NB Bancorp Inc美股招股说明书(2025-07-30版)

PROXY STATEMENT/PROSPECTUS Dear Provident Stockholders: On behalf of Provident Bancorp, Inc. (“Provident”), we are pleased to enclose the accompanying proxystatement/prospectus relating to the acquisition of Provident by NB Bancorp, Inc. (“Needham”). We arerequesting that you take certain actions as a Provident stockholder. On June5, 2025, Needham, Needham Bank, a wholly-owned subsidiary of Needham, 1828 MS, Inc., awholly-owned subsidiary of Needham (the “Merger Sub”), Provident, and BankProv, a wholly-ownedsubsidiary of Provident, entered into an Agreement and Plan of Merger (the “merger agreement”), pursuantto which Needham will, upon the terms and subject to the conditions set forth in the merger agreement,acquire Provident and BankProv through the merger of Merger Sub with and into Provident (the “merger”)followed as soon as reasonably practicable by the merger of Provident with and into Needham (the “HoldcoMerger”), with Needham as the surviving entity. The merger agreement further provides that after theHoldco Merger, at a time selected by Needham, BankProv will merge with and into Needham Bank, withNeedham Bank as the surviving entity (the “Bank Merger” and, together with the merger and the HoldcoMerger, the “Transaction”). If the merger is completed, Provident stockholders will receive, for each share of Provident commonstock, par value $0.01 per share (“Provident common stock”), at the holder’s election, either (i)0.691 sharesof Needham common stock (the “stock consideration” or the “exchange ratio”) or (ii)$13.00 in cash (the“cash consideration”), subject to allocation procedures to ensure that the total number of shares of Providentcommon stock that receive the stock consideration represents 50% of the total number of shares ofProvident common stock outstanding immediately prior to the completion of the merger. Providentstockholders will also receive cash in lieu of any fractional shares of Needham common stock, par value$0.01 per share (“Needham common stock”), they would have otherwise received in the merger. The precisevalue of the consideration that Provident stockholders will receive will not be known at the time thatProvident stockholders vote on the Merger Proposal (as defined below). On June5, 2025, which was the lasttrading day preceding the public announcement of the proposed merger, the closing price of Needhamcommon stock was $16.65 per share, which after giving effect to the exchange ratio for a Providentstockholder who receives stock consideration has an implied value of $11.51 per share of Providentcommon stock. OnJuly29, 2025, which was the most recent practicable trading day before the printing ofthis proxy statement/prospectus, the closing price of Needham common stock was $17.99 per share, which,after giving effect to the exchange ratio for a Provident stockholder who receives stock consideration, hasan implied value of approximately $12.43 per share of Provident common stock. The value of the Needham common stock at the time of completion of the merger could be greater than,less than or the same as the value of Needham common stock on the date of the accompanying proxystatement/prospectus.We urge you to obtain current market quotations of Needham common stock (tradingsymbol “NBBK”) and Provident common stock (trading symbol “PVBC”), both of which are traded on theNasdaq Stock Market, LLC. Based on the number of shares of Provident common stock outstanding or reserved for issuance as ofthe record date of July 21, 2025, Needham expects to issue approximately 5.9 million shares of Needhamcommon stock to Provident stockholders in the aggregate in the merger. We estimate that, immediatelyfollowing the completion of the merger, former Provident stockholders will own approximately 14.54% ofthe common stock of Needham. Provident will hold, by means of remote communication athttps://www.cstproxy.com/bankprov/sm2025, a special meeting of Provident stockholders (the “specialmeeting”) on September 16, 2025 at 10:00 a.m., Eastern Time, where Provident stockholders will be askedto vote on a proposal to approve the merger agreement and the merger (the “Merger Proposal”), and aproposal to approve, on a non-binding advisory basis, the compensation that may become payable to thenamed executive officers of Provident in connection with the merger (the “Merger-Related CompensationProposal”). Information about the special meeting and the merger is contained in this document. We urgeyou to read this document carefully and in its entirety. The Provident board of directors unanimously recommends that Provident stockholders vote “FOR” eachof the proposals to be considered at the special meeting. This proxy statement/prospectus provides you with detailed information about the merger agreementand the merger. It also contains or references information about Needham and Provident and certain relatedmatters. You are encouraged to read this proxy statement/prospectus carefully.In particular, you sho