected to be discontinued because of reference rate reform, if certain criteria are met. The optional guidance in ASU 2020-04, ASU 2021-01, and ASU 2022-06 is effective for a limited period of time through December 31, 2024 and may be applied prospectively to contract modifications and hedging relationships. The Company does not expect the adoption of this guidance will have a material impact on the Company’s consolidated financial statements or related disclosures. In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. The new guidance requires contract assets and contract liabilities acquired in a business combination to be recognized and measured by the acquirer on the acquisition date in accordance with ASC 606, Revenue from Contracts with Customers, as if it had originated the contracts. Under the current business combinations guidance, such assets and liabilities are recognized by the acquirer at fair value on the acquisition date. The ASU is effective December 15, 2022, with early adoption permitted. The ASU is to be applied prospectively to business combinations occurring on or after the effective date of the amendment (or if adopted early as of an interim period, as of the beginning of the fiscal year that includes the interim period of early application). This standard has no impact on acquired contract assets or liabilities from business combinations occurring prior to the effective date of adoption. The Company does not expect the adoption of this guidance will have a material impact on the Company’s condensed consolidated financial statements or related disclosures.
Off-Balance Sheet Loans	Off-Balance Sheet Loans Off-balance sheet loans relate to securitization transactions for which the Company has some form of continuing involvement, including as servicer. For a loan related to securitization transactions where servicing is the only form of continuing involvement, the Company would only experience a loss if it were required to repurchase such a loan due to a breach in representations and warranties associated with its loan sale or servicing contracts. The Company routinely contributes loans to securitization transactions which it co-sponsors as a non-retaining sponsor. As a non-retaining sponsor and a servicer of these transactions, the Company does not retain economic risk in these transactions. Contributions of loans to these securitizations are recognized as transfers under ASC 860, Transfers and Servicing

Description of Business and Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

Basis of Presentation and ConsolidationThe Company has one reportable segment. The Company’s chief operating decision maker, the Chief Executive Officer, reviews financial information presented on a consolidated basis for purposes of allocating resources and evaluating financial performance. The accompanying consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and include the accounts of the Company, its wholly-owned subsidiaries, and consolidated variable interest entities (“VIEs”). All intercompany accounts and transactions have been eliminated. The Company’s functional and reporting currency is the U.S. dollar.

Basis of Consolidation

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires that management make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods.

Significant estimates and assumptions made in the accompanying consolidated financial statements, which Management believes are critical in understanding and evaluating the Company’s reported financial results include: (i) fair value determinations; (ii) stock-based compensation; (iii) consolidation of VIEs; and (iv) the evaluation for impairment of goodwill and acquired intangible assets. The Company bases its estimates on various factors it believes to be reasonable under the circumstances. Actual results could differ from those estimates and such differences could affect the results of operations reported in future periods.

Variable Interest Entities

A legal entity is considered a VIE if it has either a total equity investment that is insufficient to finance its operations without additional subordinated financial support or whose equity holders lack the characteristics of a controlling financial interest. The Company’s variable interests arise from contractual, ownership, or other monetary interests in the entity. The Company consolidates a VIE when it is deemed to be the primary beneficiary. The Company determines it is the primary beneficiary if it has the power to direct activities that most significantly impact the VIE’s economic performance and has the obligation to absorb losses or the right to receive benefits of the VIE that could be potentially significant to the VIE. The Company assesses whether or not it is the primary beneficiary of a VIE on an ongoing basis.

Consolidated VIEs

The Company consolidates VIEs in which the Company has a variable interest and is determined to be the primary beneficiary. This determination is based on whether the Company has a variable interest (or combination of variable interests) that provides the Company with (a) the power to direct the activities that most significantly impact the VIE’s economic performance and (b) the obligation to absorb losses or right to receive benefits that could be potentially significant to the VIE. The Company continually reassesses whether it is the primary beneficiary of a VIE throughout the entire period the Company is involved with the VIE.

