Octave Specialty GroupOSG

13F holders, Q3 2025 (September 30)
130holders −16
22new positions
35sold out
6famous investors
$14.33avg. 13F price*

At the end of Q3 2025, 130 institutions reported holding Octave Specialty Group Inc. (OSG) in their 13F filings, down 16 from Q2 2025. 22 opened new positions and 35 sold out. The largest holders were Manufacturers Life Insurance Company, The ($232.0M), BlackRock, Inc. ($37.5M) and Western Standard LLC ($22.0M). 6 famous investors held it, including Paul Tudor Jones (0.0% of Tudor Investment Corporation's portfolio), Israel Englander (0.0% of Millennium Management's portfolio) and Ken Griffin (0.0% of Citadel Advisors's portfolio).

Company
Octave Specialty Group Inc.
Filed as
AMBAC FINL GROUP INC (Q3 2025)
CUSIP
023139884
Latest filing quarter
Q2 2026

History

Number of 13F holders

050100150200 Q1 2024: 172Q1 2024Q2 2024: 182Q2 2024Q3 2024: 180Q3 2024Q4 2024: 180Q4 2024Q1 2025: 175Q1 2025Q2 2025: 146Q2 2025Q3 2025: 130Q3 2025Q4 2025: 144Q4 2025Q1 2026: 148Q1 2026Q2 2026: 147Q2 2026

Total Exit/New Position Q2 2025 → Q3 2025

InstitutionsTotal Value
New Positions22$27.8M
Exits35$19.1M

All 13F filers, Q2 2025 → Q3 2025: 9,337,266 shares bought and 7,757,240 shares sold, net +1,580,026 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.

