Michael James Sullivan - Nov 1, 2025 Form 3 Insider Report for Eastern Bankshares, Inc. (EBC)

Role: Director
Signature: /s/ Kathleen R. Henry, by Power of Attorney
Stock symbol: EBC
Transactions as of: Nov 1, 2025
Transactions value $: $0
Form type: 3
Date filed: 11/10/2025, 04:10 PM
Previous filing: Mar 4, 2025
Next filing: Nov 25, 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Sullivan Michael James	Director	125 HIGH STREET, BOSTON	/s/ Kathleen R. Henry, by Power of Attorney	2025-11-10	0001676055

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	EBC	Common Stock						64.6K	Nov 1, 2025	Direct	F1
holding	EBC	Common Stock						707	Nov 1, 2025	Held by Double Eagle LLC	F2
holding	EBC	Common Stock						711	Nov 1, 2025	Rollover 401(k)	F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	EBC	Stock Option (Right to Buy)							Nov 1, 2025	Common Stock	63.7K	$13.38	Direct	F3, F4, F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Pursuant to the terms of the Agreement and Plan of Merger dated April 24, 2025 among Eastern Bankshares, Inc. ("Eastern"), Eastern Bank, HarborOne Bancorp, Inc. (HarborOne"), and HarborOne Bank (the "Merger Agreement"), upon the merger of HarborOne into Eastern, effective November 1, 2025 (the "Merger"), each share of HarborOne common stock was converted into the right to receive, at the election of the holder, either (i) $12.00 in cash or (ii) 0.765 shares of Eastern common stock (the "Exchange Ratio"), subject to certain proration provisions contained in the Merger Agreement. In addition to the shares of common stock received by the reporting person in the Merger, the total common stock includes 5,000 shares owned by reporting person prior to the Merger.
F2	Pursuant to the terms of the Merger Agreement, each share of HarborOne common stock was converted into the right to receive, at the election of the holder, either (i) $12.00 in cash or (ii) the Exchange Ratio, subject to certain proration provisions contained in the Merger Agreement.
F3	Pursuant to the terms of the Merger Agreement, the stock option must be exercised no later than May 1, 2026 (i.e., within six (6) months from the time reporting person's employment as a director of HarborOne was terminated).
F4	Pursuant to the Merger Agreement, each outstanding and unexercised option to purchase shares of HarborOne common stock was converted into an option to purchase shares of Eastern common stock by multiplying the number of shares by the Exchange Ratio (rounded down to the nearest whole share).
F5	Pursuant to the Merger Agreement, the exercise price per share of each converted option was determined by dividing the exercise price of the HarborOne stock option by the Exchange Ratio (rounded up to the nearest whole cent).