SCHEDULE 13G 0002096685 XXXXXXXX LIVE Common Stock, par value $0.01 per share 09/30/2025 0002058758 Avidia Bancorp, Inc. 05369T100 42 Main Street Hudson MA 01749 Rule 13d-1(b) Avidia Bank Employee Stock Ownership Plan Trust b MA 1606100 0 1606100 0 1606100 N 8 EP Avidia Bancorp, Inc. 42 Main Street, Hudson, Massachusetts, 01749 Avidia Bank Employee Stock Ownership Plan Trust, Trustee: Delaware Charter Guarantee & Trust Company dba Principal Trust Company 1013 Centre Road, Suite 300, Wilmington, Delaware 19805 Massachusetts N EP 1,606,100 8.0 1,606,100 0 1,606,100 0 Y Y Y N The reporting person is an employee benefit plan subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended. 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. Avidia Bank Employee Stock Ownership Plan Trust /s/ Jared Gillespie 11/13/2025