The Company also determines whether decision-maker or service-provider fees are variable interests. Decision-maker or service-provider fees are not considered variable interests when the arrangement does not expose the Company to risks of loss that a potential VIE was designed to pass on to its variable interest holders, the fees are commensurate, the arrangement is at market, and the Company does not have any other interests (including direct interests and certain indirect interests held through related parties) that absorb more than an insignificant amount of a VIE’s potential variability. This determination can have a significant impact on the Company’s consolidation analysis, as it could affect whether a legal entity is a VIE and whether the Company is the primary beneficiary of a VIE. When the Company’s decision-maker or service-provider fee is not a variable interest, the Company is viewed as acting as a fiduciary for the potential VIE.

Unconsolidated VIEs

The Company’s transactions with unconsolidated VIEs include securitizations of unsecured personal whole loans and sales of whole loans to VIEs. While the Company continues to be involved with the unconsolidated VIEs in its role as the sponsor and the servicer of these transactions, the Company does not hold a significant economic interest in these entities and has determined that it is not the primary beneficiary of these entities. The Company’s unconsolidated VIEs include entities established as the issuers and grantor trusts for various securitization transactions.

In cases where the VIEs are not consolidated and the transfer of the loans from the Company to the securitization trust meets sale accounting criteria, the Company recognizes a gain or loss on sales of loans. The net proceeds of the sale represent the fair value of any assets obtained or liabilities incurred as part of the transaction. The assets are transferred into a trust such that the assets are legally isolated from the creditors of the Company and are not available to satisfy obligations of the Company. These assets can only be used to settle obligations of the underlying securitization trusts.

Cash and Restricted Cash

Cash consists of bank deposits held in business checking and interest-bearing deposit accounts. As of December 31, 2021 and 2022, the Company did not have any cash equivalent balances, defined as highly liquid financial instruments purchased with original maturities of three months or less.

Restricted cash primarily consists of deposit accounts that are held in our custody but restricted for regulatory or legal purposes. This balance includes amounts that are: (i) received from borrowers for interest and principal applied to loans as part of loan servicing, but not yet distributed to institutional investors; (ii) collateral for financing of loan purchases on the Upstart platform; (iii) purchase price received from institutional investors; (iv) collateral for letters of credit the Company is required to maintain under its operating lease agreements; and (v) pledged collateral under the Company’s warehouse facilities.

Fair Value Measurement

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. The price used to measure fair value is not adjusted for transaction costs. The principal market is the market in which the Company would sell or transfer the asset with the greatest volume and level of activity for the asset. In determining the principal market for an asset or liability, it is assumed that the Company has access to the market as of the measurement date. If no market for the asset exists, or if the Company does not have access to the principal market, a hypothetical market is used.

The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows:

Level 1—Unadjusted quoted market prices in active markets for identical assets or liabilities;

Level 2— Inputs (other than quoted prices 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; and

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.

Assets and liabilities measured at fair value on a recurring basis include loans, notes receivable and residual certificates, loan servicing assets and liabilities, and trailing fee liabilities. When developing fair value measurements, the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs.

However, for certain instruments, the Company must utilize unobservable inputs in determining fair value due to the lack of observable inputs in the market, which requires greater judgment in measuring fair value. In instances where there is limited or no observable market data, fair value measurements for assets and liabilities are based primarily upon the Company’s own estimates, and the measurements reflect information and assumptions that management believes a market participant would use in pricing the asset or liability.

Financial Instruments not Measured at Fair Value

The Company’s financial instruments not measured at fair value consist primarily of cash, restricted cash, and other assets (excluding certain financial instruments, which are measured at fair value, such as loan servicing assets), accounts payable, payable to investors, and other liabilities (excluding certain financial instruments, such as loan servicing liabilities and trailing fee liabilities which are measured at fair value). Payable to investors includes amounts of loan repayments not yet distributed to institutional investors, as well as amounts received from institutional investors but not yet invested directly in whole loans or notes payable. The carrying values of these financial instruments are approximates of their respective fair values due to their short-term nature.

