Rubico Inc美股招股说明书(2026-04-07版)

Up to 15,000,000 Common Shares RUBICO INC. This is a supplement (the “Prospectus Supplement”) to the prospectus, dated September 19, 2025 (as supplemented oramended from time to time, the “Prospectus”) of Rubico Inc. (the “Company”), which forms a part of the Company’s RegistrationStatement on Form F-1 (Registration Nos. 333-288796, 333-291884 and 333-293441), as amended from time to time. This Prospectus Supplement is being filed to update and supplement the information included in the Prospectus with theinformation contained in the Company’s Report on Form 6-K, furnished to the U.S. Securities and Exchange Commission (the“Commission”) on April 7, 2026 (the “Form 6-K”). Accordingly, the Form 6-K is attached to this Prospectus Supplement. This Prospectus Supplement should be read in conjunction with, and delivered with, the Prospectus and is qualified byreference to the Prospectus except to the extent that the information in this Prospectus Supplement supersedes the informationcontained in the Prospectus. This Prospectus Supplement is not complete without, and may not be delivered or utilized except in connection with, theProspectus, including any amendments or supplements to it. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 12 of the Prospectusfor a discussion of information that should be considered in connection with an investment in our securities. Neither the Commission nor any state securities commission has approved or disapproved of these securities ordetermined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense. The date of this prospectus supplement is April 7, 2026. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE SECURITIESEXCHANGE ACT OF 1934 For the month of April 2026 Commission File Number:001-42684 Rubico Inc.(Translation of registrant's name into English) 20 Iouliou Kaisara Str19002 PaianiaAthens, Greece(Address of principal executive office) Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.Form 20-F [X ]Form 40-F [] On April 7, 2026, the Registrant issued a press release, a copy of which is attached hereto as Exhibit 99.1 and is incorporated herein byreference. Attached hereto as Exhibit 1.1 is a copy of the Articles of Amendment to the Amended and Restated Articles ofIncorporation of the Registrant, filed with the Registrar of Corporations of the Republic of the Marshall Islands on April 7, 2026. Articles of Amendment to Amended and Restated Articles of Incorporation Exhibit 1.1 Exhibit 99.1Press Release dated April 7, 2026 SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on itsbehalf by the undersigned, thereunto duly authorized. Rubico Inc.(Registrant)/s/ Nikolaos PapastratisNikolaos PapastratisChief Financial Officer Date: April 7, 2026 ARTICLES OF AMENDMENTOFRUBICO INC.Reg. No. 115734 NON-RESIDENT Karim FakhriDeputy Registrar ARTICLES OF AMENDMENTTO THEAMENDED AND RESTATED ARTICLES OF INCORPORATIONOFRUBICO INC.PURSUANT TO SECTION 90 OFTHE MARSHALL ISLANDS BUSINESS CORPORATIONS ACT The undersigned, Nikolaos Papastratis, as the Chief Financial Officer of Rubico Inc., a corporation incorporated under thelaws of the Republic of the Marshall Islands (the “Corporation”), for the purpose of amending the Amended and Restated Articles ofIncorporation of said Corporation pursuant to Section 90 of the Business Corporations Act, as amended, hereby certifies that: 1.The name of the Corporation is: Rubico Inc. 2.The Articles of Incorporation were filed with the Registrar of Corporations as of the 11th day of August, 2022, and wereamended and restated in their entirety as of the 26th day of June, 2025. Articles of Amendment were filed with the Registrar of Corporations on the 1st day of December, 2025. Articles of Amendment were filed with the Registrar of Corporations on the 10th day of February, 2026. 3.Section D of the Amended and Restated Articles of Incorporation, as amended, is hereby amended by adding the followingparagraph to the end of the Section: Effective with the commencement of business on April 9, 2026, the Corporation has effected a one-for-ten reverse stocksplit as to its issued and outstanding common shares, pursuant to which the number of issued common shares shalldecrease from approximately 7,573,572 to approximately 757,356 as adjusted for the cancellation of fractional shares andwhich may be further adjusted for the cancellation of fractional shares. The reverse stock split shall not change thenumber of registered common shares the Corporation is authorized to issue or the par value of the common shares. Thestated capital of the Corporation is hereby reduced from approximately $75,735.