v3.25.2
Cover - shares
 6 Months Ended
Jun. 30, 2025
Jul. 29, 2025
Cover [Abstract]    
Document Type 10-Q/A  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 001-39797  
Entity Registrant Name Upstart Holdings, Inc.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 46-4332431  
Entity Address, Address Line One 2950 S. Delaware Street  
Entity Address, Address Line Two Suite 410  
Entity Address, City or Town San Mateo  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94403  
City Area Code 833  
Local Phone Number 212-2461  
Title of 12(b) Security Common Stock, par value $0.0001 per share  
Trading Symbol UPST  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   96,217,742
Amendment Flag true  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001647639  
Fiscal Year End Date --12-31  
Amendment Description Explanatory NoteThis Amendment No. 1 on Form 10-Q/A (“Amendment”) amends the Quarterly Report on Form 10-Q for Upstart Holdings, Inc. (“Company”) for the period ended June 30, 2025 filed with the Securities and Exchange Commission on August 5, 2025 (the “Original Filing”) to revise Part I, Item 2, Management’s Discussion and Analysis of Financial Condition and Results of Operations, subsections “Key operating and Non-GAAP Financial Metrics” and “Reconciliation of Non-GAAP Financial Measures” to correct the Company's diluted Adjusted Net Income (Loss) Per Share for the three and six months ended June 30, 2025. The Company previously reported diluted Adjusted Net Income (Loss) Per Share of $0.36 and $0.62 as of the three and six months ended June 30, 2025, respectively. The corrected diluted Adjusted Net Income (Loss) Per Share is $0.40 and $0.70 as of the three and six months ended June 30, 2025, respectively. This correction has no impact on the Company's net income (loss) per share or any other parts of the Original Filing.This Amendment does not reflect events occurring after the filing of the Original Filing or modify or update those disclosures affected by subsequent events. Except for the items described above or contained in this Amendment, this Amendment speaks as of the original filing date of the Original Filing, and does not modify, amend or update any other item or disclosures in the Original Filing.