Borrowings are presented at par, net of debt issuance costs and amortized over the contractual term using the effective interest method, with accrued interest included as part of accrued expenses and other liabilities on the consolidated balance sheets. The carrying value of borrowings associated with the warehouse credit facilities and risk retention funding loans approximates the fair value due to their relatively short maturities. The estimated fair value of the Notes as of December 31, 2021 and 2022 was approximately $627.5 million and $364.8 million, respectively, which represent Level 2 valuations in the fair value hierarchy. The estimated fair value was determined based on the estimated or actual bids and offers of the Notes in an over-the-counter market.

Transfer of Financial Assets

Transfer of Financial AssetsUpstart-powered loans originated by lending partners are either retained by the lending partners, purchased by the Company and immediately sold to institutional investors under loan sale agreements, or purchased and held by the Company for a period of time before being sold to third-party investors, or held to maturity by the Company for the primary purpose of product research and development. Loans retained and held on the Company’s consolidated balance sheets are classified as either held-for-investment or held-for-sale, and loans purchased for immediate resale to third-party investors are classified as held-for-sale. Immediate loan resales to institutional investors are accounted for as transfers of financial assets when the Company surrenders control of these loan assets. These sales typically occur shortly after the origination of the loans by the lending partner and the Company’s subsequent acquisition of the loans from the originating lending partner. Loans sold to institutional investors are derecognized from the Company’s consolidated balance sheets at the time of sale in accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Update (“ASU”) 2014-11 Topic 860, Transfers and Servicing. The Company records an asset or a liability at fair value for its estimated post-sale servicing obligations. The Company also records liabilities net of fair value for contingent obligations to repurchase loans that do not conform to the representations and warranties made to the loan purchaser at the time of sale. These liabilities are included within other liabilities on the Company’s consolidated balance sheets.

Loan Servicing Assets and Liabilities

Loan servicing assets and liabilities are recognized at fair value when the Company transfers loans, which qualify as sales under Topic 860 with servicing rights retained or when the Company enters into servicing agreements with lending partners who retain Upstart-powered loans. A loan servicing asset or liability exists depending on whether the revenue from servicing is expected to more than adequately compensate the Company for carrying out its servicing obligations.

Loan servicing assets and liabilities are recorded in other assets and other liabilities, respectively, in the consolidated balance sheets, with changes in fair value recorded in servicing revenue, net, which is part of revenue from fees, net in the consolidated statements of operations and comprehensive income (loss).

Property, Equipment, and Software, Net

Property, Equipment, and Software, Net Property, equipment, and software are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are recognized using the straight-line method over the estimated useful lives of the assets, which are generally three years for internally developed software, computer and networking equipment, and furniture and fixtures. Leasehold improvements are depreciated over the shorter of the remaining lease term or the estimated useful life.

Internally Developed Software

Internally developed software is capitalized upon completion of the preliminary project stage, when it becomes probable that the project will be completed, and the software will be used as intended. Capitalized costs primarily consist of salaries and payroll related costs for employees directly involved in development efforts. Costs related to the preliminary project stage and activities occurring after the implementation of the software are expensed as incurred. Costs incurred for software upgrades are capitalized if they result in additional functionalities or substantial enhancements.

Impairment of Long-Lived Assets

The Company evaluates its long-lived assets for potential impairment when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. When such an event occurs the carrying amount of the asset is reduced to its estimated fair value.

Leases

The Company determines if an arrangement is or contains a lease at inception. Operating leases are recorded on the consolidated balance sheets with right-of-use assets representing the right to use the underlying asset and lease liabilities representing the obligation to make lease payments. Right-of-use assets (“ROU”) and lease liabilities are recognized at lease commencement primarily based on the present value of lease payments over the lease term, and as necessary, at modification. The operating lease ROU assets also include any initial direct costs, lease payments made prior to lease commencement, and lease incentives received. Variable lease payments are expensed as incurred and are not included within the ROU asset and lease liability calculation. Variable lease payments primarily include reimbursements of costs incurred by lessors for common area maintenance and utilities. The Company’s lease terms are the non-cancelable period including any rent-free periods provided by the lessor and may include options to extend or terminate the lease when it is reasonably certain that it will exercise that option. At lease inception, and in subsequent periods as necessary, the Company estimates the lease term based on its assessment of extension and termination options that are reasonably certain to be exercised. Lease costs for lease payments are recognized on a straight-line basis over the lease term. As the rate implicit on the Company’s leases is not readily determinable, the Company uses its secured incremental borrowing rate to determine the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would have to pay to borrow an amount equal to the lease payments on a collateralized basis over a similar term and in a similar economic environment. As of December 31, 2021 and 2022, the Company did not have any material finance leases.

