Latest Period
Q1 2026
Security Snapshot
OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG) Institutional Ownership
CUSIP: 023139884
13F Institutional Holders and Ownership History from Q1 2014 to Q1 2026
Institutions Reporting
146
Shares (Excl. Options)
32,501,286
Price
$4.65
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- Security type / class
- Equity / Common Stock, $0.01 par value per share
- Symbol
- OSG on NYSE
- All holders as of 31 Mar 2026
- Q1 2026
- Total 13F shares
- 32,501,286
- Total 13F value
- $151,121,666
- Portfolio coverage rank
- 0%
- Share change
- -2,112,814
- Value change
- -$13,743,438
- Number of holders
- 146
- Shares outstanding
- 45,041,904
- SEC-reported price per share
- $5.85
- Insider filing price
- $5.85
Latest holder snapshot
5 signals
Issuer context
Names, identifiers, and filing context for this profile.
3 identity fields
13F Shares, Excluding Options vs Price
13F Value, Excluding Options
Total Investors
Key facts
- OSG - OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share is tracked under CUSIP 023139884.
- 146 institutions reported positions in Q1 2026.
- 5 significant owners is listed from Schedule 13D/13G reporting.
Change
- Holder count moved from 144 to 146 between Q4 2025 and Q1 2026.
- SEC-reported value moved from $270,000,146 to $151,121,666.
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
Open SEC evidence
Latest holder context comes from 146 institutions filings for Q1 2026.
Security key
023139884
Latest holder period
Q1 2026
13F holders
146
13D/G owners
5
CIK / CUSIP context first
Open Q1 2026 holders
OSG full holder history
OCTAVE SPECIALTY GROUP INC SEC filings
OCTAVE SPECIALTY GROUP INC company facts
OCTAVE SPECIALTY GROUP INC insider transactions
Broader feeds
Recent Quarterly Holder Reports
Open recent reporting periods for CUSIP 023139884:
13D/G owners
Significant owners
Large-stake holder rows connected to Schedule 13D/G evidence.
Rows
5
Security
OSG
| 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 |
| Western Standard LLC | 5% | -15% | $10,451,298 | -$1,510,576 | 2,247,591 | -13% | Western Standard LLC | 31 Mar 2026 |
| 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 |
| JANE STREET GROUP, LLC | 1.7% | -74% | $3,586,936 | -$7,469,620 | 771,384 | -68% | JANE STREET GROUP, LLC | 31 Mar 2026 |
As of 31 Mar 2026, 146 institutional investors reported holding 32,501,286 shares of OCTAVE SPECIALTY GROUP INC - Common Stock, $0.01 par value per share (OSG). This represents 72% of the company’s total 45,041,904 outstanding shares.
13F concentration
Top 25 institutional shareholders
Largest 13F positions for this security by reported shares and value.
