Form S-1 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Amendment No. 1 to As filed with the Securities and Exchange Commission on November 17, 2025. Registration Statement No. 333-291106 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 Direct Digital Holdings, Inc. (Exact name of registrant as specified in its charter) (State or Other Jurisdiction of Incorporation or Organization) (Primary Standard Industrial Classification Code Number) Delaware 7370 87-2306185 (I.R.S. Emplo ...