The Company has elected not to separate lease and non-lease components for any leases within its existing classes of assets and, as a result, accounts for any lease and non-lease components as a single lease component. The Company has immaterial leases with a term of 12 months or less.

Revenue Recognition

Revenue RecognitionThe Company’s revenue consists of two components: revenue from fees, net and interest income and fair value adjustments, net. The revenue from fees, net line item on the consolidated statements of operations and comprehensive income (loss) is primarily comprised of platform and referral fees, net, which are recognized based on FASB ASU 2014-09 Topic 606, Revenue from Contracts with Customers.

Operating Expenses

Sales and marketing

Sales and marketing expenses primarily consist of costs incurred across various advertising channels, including expenses for partnerships with third-parties providing borrower referrals, direct mail and digital advertising campaigns, as well as other expenses associated with building overall brand awareness and experiential marketing costs. Sales and marketing expenses also include payroll and other personnel-related costs, including stock-based compensation expense, for related teams. These costs are recognized in the period incurred.

Customer operations

Customer operations expenses include payroll and other personnel-related expenses, including stock-based compensation expense, for personnel engaged in onboarding, loan servicing, customer support and other related operational teams. These costs also include costs of third-party collection agencies and other systems and tools the Company uses as part of information verification, fraud detection, and payment processing activities. These costs are recognized in the period incurred.

Engineering and product development

Engineering and product development expenses primarily consist of payroll and other employee-related expenses, including stock-based compensation expenses, for the engineering and product development teams as well as the costs of systems and tools used by these teams. These costs are recognized in the period incurred.

General, administrative, and other

General, administrative, and other expenses consist primarily of payroll and other employee-related expenses, including stock-based compensation expense for legal and compliance, finance and accounting, human resources and facilities teams, as well as depreciation and amortization of property, equipment and software, professional services fees, facilities and travel expenses. These costs are recognized in the period incurred.

Stock-Based Compensation

The Company issues stock options, restricted stock units (“RSUs”), performance-based restricted stock units (“PRSUs”), and restricted stock to employees and non-employees, including directors and third-party service providers, and employee stock purchase rights granted under the Company’s employee stock purchase plan (“ESPP”). Stock options and employee stock purchase rights granted under the ESPP are initially measured at fair value at the date of grant using the Black-Scholes option-pricing model. RSUs and restricted stock are measured at the fair market value of our common stock at the grant date. PRSUs are initially measured at fair value using a Monte Carlo simulation model. Stock-based compensation expenses are recognized based on their respective grant-date fair values. Forfeitures are estimated at the time of grant and revised, as necessary, in subsequent periods if

actual forfeitures differ from initial estimates. Stock-based compensation expense is recorded net of estimated forfeitures, such that the expense is recorded only for those awards that are expected to vest.

Business Combinations

The Company accounts for business combinations using the acquisition method of accounting which requires the fair values of assets acquired and liabilities assumed to be recognized in the consolidated financial statements. Assets acquired and liabilities assumed in a business combination are recognized at their estimated fair value as of the acquisition date. The excess purchase price over the fair value of assets acquired and liabilities assumed is recorded as goodwill. The allocation of fair values may be subject to adjustment after the initial allocation for up to a one-year period, with the corresponding offset to goodwill. Acquisition-related costs, such as legal and consulting fees, are recognized separately from the business combination and are expensed as incurred.

