Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in NBBK held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 3.1M | $65.0M | -0.6% | 8.124% | 0.00% |
| 2 | Pertento Partners LLP | 2.2M | $46.5M | -5.9% | 5.813% | 4.93% |
| 3 | VANGUARD CAPITAL MANAGEMENT LLC | 1.7M | $35.9M | β | 4.488% | 0.00% |
| 4 | AltraVue Capital, LLC | 1.3M | $27.5M | +88.2% | 3.435% | 2.37% |
| 5 | STATE STREET CORP | 1.3M | $27.3M | +16.1% | 3.407% | 0.00% |
| 6 | GEODE CAPITAL MANAGEMENT, LLC | 1.1M | $23.2M | +13.7% | 2.895% | 0.00% |
| 7 | WELLINGTON MANAGEMENT GROUP LLP | 710K | $15.0M | -51.7% | 1.870% | 0.00% |
| 8 | GOLDMAN SACHS GROUP INC | 692K | $14.6M | +16.5% | 1.822% | 0.00% |
| 9 | DIMENSIONAL FUND ADVISORS LP | 522K | $11.0M | +81.4% | 1.376% | 0.00% |
| 10 | Nuveen, LLC | 488K | $10.3M | +40.7% | 1.286% | 0.00% |
| 11 | HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC | 451K | $9.5M | -35.8% | 1.187% | 0.03% |
| 12 | FMR LLC | 438K | $9.2M | +14.2% | 1.153% | 0.00% |
| 13 | VANGUARD PORTFOLIO MANAGEMENT LLC | 386K | $8.1M | β | 1.017% | 0.00% |
| 14 | TWO SIGMA INVESTMENTS, LP | 372K | $7.8M | +47.0% | 0.979% | 0.01% |
| 15 | NORTHERN TRUST CORP | 335K | $7.1M | +3.4% | 0.883% | 0.00% |
| 16 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 318K | $6.7M | -3.4% | 0.839% | 0.00% |
| 17 | SEI INVESTMENTS CO | 302K | $6.4M | +110.2% | 0.796% | 0.01% |
| 18 | MORGAN STANLEY | 280K | $5.9M | +15.6% | 0.737% | 0.00% |
| 19 | RENAISSANCE TECHNOLOGIES LLC | 264K | $5.6M | +5.0% | 0.695% | 0.01% |
| 20 | AMERICAN CENTURY COMPANIES INC | 264K | $5.6M | +18.8% | 0.695% | 0.00% |
| 21 | NEW YORK STATE COMMON RETIREMENT FUND | 261K | $5.5M | +80.5% | 0.686% | 0.01% |
| 22 | VANGUARD FIDUCIARY TRUST CO | 254K | $5.4M | β | 0.669% | 0.00% |
| 23 | BRIDGEWAY CAPITAL MANAGEMENT, LLC | 208K | $4.4M | +7.9% | 0.549% | 0.09% |
| 24 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | 184K | $3.9M | β | 0.485% | 0.00% |
| 25 | HENNESSY ADVISORS INC | 180K | $3.8M | -0.5% | 0.474% | 0.14% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in NBBK β a direct measure of their conviction.
Filings activity in NBBK during Q1 2026, grouped by how each filer changed its position.
Institutions that opened a new NBBK position in Q1 2026
Institutions that fully closed their NBBK position in Q1 2026
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 173 | +8.8% | 60.12% | +5.59 pp | $471M | +10% |
| Q4 2025 | 159 | +12% | 54.53% | +11.11 pp | $427M | +26% |
| Q3 2025 | 142 | +8.4% | 43.42% | +0.92 pp | $340M | +2.2% |
| Q2 2025 | 131 | +5.6% | 42.50% | +0.27 pp | $333M | +0.6% |
| Q1 2025 | 124 | +8.8% | 42.23% | +0.46 pp | $331M | +1.1% |
| Q4 2024 | 114 | +4.6% | 41.77% | 2.88 pp | $327M | 6.5% |
| Q3 2024 | 109 | +18% | 44.65% | +12.78 pp | $350M | +40% |
| Q2 2024 | 92 | β | 31.87% | β | $249M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying NBBK stock.
Based on Q1 2026 13F filings, institutional ownership of NB Bancorp, Inc. Common Stock stands at 60.1%, held across 173 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of NBBK, with approximately 3,084,222 shares worth $0.06B as of Q1 2026.
Yes β 3 widely-followed marquee investors appear among the top 25 institutional holders of NBBK, including TWO SIGMA INVESTMENTS, LP, RENAISSANCE TECHNOLOGIES LLC, SUSQUEHANNA INTERNATIONAL GROUP, LLP.
Our composite Smart Money Score for NBBK is 75 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
34 institutions opened new positions in NBBK during Q1 2026, while 20 fully exited. 112 added to existing positions and 27 trimmed.
NBBK institutional ownership rose by 5.59 percentage points quarter-over-quarter, with a net change of +14 holders.
The top 10 institutions account for 58.7% of all reported 13F value in NBBK, and the top 25 account for 78.8%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
NB Bancorp, Inc. Common Stock (NBBK) Institutional Ownership