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

13F Institutional Holders and Ownership History from Q4 2023 to Q4 2025

Type / Class
Equity / Common Stock, par value $0.01 per share
Symbol
NBBK on Nasdaq
Shares outstanding
45,862,490
Price per share
$19.82
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
19,191,466
Total reported value
$338,803,297
% of total 13F portfolios
0%
Share change
+483,980
Value change
+$8,508,488
Number of holders
144
Price from insider filings
$19.82
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

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
BlackRock, Inc. 6.7% $47,015,321 2,663,833 BlackRock, Inc. 30 Sep 2025
Pertento Partners LLP 5.1% -2% $41,633,969 +$3,998,788 2,338,987 +11% Pertento Partners LLP 01 Dec 2025
VANGUARD GROUP INC 4.9% -3% $35,398,449 -$2,263,951 1,981,996 -6% The Vanguard Group 30 Jun 2025

As of 30 Sep 2025, 144 institutional investors reported holding 19,191,466 shares of NB Bancorp, Inc. - Common Stock, par value $0.01 per share (NBBK). This represents 42% of the company’s total 45,862,490 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 34% 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. 6.2% 2,822,125 -2.1% 0% $49,810,508
Pertento Partners LLP 4.6% 2,114,336 0% 4.5% $37,318,030
VANGUARD GROUP INC 4.3% 1,950,135 -1.6% 0% $34,419,883
WELLINGTON MANAGEMENT GROUP LLP 4% 1,826,939 -1.8% 0.01% $32,245,473
STATE STREET CORP 2.6% 1,196,922 +6.8% 0% $21,125,673
GEODE CAPITAL MANAGEMENT, LLC 1.9% 876,648 -0.74% 0% $15,475,514
HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC 1.5% 694,982 +27% 0.04% $12,266,432
MILLENNIUM MANAGEMENT LLC 1.2% 543,282 -16% 0.01% $9,588,927
GOLDMAN SACHS GROUP INC 1.1% 524,898 +11% 0% $9,264,451
UBS Group AG 0.82% 378,353 +264% 0% $6,677,930
FMR LLC 0.71% 324,680 +7.8% 0% $5,730,603
NORTHERN TRUST CORP 0.68% 309,699 -2.2% 0% $5,466,187
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.63% 287,455 -3.9% 0% $5,073,581
MARSHALL WACE, LLP 0.6% 277,100 -12% 0.01% $4,890,813
TWO SIGMA INVESTMENTS, LP 0.45% 205,869 +46% 0.01% $3,633,588
HENNESSY ADVISORS INC 0.4% 185,000 +2.8% 0.11% $3,265,250
EJF Capital LLC 0.38% 172,803 +3% 1.8% $3,049,973
PANAGORA ASSET MANAGEMENT INC 0.38% 172,662 -23% 0.01% $3,047,484
PROSPECTOR PARTNERS LLC 0.33% 150,862 -10% 0.32% $2,662,714
AMERICAN CENTURY COMPANIES INC 0.3% 137,313 +122% 0% $2,423,574
TWO SIGMA ADVISERS, LP 0.29% 134,100 +49% 0% $2,366,865
Financial Engines Advisors L.L.C. 0.28% 129,288 +9.3% 0% $2,281,933
FIRST TRUST ADVISORS LP 0.27% 125,469 +377% 0% $2,214,527
MORGAN STANLEY 0.27% 122,069 -9.1% 0% $2,154,518
JPMORGAN CHASE & CO 0.26% 119,682 +20% 0% $2,112,388

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
2025 Q4 118,089 $2,333,833 +$118,795 $19.82 10
2025 Q3 19,191,466 $338,803,297 +$8,508,488 $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