# EDGAR Filing Document

**Accession Number:** 0002058758
**File Stem:** 0000943374-25-000352
**Filing Date:** 2025-7
**Character Count:** 8752
**Document Hash:** b57fb67a8902b4f17ebde05e9d561468
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000943374-25-000352.hdr.sgml**: 20250731

**ACCESSION NUMBER**: 0000943374-25-000352

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20250731

**ITEM INFORMATION**: Other Events

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20250731

**DATE AS OF CHANGE**: 20250731

**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:** 000000000
- **STATE OF INCORPORATION:** MD
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42775
- **FILM NUMBER:** 251172769

**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): July 31, 2025

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

---

| | | | |
|:---|:---|:---|:---|
| 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 8.01 Other Events.**

On July 31, 2025, Avidia Bancorp, Inc., the stock holding company of Avidia Bank, closed its initial public offering in connection with the mutual-to-stock conversion of Assabet Valley Bancorp, the former mutual holding company of Avidia Bank. For further information, reference is made to the press release filed as an exhibit hereto and incorporated herein by reference.

**Item 9.01 Financial Statements and Exhibits.**

&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 July 31, 2025

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

------

#### 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.

---

| | |
|:---|:---|
|  | **Avidia Bancorp, Inc.** |
| Date: July 31, 2025 | &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; By: <u>/s/ Jonathan Nelson</u><br> Jonathan Nelson<br> Chief Financial Officer |

---

## Exhibit 99.1

Exhibit 99.1<br>

<u>PRESS RELEASE</u>

<u>Contact</u>:

Robert D. Cozzone

President and Chief Executive Officer

Avidia Bancorp, Inc.

(800) 508-2265

#### Avidia Bancorp, Inc. Closes Initial Public Offering

Hudson, MA; July 31, 2025 – Avidia Bancorp, Inc. (the "Company"), the stock holding company of Avidia Bank, announced today the closing of its initial public offering in connection with the mutual-to-stock conversion of Assabet Valley Bancorp, the former mutual holding company of Avidia Bank, effective as of the close of business today. Listing of the Company's common stock on the New York Stock Exchange under the ticker symbol "AVBC" is expected to begin on August 1, 2025.

The Company sold 19,176,250 shares of common stock (the adjusted maximum of the offering range), which includes 1,606,100 shares sold to Avidia Bank's Employee Stock Ownership Plan (the "ESOP"), at a price of $10.00 per share for gross offering proceeds (before deducting offering expenses) of approximately $191.8 million. The Company also contributed 900,000 additional shares of its common stock to the Avidia Bank Charitable Foundation, Inc., established and funded in connection with the conversion. The Company has 20,076,250 shares of common stock issued and outstanding as a result of the closing of the conversion and stock offering.

As previously disclosed, the Company's subscription offering was oversubscribed in the first-tier by eligible depositors of Avidia Bank as of the close of business on December 31, 2023. All valid subscription orders submitted by first-tier eligible depositors of Avidia Bank and by the ESOP were filled according to the priorities and allocation procedures disclosed in the Company's Prospectus dated May 13, 2025. All other subscribers who submitted valid subscription orders will have their subscription funds refunded in full, with interest, as disclosed in the Prospectus.

Purchasers wishing to confirm their stock purchases may do so by contacting the Stock Information Center at (877) 821-5783 (toll-free). The Stock Information Center is open Monday through Friday 10:00 a.m. to 4:00 p.m., Eastern time, except bank holidays. Purchasers may also confirm their stock purchases online at *https://allocations.kbw.com*.

Continental Stock Transfer & Trust Company, the Company's transfer agent, plans to mail Direct Registration System ("DRS") Book-Entry statements for the shares of common stock purchased in the subscription offering, as well as refund and interest checks, on or about July 31, 2025.

Luse Gorman, PC acted as legal counsel to the Company, Assabet Valley Bancorp and Avidia Bank. Keefe, Bruyette & Woods, Inc., a Stifel Company, acted as marketing agent for the Company in the subscription offering, and Nutter McClennen & Fish LLP acted as its legal counsel.

#### 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.

#### Forward-Looking Statements
This press release contains certain forward-looking statements about the conversion and stock offering. Forward-looking statements include statements regarding anticipated future events and can be identified by the fact that they do not relate strictly to historical or current facts. They often include words such as "believe," "expect," "anticipate," "estimate," and "intend" or future or conditional verbs such as "will," "would," "should," "could," or "may." Forward-looking statements, by their nature, are subject to risks and uncertainties. Certain factors that could cause actual results to differ materially from expected results include possible unforeseen delays in delivering DRS Book-Entry statements and/or refund and interest checks and/or unforeseen delays in the start of stock trading due to market disruptions or otherwise.

#### Legal Disclosure
**The shares of common stock of Avidia Bancorp, Inc. are not deposit accounts or savings accounts and are not insured by the Federal Deposit Insurance Corporation, the Depositors Insurance Fund or any other government agency.**

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