NB Bancorp, Inc. (NBBK) Ownership
NBBK ownership summary
as of October 18, 2026- Institutions
- 52.6% of shares outstanding
- Insiders
- 12.53% of shares outstanding
- Shares outstanding
- 43.8M
- Float
- 37.1M shares available to trade
- Short interest
- 4.35% 1.8M shares short
- Days to cover
- 6.63 short interest up 7.3% vs prior month
- Institutions 52.56%
- Insiders 12.53%
- Other investors 34.91%
NBBK top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 7.60% | 3.3M | $72.8M | +247,322 (+8.0%) | June 30, 2026 |
| 2 | Vanguard Capital Management, LLC | 3.81% | 1.7M | $36.5M | −33,093 (−1.9%) | June 30, 2026 |
| 3 | AltraVue Capital, LLC | 3.78% | 1.7M | $36.2M | +351,028 (+26.9%) | June 30, 2026 |
| 4 | Pertento Partners LLP | 3.37% | 1.5M | $32.3M | −730,896 (−33.1%) | June 30, 2026 |
| 5 | State Street Corp | 3.36% | 1.5M | $32.2M | +178,228 (+13.8%) | June 30, 2026 |
| 6 | Geode Capital Management, LLC | 2.63% | 1.2M | $25.2M | +54,287 (+4.9%) | June 30, 2026 |
| 7 | Dimensional Fund Advisors, Inc. | 1.72% | 753K | $16.5M | +230,936 (+44.2%) | June 30, 2026 |
| 8 | The Goldman Sachs Group Inc | 1.31% | 572K | $12.5M | −119,714 (−17.3%) | June 30, 2026 |
| 9 | Tieton Capital Management, LLC | 1.25% | 547K | $11.9M | −6,970 (−1.3%) | June 30, 2026 |
| 10 | Hotchkis & Wiley Capital Management LLC | 1.14% | 501K | $11.0M | +50,400 (+11.2%) | June 30, 2026 |
| 11 | Nuveen, LLC | 1.14% | 499K | $10.9M | +10,836 (+2.2%) | June 30, 2026 |
| 12 | FMR Inc | 1.13% | 497K | $10.9M | +59,580 (+13.6%) | June 30, 2026 |
| 13 | Vanguard Portfolio Management, LLC | 0.91% | 397K | $8.7M | +10,914 (+2.8%) | June 30, 2026 |
| 14 | Legato Capital Management LLC | 0.84% | 366K | $8.0M | +90,020 (+32.6%) | June 30, 2026 |
| 15 | Northern Trust Corp | 0.82% | 360K | $7.9M | +25,132 (+7.5%) | June 30, 2026 |
| 16 | New York State Common Retirement Fund | 0.79% | 346K | $7.6M | +85,570 (+32.8%) | June 30, 2026 |
| 17 | Charles Schwab Investment Management Inc | 0.73% | 319K | $7.0M | +247 (+0.1%) | June 30, 2026 |
| 18 | Citadel Advisors Llc | 0.66% | 290K | $6.3M | +173,443 (+149.0%) | June 30, 2026 |
| 19 | Two Sigma Investments LLC | 0.63% | 277K | $6.1M | −94,780 (−25.5%) | June 30, 2026 |
| 20 | American Century Companies Inc | 0.60% | 262K | $5.7M | −1,790 (−0.7%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 14 holders added 1.6M shares and 6 cut 987K.
