Form 4 Filing for NB Bancorp, Inc. by Mark Whalen

Mark Whalen, a director at NB Bancorp, Inc., reported a disposition of 4,918 shares of Common Stock on April 24, 2026, at a price of $19.82 per share. This transaction resulted in a post-transaction share ownership of 72,721 shares. Additionally, Mr. Whalen holds 30,000 shares indirectly as a trustee for a trust. The filing also notes restricted stock, with 20% vesting annually starting April 24, 2026, and 100% vesting on January 2, 2027.