# EDGAR Filing Document

**Accession Number:** 0002058758
**File Stem:** 0000943374-25-000418
**Filing Date:** 2025-9
**Character Count:** 7925
**Document Hash:** 93ee8763e836eace40f37db7f18e7689
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000943374-25-000418.hdr.sgml**: 20250925

**ACCESSION NUMBER**: 0000943374-25-000418

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 14

**CONFORMED PERIOD OF REPORT**: 20250925

**ITEM INFORMATION**: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20250925

**DATE AS OF CHANGE**: 20250925

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Avidia Bancorp, Inc.
- **CENTRAL INDEX KEY:** 0002058758
- **STANDARD INDUSTRIAL CLASSIFICATION:** SAVINGS INSTITUTIONS, NOT FEDERALLY CHARTERED [6036]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 334239888
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42775
- **FILM NUMBER:** 251344540

**BUSINESS ADDRESS:**
- **STREET 1:** 42 MAIN STREET
- **CITY:** HUDSON
- **STATE:** MA
- **ZIP:** 01749
- **BUSINESS PHONE:** 800-508-2265

**MAIL ADDRESS:**
- **STREET 1:** 42 MAIN STREET
- **CITY:** HUDSON
- **STATE:** MA
- **ZIP:** 01749

?xml version='1.0' encoding='ASCII'?

#### UNITED STATES

#### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

#### FORM 8-K

#### CURRENT REPORT

#### Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): September 25, 2025

#### Avidia Bancorp, Inc.
(Exact Name of Registrant as Specified in its Charter)

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| | | | |
|:---|:---|:---|:---|
| Maryland<br>| 001-42775<br>| 33-4239888 | 33-4239888 |
| (State or Other Jurisdiction of Incorporation) | (Commission File No.) | (I.R.S. Employer Identification No.) | (I.R.S. Employer Identification No.) |
| 42 Main Street, Hudson, Massachusetts | 42 Main Street, Hudson, Massachusetts | | 01749<br>|
| (Address of Principal Executive Offices) | (Address of Principal Executive Offices) | | (Zip Code) |

---

<u>(800) 508-2265</u>

(Registrant's telephone number, including area code)

<u>Not Applicable</u>

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| Common stock, $0.01 par value per share<br>| AVBC<br>| The New York Stock Exchange<br>|
| Title of Each Class | Trading Symbol(s) | Name of Each Exchange on Which Registered |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 or Rule 12b-2 of the Securities Exchange Act of 1934.

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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| | |
|:---|:---|
| **Item 5.02.** | **Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.** |

---

On September 25, 2025, Avidia Bancorp, Inc. (the "Company") appointed Michael O. Gilles to its Board of Directors, to serve in the class of Directors with terms expiring in 2028. Avidia Bank, the Company's bank subsidiary, also appointed Mr. Gilles to serve on its Board of Directors. For further information, reference is made to the press release dated September 25, 2025, a copy of which is attached as an exhibit hereto and incorporated herein by reference.

There is no arrangement or understanding between Mr. Gilles and any other person pursuant to which he was selected as a Director.

Mr. Gilles has been appointed to serve on the Audit Committee of the Company's Board of Directors.

There are no transaction since the beginning of the Company's last fiscal year, or any currently proposed transactions, in which the Company was or is to be a participant and the amount involved exceeds $120,000, and in which Mr. Gilles had or will have a direct or indirect material interest.

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| | |
|:---|:---|
| **Item 9.01**  | **Financial Statements and Exhibits.**<br>|

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(d) Exhibits

Exhibit No. Description

[99.1](ex99-1.htm) Press Release dated September 25, 2025

104 Cover Page Interactive Data File (Embedded within Inline XBRL document)

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#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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| | | |
|:---|:---|:---|
|  |  | **Avidia Bancorp, Inc.** |
| Date: September 25, 2025  | By: <br>| /s/ Robert D. Cozzone |
|  |  | Robert D. Cozzone |
|  |  | President and Chief Executive Officer |

---

## Exhibit 99.1

Exhibit 99.1<br>

![](image00001.jpg)

#### AVIDIA BANCORP, INC. APPOINTS MICHAEL GILLES TO BOARD OF DIRECTORS
Hudson, MA; September 25, 2025 – Avidia Bancorp, Inc. (NYSE: AVBC), parent of Avidia Bank, today announced the appointment of Michael "Mike" Gilles to its Board of Directors and to the Board of Directors of Avidia Bank, effective September 25, 2025.

"We are thrilled to have Mike join our Board as we transition to a public company. His financial expertise and decades of local community banking experience will be invaluable to Avidia," said Michael Murphy, Chairman of the Board.

"I am delighted to join the Avidia Board of Directors, and to have the opportunity to work with an exceptional group of professionals," said Michael Gilles. "I look forward to leveraging my insights and experience to help the bank as it builds toward the future."

Mr. Gilles is a seasoned financial services executive who brings over 45 years of community banking experience to Avidia. Prior to starting a bank consultancy practice in 2024, he served as the Executive Vice President, Chief Operating and Financial Officer of Cambridge Financial Group, Inc., the holding company for Cambridge Savings Bank in Cambridge, MA. His professional background includes executive positions at several Massachusetts mutual and public banks. He possesses extensive knowledge of all areas of banking and has specific expertise in financial management and reporting, internal controls, asset/liability and investment portfolio management, mergers and acquisitions, credit administration and risk management. Mr. Gilles is a native of Hudson, MA, where Avidia Bank is headquartered.

Mr. Gilles is a Certified Management Accountant and earned a bachelor's degree in accountancy from Bentley University. He is also a graduate of the Stonier Graduate School of Banking.

In addition to his consulting work Mr. Gilles is the Treasurer and a director of the Bay State Federal Savings Charitable Foundation. He has served in advisory roles at the Massachusetts Bankers Association and the Federal Home Loan Bank of Boston and is a past President of the Financial Managers Society, Boston Chapter.

#### About Avidia Bank
Avidia Bank is a Massachusetts-chartered stock savings bank. With headquarters in Hudson, Massachusetts, it also operates nine full-service banking offices in western Middlesex County and eastern Worcester County in Massachusetts.

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