Non-marketable Equity Security

Non-marketable Equity Securities

The Company’s strategic investments consists of non-marketable equity securities on the consolidated balance sheets which are investments in privately held companies. Non-marketable equity securities do not have a readily determinable fair value and are measured by the Company at cost less impairment, if any, and adjusted for changes resulting from observable price changes in orderly transactions for an identical or similar investment in the same issuer (the “measurement alternative”). Gains and losses on the investment, realized and unrealized, are recognized in other income (expense), net on our consolidated statements of operations and comprehensive income (loss) and a new carrying value is established for the investment upon such recognition of the gains and losses. There have been no unrealized or realized gains and losses or impairments related to the non-marketable equity securities accounted for under the measurement alternative for the years presented. As of December 31, 2021 and 2022, the carrying value of our non-marketable equity securities was $40.0 million and $41.3 million respectively.

The determination of whether an orderly transaction is for an identical or similar investment requires significant management judgment. In its evaluation, the Company considers factors such as differences in the rights and preferences of the investment and the extent to which those differences would affect the fair value of the investment. In the event the Company identifies an observable price change from an orderly transaction for an identical or similar investment of the same issuer, the Company must estimate the fair value of its strategic investments using the most recent data available. The Company’s impairment analysis encompasses an assessment of both qualitative and quantitative factors.

Goodwill and Intangible Assets

Goodwill represents the excess of the purchase price over the fair value of identifiable net assets acquired. Goodwill is reviewed for impairment annually, or more frequently if an event or a change in circumstances indicates that goodwill may be impaired. We first assess qualitative factors to determine if it is more likely than not that the fair value of the reporting unit is less than its carrying value. Examples of qualitative factors include, but are not limited to, a significant adverse change in legal factors or in the business climate, a significant decline in our stock price, a significant decline in our projected revenue or cash flows, or the presence of other indicators that would indicate a reduction in the fair value of a reporting unit. If the Company concludes that it is more likely than not that the fair value of the reporting unit is less than its carrying value, a quantitative test is performed. We perform a quantitative goodwill impairment test by determining the fair value of the reporting unit and comparing it to the carrying value of the reporting unit. If the fair value of the reporting unit is greater than the reporting unit’s carrying value, then the carrying value of the reporting unit is deemed to be recoverable. If the carrying value of the reporting unit is greater than the reporting unit’s fair value, goodwill is impaired and written down to the reporting unit’s fair value.

Acquired intangible assets are recorded at fair value on the date of acquisition and amortized on a straight-line basis over their estimated useful lives. Acquired intangible assets are presented net of accumulated amortization on the consolidated balance sheets. The Company reviews the carrying amounts of intangible assets for impairment

whenever an event or change in circumstances indicates that the carrying amount of the assets may not be recoverable. We measure the recoverability of intangible assets by comparing the carrying amount of each asset to the future undiscounted cash flows we expect the asset to generate. Impairment is measured by the amount in which the carrying value of the asset exceeds its fair value. In addition, we periodically evaluate the estimated remaining useful lives of long-lived intangible assets to determine whether events or changes in circumstances warrant a revision to the remaining period of amortization.

Income Taxes

Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the consolidated financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled.

The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. A valuation allowance may be established to reduce the deferred tax asset to the level at which it is “more likely than not” that the tax asset or benefits will be realized. Realization of tax benefits of deductible temporary differences and operating loss carryforwards depends on having sufficient taxable income of an appropriate character within the carry back or carryforward periods.

The Company recognizes the effect of income tax positions only if those positions are more likely than not of being sustained upon review by the taxing authority. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs.

Other Income (Expense), Net

In April 2020, the Company received a forgivable loan under the Paycheck Protection Program (“PPP”), totaling $5.3 million with a stated annual interest rate of 1%. All loan payments are deferred for six months if not forgiven under the provisions of the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”). The loan and accrued interest are forgivable for borrowers who use the loan proceeds for eligible expenses during a twenty-four week period following the borrower’s receipt of the loan and maintain payroll and employee headcount. The Company has used the full proceeds of the loan for eligible expenses within the required period. The Company determined that forgiveness of the loan under the CARES Act was reasonably assured and recorded the full amount of proceeds as other income in the consolidated statement of operations and comprehensive income (loss) in 2020. In March 2021, the Company voluntarily repaid proceeds received under the Paycheck Protection Program plus accrued interest totaling $5.3 million. The Company recognized the loan principal repayment as an other expense.

