NB Bancorp, Inc. — Director's Dealing 2025

Nov 25, 2025

SEC Form 3 — Initial Statement of Beneficial Ownership

Issuer: NB Bancorp, Inc. (NBBK)
CIK: 0001979330
Period of Report: 2025-11-15

Reporting Person: Reilly Joseph B (Director)

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	12012	Direct
Common Stock	36465	Indirect
Common Stock	2398	Indirect

Footnotes

F1: Pursuant to the terms of the Agreement and Plan of Merger, dated June 5, 2025, among NB Bancorp, Inc. ("Needham"), Needham Bank, 1828 MS, Inc., Provident Bancorp, Inc., ("Provident") and BankProv (the "Merger Agreement"), upon the merger of Provident into Needham, effective November 15, 2025 (the "Merger"), each share of Provident common stock was converted into the right to receive, at the election of the holder, either (i) $13.00 in cash or (ii) 0.691 shares of Needham common stock (the "Exchange Ratio"), subject to certain proration and allocation provisions contained in the Merger Agreement.

F2: Pursuant to the terms of the Merger Agreement, each share of Provident common stock was converted into the right to receive, at the election of the holder, (i) $13.00 in cash, or (ii) the Exchange Ratio, subject to certain proration and allocation provisions contained in the Merger Agreement.