[Form 4] Brookline Bancorp Inc Insider Trading Activity

Rhea-AI Filing Summary

Brookline Bancorp (BRKL) – Form 4 insider filing. General Counsel Marissa S. Martin reported Code F transactions on 2 Aug 2025, indicating shares were withheld by the issuer to satisfy tax obligations arising from previously granted performance-based restricted stock.

• Securities withheld: 3,674 common shares across four entries at an indicated price of $10.28.
• Post-transaction ownership: 40,676 direct shares and 821 shares held indirectly through the ESOP, totalling 41,497.
• Equity source: Shares originate from the 2021 Stock Option & Incentive Plan; remaining restricted shares vest on the third anniversary of grant subject to performance metrics.

No derivative transactions were reported. The filing does not reflect open-market buying/selling and appears routine for tax-withholding purposes. Impact on float and insider sentiment is immaterial due to the small volume relative to BRKL’s outstanding shares.

Positive

• No discretionary insider selling; shares surrendered solely for tax, limiting bearish signal
• Insider retains significant stake (≈41k shares), suggesting continued alignment with investors

Negative

• Insider share count falls by 3,674, a modest dilution of insider ownership

Insights

Securities Analyst

TL;DR: Routine tax-withholding; negligible market impact.

The Code F classification signals issuer-withheld shares rather than discretionary selling, limiting negative read-through. Only 3,674 shares (≈0.004% of ~83 m shares outstanding) left the insider’s direct holdings. Martin retains >41k shares, maintaining alignment with shareholders. Because no open-market price discovery occurred and no derivative positions changed, I view the event as neutral for valuation and sentiment.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Martin Marissa S.

(Last) (First) (Middle)

131 CLARENDON STREET

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
BROOKLINE BANCORP INC [ BRKL ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	General Counsel

3. Date of Earliest Transaction (Month/Day/Year)
08/02/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common	08/02/2025		F		1,596(1)	D	$10.28	42,754	D
Common	08/02/2025		F		532	D	$10.28	42,222	D
Common	08/02/2025		F		723	D	$10.28	41,499	D
Common	08/02/2025		F		823	D	$10.28	40,676(2)	D
Common								821	I	By ESOP

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Performance based restricted stock shares granted pursuant to the Brookline Bancorp, Inc. 2021 Stock Option and Incentive Plan. The shares vest on the third anniversary of the date of grant based on certain performance based metrics.

2. Includes shares of restricted stock granted pursuant to the Brookline Bancorp, Inc. 2021 Stock Option and Incentive Plan.

Remarks:

	Marissa S. Martin	08/05/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What type of insider transaction is reported for BRKL?

The Form 4 shows a Code F transaction, meaning shares were withheld by Brookline Bancorp to cover tax obligations from restricted-stock vesting.

How many Brookline Bancorp shares were surrendered?

A total of 3,674 common shares were withheld at $10.28 per share for tax purposes.

What is Marissa S. Martin’s shareholding after the transaction?

She now holds 40,676 direct shares and 821 indirect ESOP shares, totalling 41,497.

Were any derivative securities involved?

No derivative securities were acquired or disposed of; Table II is blank.

Does this filing indicate insider selling pressure on BRKL stock?

Likely not; Code F indicates non-discretionary tax withholding, a routine event with minimal market impact.