Security Snapshot

NB Bancorp, Inc. - Common Stock, par value $0.01 per share (NBBK) Institutional Ownership

CUSIP: 63945M107

13F Institutional Holders and Ownership History from Q4 2023 to Q1 2026

Latest Period

Q1 2026

Institutions Reporting

176

Shares (Excl. Options)

23,080,458

Price

$21.07

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Type / Class
Equity / Common Stock, par value $0.01 per share
Symbol
NBBK on Nasdaq
Shares outstanding
44,556,826
Price per share
$22.25
All holders as of 31 Mar 2026
Q1 2026
Total 13F shares
23,080,458
Total reported value
$486,184,309
% of total 13F portfolios
0%
Share change
+754,160
Value change
+$16,858,165
Number of holders
176
Price from insider filings
$22.25
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Key facts

  • NBBK - NB Bancorp, Inc. - Common Stock, par value $0.01 per share is tracked under CUSIP 63945M107.
  • 176 institutions reported positions in Q1 2026.
  • 3 significant owners is listed from Schedule 13D/13G reporting.

Change

  • Holder count moved from 163 to 176 between Q4 2025 and Q1 2026.
  • Reported value moved from $441,285,654 to $486,184,309.

Research use

  • You can quickly see who holds this security, then open quarter and manager detail pages for full evidence.
  • 13F and Schedule 13D/13G sections are kept together so you can cross-check institutional and beneficial ownership context.

Evidence

Source: SEC Form 13F

Latest holder context comes from 176 institutions filings for Q1 2026.

Open SEC Evidence

Security key

63945M107

Latest holder period

Q1 2026

13F holders

176

13D/G owners

3

CIK / CUSIP context first

Open Q1 2026 holders NBBK full holder history NB Bancorp, Inc. SEC filings NB Bancorp, Inc. company facts NB Bancorp, Inc. insider transactions

Broader feeds

Latest 13F filings Latest 13D/G filings All securities

Significant Owners of NB Bancorp, Inc. - Common Stock, par value $0.01 per share (NBBK) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
Needham Bank Employee Stock Ownership Plan Trust 7.5% $67,543,375 3,416,458 Needham Bank Employee Stock Ownership Plan Trust 31 Dec 2025
BlackRock, Inc. 6.7% $47,015,321 2,663,833 BlackRock, Inc. 30 Sep 2025
Pertento Partners LLP 4.6% -10% $43,185,367 -$6,097,089 2,049,614 -12% Pertento Partners LLP 31 Mar 2026

As of 31 Mar 2026, 176 institutional investors reported holding 23,080,458 shares of NB Bancorp, Inc. - Common Stock, par value $0.01 per share (NBBK). This represents 52% of the company’s total 44,556,826 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of NB Bancorp, Inc. - Common Stock, par value $0.01 per share (NBBK) together control 41% of the company’s outstanding shares — a level of ownership often associated with strong institutional conviction and long‑term capital commitment.

Institution Ownership % Shares Held Share Change % Portfolio % Holdings Value
BlackRock, Inc. 6.9% 3,084,222 -0.63% 0% $64,984,549
Pertento Partners LLP 5% 2,206,666 -5.8% 4.9% $46,494,453
VANGUARD CAPITAL MANAGEMENT LLC 3.8% 1,703,928 0% 0% $35,901,763
AltraVue Capital, LLC 2.9% 1,304,080 +88% 2.4% $27,476,966
STATE STREET CORP 2.9% 1,293,538 +16% 0% $27,254,846
GEODE CAPITAL MANAGEMENT, LLC 2.5% 1,098,930 +14% 0% $23,159,188
WELLINGTON MANAGEMENT GROUP LLP 1.6% 710,000 -52% 0% $14,959,700
GOLDMAN SACHS GROUP INC 1.6% 691,668 +16% 0% $14,573,447
Tieton Capital Management, LLC 1.2% 553,570 +5.5% 3.9% $11,664,000
DIMENSIONAL FUND ADVISORS LP 1.2% 522,384 +81% 0% $11,005,796
Nuveen, LLC 1.1% 488,033 +41% 0% $10,282,856
HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC 1% 450,772 -36% 0.03% $9,497,766
FMR LLC 0.98% 437,725 +14% 0% $9,222,866
VANGUARD PORTFOLIO MANAGEMENT LLC 0.87% 386,132 0% 0% $8,135,801
TWO SIGMA INVESTMENTS, LP 0.83% 371,807 +47% 0.01% $7,833,973
NORTHERN TRUST CORP 0.75% 335,360 +3.4% 0% $7,066,034
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.71% 318,365 -3.3% 0% $6,707,951
SEI INVESTMENTS CO 0.68% 302,181 +110% 0.01% $6,366,955
MORGAN STANLEY 0.63% 279,870 +16% 0% $5,896,862
Legato Capital Management LLC 0.62% 276,070 +61% 0.53% $5,816,795
RENAISSANCE TECHNOLOGIES LLC 0.59% 263,906 +5% 0.01% $5,560,499
AMERICAN CENTURY COMPANIES INC 0.59% 263,656 +19% 0% $5,555,232
NEW YORK STATE COMMON RETIREMENT FUND 0.58% 260,585 +80% 0.01% $5,490,526
VANGUARD FIDUCIARY TRUST CO 0.57% 254,038 0% 0% $5,352,581
BRIDGEWAY CAPITAL MANAGEMENT, LLC 0.47% 208,394 +7.9% 0.09% $4,390,862

Institutional Holders of NB Bancorp, Inc. - Common Stock, par value $0.01 per share (NBBK) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2026 Q1 23,080,458 $486,184,309 +$16,858,165 $21.07 176
2025 Q4 22,272,633 $441,285,654 +$62,746,915 $19.82 163
2025 Q3 19,191,470 $338,803,226 +$8,507,888 $17.65 144
2025 Q2 18,717,578 $334,367,604 +$6,692,709 $17.86 129
2025 Q1 18,345,847 $331,321,498 +$4,235,296 $18.07 120
2024 Q4 18,099,643 $326,677,743 -$12,909,221 $18.06 113
2024 Q3 18,798,787 $348,790,411 +$34,867,490 $18.56 106
2024 Q2 16,756,519 $253,194,867 +$107,038,595 $15.08 91
2024 Q1 9,585,291 $131,014,856 +$95,658,320 $13.66 55
2023 Q4 2,575,613 $34,675,619 +$30,437,121 $13.45 17
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