OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG) Institutional Ownership

13F Institutional Holders and Ownership History from Q1 2014 to Q4 2025

Type / Class
Equity / Common Stock, $0.01 par value per share
Symbol
OSG on NYSE
Shares outstanding
46,241,273
Price per share
$7.78
All holders as of 30 Sep 2025
Q3 2025
Total 13F shares
36,420,468
Total reported value
$303,620,015
% of total 13F portfolios
0%
Share change
+233,587
Value change
+$5,517,669
Number of holders
125
Price from insider filings
$7.78
Reported Shares, Excluding Options vs Price
Reported Value, Excluding Options
Total Investors

Significant Owners of OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG) based on Schedule 13D/G filings

Filer Ownership Change % Holdings Value Net Change Nb Shares Change % Reporting Name Report Period
BlackRock, Inc. 7.6% -12% $29,497,691 -$3,891,879 3,535,664 -12% BlackRock, Inc. 30 Sep 2025
VANGUARD GROUP INC 5.8% -15% $17,428,777 -$3,636,337 2,660,882 -17% The Vanguard Group 31 Mar 2025
DIMENSIONAL FUND ADVISORS LP 4.6% $17,855,690 2,141,047 Dimensional Fund Advisors LP 30 Sep 2025
SUSQUEHANNA SECURITIES, LLC 2.2% -58% $8,484,349 -$11,354,702 1,017,308 -57% G1 Execution Services, LLC 30 Sep 2025

As of 30 Sep 2025, 125 institutional investors reported holding 36,420,468 shares of OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG). This represents 79% of the company’s total 46,241,273 outstanding shares.

Top 25 Institutional Shareholders

The largest institutional shareholders of OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG) together control 67% 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. 9.7% 4,493,331 -2.1% 0% $37,474,381
Western Standard LLC 5.7% 2,641,351 12% $22,028,867
VANGUARD GROUP INC 5.5% 2,555,181 -0.52% 0% $21,310,209
DIMENSIONAL FUND ADVISORS LP 4.6% 2,141,047 -11% 0% $17,860,855
CONTINENTAL GENERAL INSURANCE CO 4.5% 2,068,349 +70% 3.3% $17,250,031
GENDELL JEFFREY L 4% 1,864,512 +56% 0.29% $15,550,030
FMR LLC 3.3% 1,525,423 -0.47% 0% $12,722,027
Wolf Hill Capital Management, LP 2.5% 1,158,197 +67% 0.92% $9,659,363
Caption Management, LLC 2.4% 1,121,179 +537% 0.54% $9,350,633
Bain Capital Credit, LP 2.4% 1,108,012 0% 2.9% $9,240,820
Nuveen, LLC 2.3% 1,079,328 +131% 0% $9,001,596
GEODE CAPITAL MANAGEMENT, LLC 2.3% 1,060,594 -5.5% 0% $8,847,450
STATE STREET CORP 2.1% 967,188 +0.87% 0% $8,066,348
Prescott Group Capital Management, L.L.C. 1.9% 895,977 +2.3% 0.79% $7,472,448
JANE STREET GROUP, LLC 1.8% 849,182 +66% 0.01% $7,082,177
MILLENNIUM MANAGEMENT LLC 1.5% 700,895 -30% 0% $5,845,464
BARCLAYS PLC 1.4% 669,513 +47% 0% $5,583,740
THIRD AVENUE MANAGEMENT LLC 1.3% 603,391 0% 0.92% $4,905,569
Bracebridge Capital, LLC 1.3% 579,234 0% 2% $4,830,812
Schonfeld Strategic Advisors LLC 1.2% 548,442 +92% 0.03% $4,574,006
DEUTSCHE BANK AG\ 1.2% 532,138 -18% 0% $4,438,031
GOLDMAN SACHS GROUP INC 1.1% 524,890 +9.5% 0% $4,377,583
MARSHALL WACE, LLP 0.98% 455,074 -30% 0% $3,795,318
CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.83% 382,572 -1.4% 0% $3,190,650
NORTHERN TRUST CORP 0.78% 362,021 -6.9% 0% $3,019,255

Institutional Holders of OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG) across Reporting Periods