NBBK top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Vanguard MStar Total Stk Mkt Idx Invest | 2.72% | 1.2M | $26.1M | — | August 31, 2026 |
| 2 | iShares Russell 2000 ETF | 2.37% | 1.0M | $22.7M | +14,725 (+1.4%) | September 30, 2026 |
| 3 | Fidelity Enhanced Small Cap Core ETF | 1.03% | 452K | $9.9M | +948 (+0.2%) | September 30, 2026 |
| 4 | Fidelity Small Cap Index | 1.01% | 443K | $9.7M | +5,195 (+1.2%) | July 31, 2026 |
| 5 | CREF Total Global Stock Account R3 | 1.00% | 440K | $9.6M | — | July 31, 2026 |
| 6 | Avantis US Small Cap Value ETF | 0.96% | 421K | $9.2M | +3,888 (+0.9%) | September 30, 2026 |
| 7 | iShares Russell 2000 Value ETF | 0.84% | 367K | $8.0M | +556 (+0.2%) | September 30, 2026 |
| 8 | State Street® SPDR® S&PRgnllBkgETF | 0.82% | 359K | $7.9M | +10,752 (+3.1%) | September 30, 2026 |
| 9 | Vanguard Russell 2000 ETF | 0.53% | 234K | $5.1M | +5,561 (+2.4%) | August 31, 2026 |
| 10 | Schwab US Small-Cap ETF™ | 0.45% | 199K | $4.4M | +126 (+0.1%) | September 30, 2026 |
| 11 | Fidelity Extended Market Index | 0.43% | 189K | $4.1M | −2,695 (−1.4%) | August 31, 2026 |
| 12 | EA Bridgeway Omni Small-Cap Value ETF | 0.41% | 182K | $4.0M | — | September 30, 2026 |
| 13 | Hennessy Small Cap Financial Investor | 0.39% | 172K | $3.8M | −6,000 (−3.4%) | September 30, 2026 |
| 14 | Dimensional US Small Cap Value ETF | 0.39% | 170K | $3.7M | +206 (+0.1%) | September 24, 2026 |
| 15 | DFA US Small Cap Value I | 0.32% | 140K | $3.1M | +36,400 (+35.1%) | August 31, 2026 |
| 16 | Dimensional US Small Cap ETF | 0.32% | 139K | $3.0M | — | September 30, 2026 |
| 17 | DFA US Small Cap I | 0.29% | 129K | $2.8M | — | August 31, 2026 |
| 18 | iShares Micro-Cap ETF | 0.29% | 125K | $2.7M | −861 (−0.7%) | September 30, 2026 |
| 19 | Fidelity Small-Mid Multifactor ETF | 0.28% | 123K | $2.7M | — | September 30, 2026 |
| 20 | Fidelity VIP Disciplined Small Cap Init | 0.26% | 114K | $2.5M | — | July 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
NBBK insider transactions
latest 9| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-04-24 | Hope Pascucci | Buy | $19.46 | 20,000 | $389,200 |
| 2026-03-19 | Joseph P Campanelli | Buy | $20.16 | 2,500 | $50,400 |
| 2026-03-09 | Jean-Pierre Lapointe | Buy | $20.42 | 1,000 | $20,420 |
| 2026-03-06 | Joseph P Campanelli | Buy | $20.77 | 5,000 | $103,850 |
| 2025-10-28 | Hope Pascucci | Buy | $18.07 | 4,688 | $84,712 |
| 2025-07-25 | Paul A Evangelista | Buy | $18.39 | 500 | $9,195 |
| 2025-06-09 | Paul A Evangelista | Buy | $16.29 | 1,000 | $16,290 |
| 2025-05-02 | Mary Susan Elliott | Buy | $21.39 | 1,434 | $30,673 |
| 2025-04-29 | Francis Orfanello | Buy | $17.09 | 5,000 | $85,450 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
NBBK shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns NBBK
Institutional investors own 52.6% of NB Bancorp's shares and insiders 12.53%. The largest holder is BlackRock Inc with 7.60% of the shares (3.3M), as of June 30, 2026. Among the top 20 institutions, 14 added shares and 6 reduced their stake in the latest filings. Short interest is 4.35% of the float, or 6.63 days of average trading volume. The share count rose 6.7% since 2022.
Related: NBBK analyst forecast, NBBK key metrics, NBBK dividend history. See the NBBK stock overview for the latest quote and news.
NBBK ownership FAQ
Who owns the most NB Bancorp stock?
The largest shareholders of NB Bancorp are BlackRock Inc (7.60%), Vanguard Capital Management, LLC (3.81%), AltraVue Capital, LLC (3.78%), Pertento Partners LLP (3.37%), State Street Corp (3.36%).
What percentage of NB Bancorp is owned by institutions?
Institutions hold 52.6% of NB Bancorp's shares outstanding; insiders hold 12.53%.
Which funds own NB Bancorp?
The largest fund holders of NB Bancorp are Vanguard MStar Total Stk Mkt Idx Invest (2.72%), iShares Russell 2000 ETF (2.37%), Fidelity Enhanced Small Cap Core ETF (1.03%), Fidelity Small Cap Index (1.01%), CREF Total Global Stock Account R3 (1.00%).
What is NB Bancorp's short interest?
1.8M shares of NB Bancorp were sold short, 4.35% of the float; at the average daily volume it would take 6.63 days to cover.
Are insiders buying or selling NB Bancorp?
Of the latest 9 reported insider transactions in NB Bancorp (since April 29, 2025), 9 were purchases and 0 were sales.
How many shares of NB Bancorp are outstanding?
NB Bancorp has 43.8M shares outstanding, of which 37.1M are in the public float.