As filed with the Securities and Exchange Commission on October 8, 2025. Registration No. 333-290426 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Rubico Inc. (Exact name of Registrant as specified in its charter) Republic of the Marshall Islands (State or other jurisdiction of incorporation or organization) 4412 (Primary Standard Industrial Classification Code Number) N/A (I.R.S. Employer Identification No.) 20 Iouliou Kaisara Str 19002 Paiania Athens, Greece +30 210 812 8107 (Add ...