Joseph P. Campanelli - 09 Jun 2025 Form 4 Insider Report for NB Bancorp, Inc. (NBBK)

Role: President & CEO, Director, Chairman of the Board
Signature: /s/ Steven Lanter, pursuant to power of attorney
Issuer symbol: NBBK
Transactions as of: 09 Jun 2025
Net transactions value: +$113,828
Form type: 4
Filing time: 10 Jun 2025, 15:25:01 UTC
Previous filing: 28 Apr 2025
Next filing: 27 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
CAMPANELLI JOSEPH P	President & CEO, Director, Chairman of the Board	1063 GREAT PLAIN AVE, NEEDHAM	/s/ Steven Lanter, pursuant to power of attorney	10 Jun 2025	0001222378

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	NBBK	Common Stock	Purchase	$16,030	+1,000	+0.3%	$16.03	330,146	09 Jun 2025	Direct	F1
transaction	NBBK	Common Stock	Purchase	$1,633	+100	+0.03%	$16.33	330,246	09 Jun 2025	Direct	F1
transaction	NBBK	Common Stock	Purchase	$14,715	+900	+0.27%	$16.35	331,146	09 Jun 2025	Direct	F1
transaction	NBBK	Common Stock	Purchase	$81,450	+5,000	+12%	$16.29	45,000	09 Jun 2025	By IRA
holding	NBBK	Common Stock						1,877	09 Jun 2025	By ESOP
holding	NBBK	Common Stock						47,788	09 Jun 2025	By 401(k)	F2

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

Explanation of Responses:

Id	Content
F1	Includes shares of restricted stock which vest at a rate of 20% per year commencing on April 24, 2026.
F2	Reflects transactions not required to be reported pursuant to Section 16 of the Securities Act of 1934, as amended.