NB Bancorp, Inc.
NBBK- Exchange
- Nasdaq
- Industry
- Savings Institutions, Not Federally Chartered
- SEC CIK
- 0001979330
In the last 90 days, NB Bancorp, Inc. insiders filed 2 open-market purchases and 1 sale; 161 institutions reported holding it in 13F filings for Q2 2026, worth $474.9M in total; no superinvestor holds it.
Holders of 5% or more of NBBK
Holders whose latest Schedule 13D or 13G filing reports 5% or more of NB Bancorp, Inc., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Needham Bank Employee Stock Ownership Plan Trust | 13G | 7.50%3.42M shares | New | Feb 13, 20261 filing | Feb 13, 2026 | SEC |
| BlackRock, Inc. | 13G/A | 6.70%2.66M shares | – | Oct 17, 20251 filing | Oct 17, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
11 Schedule 13D and 13G filings on NB Bancorp, Inc., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| May 15, 20261:35 PM ET | Pertento Partners LLPand 2 others | 13G/A | 4.60%2.05M shares | −0.50 ppfrom 5.10%Below 5% | Mar 31, 2026 | SEC |
| Mar 27, 202610:48 AM ET | Vanguard Group Inc | 13G/A | 0.00%0 shares | −5.02 ppfrom 5.02%Below 5% | Mar 13, 2026 | SEC |
| Feb 13, 20264:49 PM ET | Needham Bank Employee Stock Ownership Plan Trust | 13G | 7.50%3.42M shares | New | Dec 31, 2025 | SEC |
| Jan 30, 20262:18 PM ET | Vanguard Group Inc | 13G | 5.02%2.30M shares | +0.14 ppfrom 4.88% | Dec 31, 2025 | SEC |
| Dec 5, 20251:00 PM ET | Pertento Partners LLPand 2 others | 13G/A | 5.10%2.34M shares | −0.10 ppfrom 5.20% | Dec 1, 2025 | SEC |
| Oct 17, 20256:24 PM ET | BlackRock, Inc. | 13G/A | 6.70%2.66M shares | – | Sep 30, 2025 | SEC |
| Jul 29, 20252:13 PM ET | Vanguard Group Inc | 13G/A | 4.88%1.98M shares | −0.15 ppfrom 5.03%Below 5% | Jun 30, 2025 | SEC |
| Jun 11, 20255:17 PM ET | Pertento Partners LLPand 1 other | 13G | 5.20%2.11M shares | +0.60 ppfrom 4.60% | Jun 6, 2025 | SEC |
| Apr 30, 202511:23 AM ET | Vanguard Group Inc | 13G | 5.03%2.11M shares | +0.15 ppfrom 4.88% | Mar 31, 2025 | SEC |
| Feb 12, 20257:36 PM ET | Pertento Partners LLPand 1 other | 13G/A | 4.60%1.98M shares | –Below 5% | Dec 31, 2024 | SEC |
| Jan 30, 20259:58 PM ET | Vanguard Group Inc | 13G/A | 4.88%2.09M shares | –Below 5% | Dec 31, 2024 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell NB Bancorp, Inc. shares.
No Form 144 notices for NB Bancorp, Inc. are on file.