Period Reported Shares, Excl. Options Value, Excl. Options Value Change Price (Median) Investors
2025 Q4 407,994 $3,174,212 +$2,452,691 $7.78 8
2025 Q3 36,420,468 $303,620,015 +$5,517,669 $8.34 125
2025 Q2 36,967,187 $262,451,287 -$6,275,013 $7.10 145
2025 Q1 37,285,182 $325,246,936 -$39,528,299 $8.75 170
2024 Q4 41,462,873 $522,332,892 +$18,984,311 $12.65 179
2024 Q3 40,010,867 $446,675,630 +$7,156,204 $11.21 179
2024 Q2 38,736,820 $496,580,829 +$11,208,682 $12.82 184
2024 Q1 37,776,388 $590,297,768 -$4,918,197 $15.63 171
2023 Q4 165,627 $2,729,533 -$1,231,831 $16.48 1
2023 Q3 36,268,044 $437,839,867 -$11,466,641 $12.06 164
2023 Q2 37,133,704 $528,235,613 -$27,669,278 $14.24 158
2023 Q1 38,580,360 $596,164,201 +$63,968,631 $15.48 156
2022 Q4 34,463,763 $600,316,814 +$61,551,974 $17.44 163
2022 Q3 31,281,667 $398,978,183 -$49,971,786 $12.75 144
2022 Q2 30,157,360 $341,660,154 -$36,450,150 $11.35 134
2022 Q1 31,354,560 $325,360,695 -$4,859,392 $10.40 138
2021 Q4 37,031,145 $593,935,108 +$12,957,589 $16.05 126
2021 Q3 35,916,924 $514,291,696 -$1,614,143 $14.32 126
2021 Q2 35,960,905 $562,886,596 -$8,566,736 $15.66 121
2021 Q1 36,393,038 $609,458,331 -$26,708,456 $16.74 135
2020 Q4 35,908,767 $552,294,561 -$5,603,801 $15.38 131
2020 Q3 34,461,068 $439,847,199 -$16,903,911 $12.77 123
2020 Q2 37,191,275 $532,453,958 +$19,509,659 $14.32 132
2020 Q1 35,774,354 $441,457,094 -$9,241,601 $12.34 119
2019 Q4 36,662,365 $790,534,535 +$9,325,899 $21.57 129
2019 Q3 35,972,605 $703,213,865 -$19,194,568 $19.55 123
2019 Q2 35,696,963 $601,478,318 +$22,080,461 $16.85 127
2019 Q1 34,236,934 $620,358,503 -$20,961,919 $18.12 149
2018 Q4 36,102,989 $622,331,596 +$43,592,297 $17.24 141
2018 Q3 35,348,679 $721,762,264 -$25,520,630 $20.42 150
2018 Q2 36,584,573 $726,239,584 +$48,884,886 $19.85 141
2018 Q1 33,954,130 $532,275,869 +$6,929,319 $15.68 110
2017 Q4 32,465,914 $518,750,390 -$8,815,635 $15.98 112
2017 Q3 31,755,643 $548,132,061 -$23,888,000 $17.26 117
2017 Q2 33,149,075 $575,094,561 -$6,659,534 $17.35 124
2017 Q1 33,358,181 $629,115,540 +$44,012,658 $18.86 141
2016 Q4 32,788,008 $737,680,333 -$6,130,230 $22.50 147
2016 Q3 32,064,545 $589,656,481 -$10,052,924 $18.39 118
2016 Q2 30,395,130 $500,291,933 +$5,102,619 $16.46 123
2016 Q1 32,129,131 $507,532,305 -$25,264,299 $15.80 113
2015 Q4 34,137,929 $480,990,372 -$4,614,893 $14.09 126
2015 Q3 34,366,781 $497,137,270 -$3,990,887 $14.47 124
2015 Q2 34,323,878 $570,956,495 +$5,175,419 $16.64 123
2015 Q1 33,602,165 $813,115,265 +$33,209,375 $24.20 120
2014 Q4 31,376,854 $768,581,251 -$48,379,163 $24.50 119
2014 Q3 34,599,203 $764,613,645 -$50,119,396 $22.10 113
2014 Q2 36,118,453 $986,406,496 +$9,074,239 $27.31 121
2014 Q1 35,737,453 $1,108,815,595 +$118,510,152 $31.03 132