Oklo Inc.-美国存托股招股说明书（2025年4月22日版）

OKLO INC. This prospectus supplement updates, amends and supplements the prospectus dated September 18, 2024 (the “Prospectus”), whichforms a part of our Registration Statement on Form S-1, as amended (Registration No. 333-280344). Capitalized terms used in thisprospectus supplement and not otherwise defined herein have the meanings specified in the Prospectus. This prospectus supplement is being filed to update, amend and supplement the information included in the Prospectus with theinformation contained in our Current Report on Form 8-K, filed with the Securities and Exchange Commission on April 22, 2025, This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction withthe Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extent that Oklo Inc.’s Class A Common Stock is quoted on the New York Stock Exchange under the symbol “OKLO.” On April 22, 2025, theclosing price of our Class A Common Stock was $21.53. WE ARE AN “EMERGING GROWTH COMPANY” UNDER FEDERAL SECURITIES LAWS AND ARE SUBJECT TOREDUCED PUBLIC REPORTING REQUIREMENTS. INVESTING IN OUR SECURITIES INVOLVES CERTAIN RISKS. SEE Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securitiesor determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal The date of this prospectus supplement is April 22, 2025. FORM8-K ¨Written communications pursuant to Rule425 under the Securities Act (17 CFR 230.425)¨Soliciting material pursuant to Rule14a-12 under the Exchange Act (17 CFR 240.14a-12) Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; CompensatoryArrangements of Certain Officers. On April 22, 2025, Sam Altman notified the board of directors (the “Board”) of Oklo Inc. (the “Company”) that he intended to resignas Chair and as a Class II director of the Board, including as a member of the Board’s Nominating and Corporate GovernanceCommittee, effective April 22, 2025. Mr. Altman’s decision to resign was not due to any disagreement with the Company on any SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed onits behalf by the undersigned hereunto duly authorized. Oklo Inc.By:/s/ R. Craig BealmearName:R. Craig BealmearTitle:Chief Financial Officer Date: April 22, 2025