As filed with the U.S. Securities and Exchange Commission on December 19, 2025. Registration No. 333- UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Legato Merger Corp. IV (Exact name of registrant as specified in its charter) Cayman Islands 6770 98-1880768 (State or other jurisdiction of incorporation or organization) (Primary Standard Industrial Classification Code Number) Legato Merger Corp. IV 777 Third Avenue, 37 ...