BCB Bancorp, Inc.

Item 1.01. Entry Into a Material Definitive Agreement On September 16, 2026, BCB Bancorp, Inc. (the “Company”) and its wholly owned subsidiary, BCB Community Bank (the “Bank”), entered into an Underwriting Agreement (the “Underwriting Agreement”) with Piper Sandler & Co. (the “Underwriter”) under which the Company agreed to sell up to 12,650,000 shares of its common stock, inclusive of a customary over-allotment option, to the Underwriter. The Underwriting Agreement contains customary representations, warranties and agreements of the Company, conditions to closing, indemnification rights and obligations of the parties, and termination provisions. Under the terms of the Underwriting Agreement, the Company and the Bank agreed to indemnify the Underwriter against certain specified types of liabilities, including liabilities under the Securities Act of 1933, as amended, and to contribute to payments the Underwriter may be required to make in respect of these liabilities.

Item 8.01. Other Events On September 18, 2026, the Company issued 11,000,000 shares of its common stock, without par value, (the “Underwritten Shares”). The net proceeds of the offering of the Underwritten Shares were approximately $79,561,000 after deducting underwriting discounts and commissions and estimated offering expenses. The Underwriter exercised its overallotment option to purchase 1,650,000 additional shares of common stock in full. Therefore, the Company issued and sold an additional 1,650,000 shares of common stock (together with the Underwritten Shares, the “Shares”), and the aggregate net proceeds of the offering of the Shares, after deducting underwriting discounts and commissions and estimated offering expenses, were approximately $92,445,438. The Company issued a press release announcing the closing of the offering. The offering was made pursuant to a prospectus supplement dated September 16, 2026 and the accompanying prospectus dated August 25, 2026, filed with the Securities and Exchange Commission pursuant to the Company’s Registration Statement on Form S-3 (File No. 333-298337). Copies of a validity opinion with respect to the Shares, the Underwriting Agreement, and the Company’s press release are attached as Exhibits 5.1, 10.1 and 99.1, respectively, to this Current Report on Form 8-K and are incorporated by reference into the Registration Statement.