Net Income (Loss) Per Share Attributable to Common Stockholders of Upstart Holdings, Inc. Stockholders

The Company follows the two-class method when computing net income (loss) per common share when shares are issued that meet the definition of participating securities. The two-class method determines net income (loss) per common share for each class of common stock and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common stock and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. The Company’s convertible preferred stock contractually entitles the holders of such shares to participate in dividends but does not contractually require the holders of such shares to participate in the Company’s losses. Accordingly, for the periods

where the Company is in a net loss position, the Company does not allocate any net loss attributable to common stockholders to the convertible preferred stock.

Basic net income (loss) per share attributable to common stockholders is computed by dividing the net income (loss) attributable to common stockholders by the weighted-average number of common shares outstanding for the period.

Diluted net income (loss) per share is the amount of net income (loss) available to each share of common stock outstanding during the reporting period, adjusted to include the effect of potentially dilutive common shares. Potentially dilutive common shares include incremental shares issued for convertible preferred stock, stock options, unvested RSUs, purchase rights committed under the ESPP, convertible debt, warrants to purchase convertible preferred stock and warrants to purchase common stock. The calculation of diluted net income (loss) per share excludes all anti-dilutive common shares. For periods in which the Company reports net losses, basic and diluted net loss per share attributable to Upstart Holdings, Inc.’s common stockholders are the same because potentially dilutive common shares are not assumed to have been issued if their effect is anti-dilutive.

Recently adopted and issued accounting pronouncements

Recently Adopted Accounting Pronouncements

The Company did not adopt any new accounting standard during the year ended December 31, 2022:

Recently Issued Accounting Pronouncements

In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting followed by ASU 2021-01, Reference Rate Reform, Scope issued in January 2021 and ASU 2022-06 in December 2022. ASU 2020-04, ASU 2021-01 and ASU 2022-06 provide temporary optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions that reference the London Interbank Offered Rate or another reference rate expected to be discontinued because of reference rate reform, if certain criteria are met. The optional guidance in ASU 2020-04, ASU 2021-01, and ASU 2022-06 is effective for a limited period of time through December 31, 2024 and may be applied prospectively to contract modifications and hedging relationships. The Company does not expect the adoption of this guidance will have a material impact on the Company’s consolidated financial statements or related disclosures.

In October 2021, the FASB issued ASU 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. The new guidance requires contract assets and contract liabilities acquired in a business combination to be recognized and measured by the acquirer on the acquisition date in accordance with ASC 606, Revenue from Contracts with Customers, as if it had originated the contracts. Under the current business combinations guidance, such assets and liabilities are recognized by the acquirer at fair value on the acquisition date. The ASU is effective December 15, 2022, with early adoption permitted. The ASU is to be applied prospectively to business combinations occurring on or after the effective date of the amendment (or if adopted early as of an interim period, as of the beginning of the fiscal year that includes the interim period of early application). This standard has no impact on acquired contract assets or liabilities from business combinations occurring prior to the effective date of adoption. The Company does not expect the adoption of this guidance will have a material impact on the Company’s condensed consolidated financial statements or related disclosures.

Off-Balance Sheet Loans

Off-balance sheet loans relate to securitization transactions for which the Company has some form of continuing involvement, including as servicer. For a loan related to securitization transactions where servicing is the only form of continuing involvement, the Company would only experience a loss if it were required to repurchase such a loan due to a breach in representations and warranties associated with its loan sale or servicing contracts.

The Company routinely contributes loans to securitization transactions which it co-sponsors as a non-retaining sponsor. As a non-retaining sponsor and a servicer of these transactions, the Company does not retain economic risk in these transactions. Contributions of loans to these securitizations are recognized as transfers under ASC 860, Transfers and Servicing