Ownership 130 holders

Manufacturers Life Insurance Company, The 0.19% Add +6604.6% 1,206,350 $232.0M
BlackRock, Inc. 0.00% Reduce -2.1% 4,493,331 $37.5M
Western Standard LLC 11.78% New 2,641,351 $22.0M
Vanguard Group Inc. 0.00% Reduce -0.5% 2,555,181 $21.3M
Dimensional Fund Advisors LP 0.00% Reduce -10.6% 2,141,047 $17.9M
Continental General Insurance Co. 3.35% Add +69.8% 2,068,349 $17.3M
Gendell Jeffrey L 0.29% Add +55.6% 1,864,512 $15.6M
FMR LLC 0.00% Reduce -0.5% 1,525,423 $12.7M
Wolf Hill Capital Management, LP 0.92% Add +67.0% 1,158,197 $9.7M
Caption Management, LLC 0.57% Add +536.8% 1,121,179 $9.4M
Bain Capital Credit, LP 2.91% No change 1,108,012 $9.2M
Nuveen, LLC 0.00% Add +131.1% 1,079,328 $9.0M
Geode Capital Management, LLC 0.00% Reduce -5.5% 1,060,594 $8.8M
State Street Corp. 0.00% Add +0.9% 967,188 $8.1M
Prescott Group Capital Management, L.L.C. 0.79% Add +2.3% 895,977 $7.5M
Jane Street Group, LLC 0.01% Add +65.7% 849,182 $7.1M
Millennium Management 0.00% Reduce -29.6% 700,895 $5.8M
Barclays PLC 0.00% Add +47.2% 669,513 $5.6M
Third Avenue Management LLC 0.92% No change 603,391 $4.9M
Bracebridge Capital, LLC 2.11% No change 579,234 $4.8M
Schonfeld Strategic Advisors LLC 0.03% Add +92.0% 548,442 $4.6M
Deutsche Bank AG 0.00% Reduce -17.5% 532,138 $4.4M
Goldman Sachs Group Inc. 0.00% Add +9.5% 524,890 $4.4M
Marshall Wace, LLP 0.00% Reduce -29.8% 455,074 $3.8M
Franklin Resources Inc. 0.00% Add +60.0% 17,080 $3.8M
Charles Schwab Investment Management Inc. 0.00% Reduce -1.4% 382,572 $3.2M
Northern Trust Corp. 0.00% Reduce -6.9% 362,021 $3.0M
Bridgeway Capital Management, LLC 0.06% Add +0.7% 319,493 $2.7M
UBS Group AG 0.00% Reduce -22.4% 279,489 $2.3M
Susquehanna International Group, LLP 0.00% Reduce -70.8% 274,310 $2.3M
Empowered Funds, LLC 0.02% Add +13.2% 234,493 $2.0M
Bank of America Corp. 0.00% Add +22.2% 203,202 $1.7M
Arrowpoint Investment Partners (Singapore) Pte. Ltd. 2.52% New 203,011 $1.7M
Harbor Advisors LLC 0.25% No change 196,382 $1.6M
Morgan Stanley 0.00% Reduce -57.6% 194,124 $1.6M
VELA Investment Management, LLC 0.43% Add +46.7% 180,089 $1.5M
Squarepoint Ops LLC 0.00% Reduce -62.5% 175,017 $1.5M
Citadel Advisors 0.00% Reduce -84.7% 171,543 $1.4M
Invesco Ltd. 0.00% Reduce -3.7% 164,081 $1.4M
Y-Intercept (Hong Kong) Ltd 0.03% Reduce -57.1% 150,489 $1.3M
Bank of New York Mellon Corp 0.00% Reduce -2.3% 138,687 $1.2M
Trexquant Investment LP 0.01% Reduce -56.9% 136,696 $1.1M
American Century Companies Inc. 0.00% Reduce -69.7% 132,648 $1.1M
Tudor Investment Corporation 0.01% Reduce -59.1% 125,155 $1.0M
D. E. Shaw & Co. 0.00% Reduce -64.6% 118,725 $990K
Cruiser Capital Advisors, LLC 0.93% New 111,800 $932K
Connor, Clark & Lunn Investment Management Ltd. 0.00% Reduce -5.0% 105,465 $880K
HSBC Holdings PLC 0.00% Add +6.5% 103,668 $828K
IMC-Chicago, LLC 0.01% Reduce -30.9% 97,422 $812K
Creative Planning 0.00% Add +342.2% 90,303 $753K
Renaissance Technologies 0.00% Reduce -52.1% 89,200 $744K
BNP Paribas Financial Markets 0.00% Reduce -25.4% 89,147 $743K
AQR Capital Management 0.00% Add +60.9% 82,562 $689K
Balyasny Asset Management L.P. 0.00% New 81,221 $677K
DLD Asset Management, LP 0.28% Add +58.6% 79,300 $661K
SG Americas Securities, LLC 0.00% Add +248.5% 75,415 $629K
Wells Fargo & Company 0.00% Add +2.9% 73,857 $616K
Empirical Finance, LLC 0.03% No change 72,182 $602K
T. Rowe Price Associates Inc. 0.00% Add +35.9% 70,941 $592K
Sender Co & Partners, Inc. 0.23% New 70,890 $591K
Rhumbline Advisers 0.00% Reduce -10.3% 67,170 $560K
Caxton Associates LLP 0.01% No change 65,647 $547K
Diametric Capital, LP 0.20% New 64,626 $539K
Prudential Financial Inc. 0.00% New 56,625 $472K
