PRE-EFFECTIVE AMENDMENT NO. 4 TO THE FORM S-1 REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933 NB Bancorp, Inc. Needham Bank 401(k) Plan (Exact Name of Registrant as Specified in Its Charter) (State or Other Jurisdiction of (Primary Standard Industrial (I.R.S. Employer Incorporation or Organization) Classification Code Number) Identification Number) As filed with the Securities and Exchange Commission on September 29, 2023 Registration No. 333-272567 UNITED STATES SECURITIES AND EXCHANGE COMMISSION W ...