SCHEDULE 13G 0002044671 XXXXXXXX LIVE Class A common stock, par value $0.01 per share 12/31/2025 0001392272 CHAIN BRIDGE BANCORP INC 15746L100 1445-A LAUGHLIN AVENUE MCLEAN VA 22101 Rule 13d-1(b) Hingham Institution for Savings MA 293565.00 0.00 293565.00 0.00 293565.00 8.9 BK CHAIN BRIDGE BANCORP INC 1445-A LAUGHLIN AVENUE, MCLEAN, VIRGINIA, 22101. This Schedule 13G is being jointly filed by Hingham Institution for Savings and its fully owned subsidiary Hingham Unpledged Securities Corporation. 55 Main Street, Hingham, MA 02043 Hingham Institution for Savings and its fully owned subsidiary Hingham Unpledged Securities Corporation are organized under the laws of the Commonwealth of Massachusetts. N BK 293,565 8.9 293,565 0 293,565 0 Y N Y N Hingham Institution for Saving acquired the security via its fully owned subsidiary, the Hingham Unpledged Securities Corporation. This Corporation is organized under the laws of the Commonwealth of Massachusetts. Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Hingham Institution for Savings Cristian Melej 01/30/2026