Joseph P. Campanelli - 20 Aug 2026 Form 4 Insider Report for NB Bancorp, Inc. (NBBK)

Reporting relationship: President & CEO, Director, Chairman of the Board
Issuer ticker: NBBK
Reported as of: 20 Aug 2026
Net transaction value: +$43,500
SEC form: 4
Accepted by SEC: 21 Aug 2026, 16:57:56 UTC
Prior SEC filing: 18 May 2026
Source filing: View source filing
Reporting owner signature: /s/ Kate Henry, by Power of Attorney

Key filing fact

Joseph P. Campanelli filed Form 4 for NB Bancorp, Inc. (NBBK) on 21 Aug 2026.

Key facts

This page summarizes Joseph P. Campanelli's Form 4 filing for NB Bancorp, Inc. (NBBK).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 21 Aug 2026, 16:57.

Change

Previous filing in this sequence was filed on 18 May 2026.
Current net transaction value: +$43,500.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001222378 Primary reporting owner

CAMPANELLI JOSEPH P

Relationship: President & CEO, Director, Chairman of the Board
Address: 1063 GREAT PLAIN AVE, NEEDHAM
Signature: /s/ Kate Henry, by Power of Attorney
Signature date: 21 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

NBBK transaction

Common Stock

Purchase

Transaction value: $43,500
Shares: +2,000
Change %: +0.53%
Price: $21.75
Shares after: 379,790
Date: 20 Aug 2026
Ownership: Direct
Footnotes: F1, F2

NBBK holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 47,000
Date: 20 Aug 2026
Ownership: By IRA

NBBK holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 3,000
Date: 20 Aug 2026
Ownership: As trustee for trust

NBBK holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 51,220
Date: 20 Aug 2026
Ownership: By 401(k)

NBBK holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 3,677
Date: 20 Aug 2026
Ownership: By ESOP

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

Includes shares of restricted stock which vest at a rate of 20% per year commencing on April 24, 2026.

Footnote F2

Shares of restricted stock vest at a rate of 33 1/3% per year commencing on February 25, 2027.

SEC remarks

Exhibit List: Exhibit 24 - Power of Attorney