Quantinno Capital Management LP 0.00% Add +40.0% 40,353 $337K
Alliancebernstein L.P. 0.00% No change 37,530 $313K
Brevan Howard Capital Management LP 0.00% Reduce -30.0% 35,485 $296K
JPMorgan Chase & Co. 0.00% Add +10.6% 34,555 $288K
Quarry LP 0.06% Add +1572.0% 26,000 $217K
Wolverine Trading, LLC 0.00% New 21,298 $207K
KLCM Advisors, Inc. 0.02% No change 24,000 $200K
Intech Investment Management LLC 0.00% Reduce -45.6% 22,520 $188K
Cresset Asset Management, LLC 0.00% No change 22,193 $185K
Gator Capital Management, LLC 0.05% No change 21,435 $179K
Simplex Trading, LLC 0.00% Reduce -33.1% 20,878 $174K
Verition Fund Management LLC 0.00% Reduce -47.8% 20,533 $171K
Group One Trading LLC 0.01% Reduce -93.6% 20,449 $171K
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. 0.00% Reduce -23.7% 20,052 $167K
MetLife Investment Management, LLC 0.00% New 18,353 $153K
Mraz, Amerine & Associates, Inc. 0.02% Reduce -3.2% 18,250 $152K
Prelude Capital Management, LLC 0.01% New 17,878 $149K
ExodusPoint Capital Management, LP 0.00% Reduce -69.3% 14,159 $118K
Ieq Capital, LLC 0.00% Add +0.3% 13,702 $114K
State Board of Administration of Florida Retirement System 0.00% No change 12,630 $105K
Aquatic Capital Management LLC 0.00% New 12,588 $105K
Police & Firemen's Retirement System of New Jersey 0.00% Add +28.5% 11,825 $99K
Cerity Partners LLC 0.00% Reduce -3.0% 11,490 $96K
FNY Investment Advisers, LLC 0.03% New 11,207 $93K
New York State Common Retirement Fund 0.00% No change 10,073 $84K
Citigroup Inc. 0.00% Reduce -59.4% 9,341 $78K
Cwm, LLC 0.00% Add +75.7% 6,961 $58K
Arax Advisory Partners 0.00% New 6,614 $55K
Russell Investments Group, Ltd. 0.00% Add +613.5% 4,916 $41K
Federated Hermes, Inc. 0.00% Reduce -15.5% 4,420 $37K
Legal & General Group Plc 0.00% Reduce -10.8% 3,839 $32K
Ameritas Investment Partners, Inc. 0.00% Reduce -20.4% 3,648 $30K
Sterling Capital Management LLC 0.00% Add +144.1% 2,978 $25K
California State Teachers Retirement System 0.00% New 2,974 $25K
State of Wyoming 0.00% Reduce -82.2% 2,589 $22K
Quadrant Capital Group LLC 0.00% New 2,483 $21K
Royal Bank of Canada 0.00% Reduce -95.5% 2,343 $20K
Tower Research Capital LLC (TRC) 0.00% Add +58.1% 2,387 $20K
Cove Street Capital, LLC 0.02% New 1,861 $16K
Versant Capital Management, Inc 0.00% No change 1,619 $14K
Amalgamated Bank 0.00% No change 1,567 $13K
Harbor Capital Advisors, Inc. 0.00% Add +2.3% 1,150 $10K
MAI Capital Management 0.00% New 1,064 $9K
Nisa Investment Advisors, LLC 0.00% Reduce -4.7% 970 $8K
US Bancorp \de 0.00% Add +232.6% 755 $6K
Signaturefd, LLC 0.00% Add +550.0% 754 $6K
Advisors Asset Management, Inc. 0.00% Reduce -1.0% 101 $6K
GAMMA Investing LLC 0.00% Reduce -17.5% 627 $5K
Wiser Advisor Group LLC 0.01% New 500 $4K
Optiver Holding B.V. 0.00% New 424 $4K
Allworth Financial LP 0.00% Add +184.7% 390 $3K
National Bank of Canada 0.00% Add +5400.0% 385 $3K
Capital Analysts, LLC 0.00% No change 325 $3K
Parallel Advisors, LLC 0.00% Add +1633.3% 260 $2K
DiNuzzo Private Wealth, Inc. 0.00% No change 177 $2K
PNC Financial Services Group, Inc. 0.00% Add +41.6% 143 $1K
Principal Securities, Inc. 0.00% New 120 $1K
Farther Finance Advisors, LLC 0.00% New 105 $876
EverSource Wealth Advisors, LLC 0.00% Add +41.2% 72 $600
Rothschild Investment LLC 0.00% Add +93.8% 62 $517
True Wealth Design, LLC 0.00% Add +45.7% 51 $426
Osaic Holdings, Inc. 0.00% No change 26 $234
Legacy Wealth Managment, LLC 0.00% No change 25 $209
IFP Advisors, Inc 0.00% Add +0.0% 15 $125
Essential Partners LLC 0.00% New 14 $117
SBI Securities Co., Ltd. 0.00% Reduce -97.3% 12 $100

"% of holder's portfolio" is OSG's weight in each manager's 13F, not the share of Octave Specialty Group Inc. the manager owns.