Top holder share
58%
| Institution | Ownership % | Shares Held | Share Change % | Portfolio % | Holdings Value |
|---|---|---|---|---|---|
| BlackRock, Inc. | 8.7% | 3,917,798 | -13% | 0% | $18,217,762 |
| Western Standard LLC | 5% | 2,247,591 | -10% | 5.5% | $10,451,298 |
| VANGUARD CAPITAL MANAGEMENT LLC | 4.3% | 1,945,076 | 0% | 0% | $9,044,603 |
| Prescott Group Capital Management, L.L.C. | 3.5% | 1,592,587 | +78% | 0.74% | $7,405,530 |
| Wolf Hill Capital Management, LP | 3.3% | 1,470,334 | -22% | 0.97% | $6,837,053 |
| GENDELL JEFFREY L | 3.1% | 1,413,212 | -10% | 0.09% | $6,571,436 |
| THIRD AVENUE MANAGEMENT LLC | 3% | 1,341,211 | +71% | 1% | $6,236,631 |
| DIMENSIONAL FUND ADVISORS LP | 2.9% | 1,310,132 | -22% | 0% | $6,092,068 |
| Bain Capital Credit, LP | 2.5% | 1,108,012 | 0% | 1.7% | $5,152,256 |
| MARSHALL WACE, LLP | 2.4% | 1,065,335 | +42% | 0.01% | $4,953,807 |
| GEODE CAPITAL MANAGEMENT, LLC | 2.3% | 1,022,438 | -0.21% | 0% | $4,755,504 |
| STATE STREET CORP | 2.1% | 941,404 | -0.21% | 0% | $4,377,529 |
| JACOBS LEVY EQUITY MANAGEMENT, INC | 2% | 884,272 | +273% | 0.02% | $4,111,865 |
| Nuveen, LLC | 1.8% | 800,253 | -1.2% | 0% | $3,721,176 |
| JANE STREET GROUP, LLC | 1.7% | 764,384 | -50% | 0% | $3,554,385 |
| Caption Management, LLC | 1.4% | 642,597 | -40% | 0.14% | $2,988,076 |
| Bracebridge Capital, LLC | 1.3% | 579,234 | 0% | 0.48% | $2,693,438 |
| RIHO Partners, LLC | 1.2% | 546,569 | 1.6% | $2,541,546 | |
| CITADEL ADVISORS LLC | 0.96% | 431,809 | +50% | 0% | $2,007,912 |
| ESSEX INVESTMENT MANAGEMENT CO LLC | 0.93% | 418,203 | +1.8% | 0.31% | $1,944,644 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP | 0.87% | 390,193 | -26% | 0% | $1,814,397 |
| GOLDMAN SACHS GROUP INC | 0.77% | 346,293 | -56% | 0% | $1,610,263 |
| IPG Investment Advisors LLC | 0.72% | 325,616 | 0.26% | $1,514,114 | |
| Brooklyn Investment Group | 0.72% | 325,351 | 0.05% | $1,512,883 | |
| NORTHERN TRUST CORP | 0.72% | 322,348 | -0.25% | 0% | $1,498,918 |
Quarter history
Institutional holders across reporting periods
Holder count, reported shares/value, and median price by quarter.
Periods
49
Latest
Q1 2026
Rows shown
1-25 of 49
| Period | 13F Shares, Excl. Options | Value, Excl. Options | Value Change | Price (Median) | Investors |
|---|---|---|---|---|---|
| 2026 Q1 | 32,501,286 | $151,121,666 | -$13,743,438 | $4.65 | 146 |
| 2025 Q4 | 34,704,270 | $270,000,146 | -$15,016,916 | $7.78 | 144 |
| 2025 Q3 | 36,420,483 | $303,620,140 | +$5,517,493 | $8.34 | 126 |
| 2025 Q2 | 36,967,187 | $262,451,287 | -$6,275,007 | $7.10 | 145 |
| 2025 Q1 | 37,285,182 | $325,247,075 | -$39,529,091 | $8.75 | 170 |
| 2024 Q4 | 41,463,461 | $522,340,751 | +$15,664,277 | $12.65 | 179 |
| 2024 Q3 | 40,273,968 | $449,624,914 | +$10,695,609 | $11.21 | 179 |
| 2024 Q2 | 38,733,238 | $496,535,322 | +$10,201,544 | $12.82 | 182 |
| 2024 Q1 | 37,851,350 | $591,468,537 | -$4,976,804 | $15.63 | 172 |
| 2023 Q4 | 38,145,550 | $628,407,255 | +$31,651,145 | $16.48 | 174 |
| 2023 Q3 | 36,343,104 | $438,745,752 | -$11,313,309 | $12.06 | 166 |
| 2023 Q2 | 37,227,104 | $529,566,033 | -$22,316,812 | $14.24 | 159 |
| 2023 Q1 | 38,580,360 | $596,164,176 | +$63,723,924 | $15.48 | 156 |
| 2022 Q4 | 34,499,926 | $600,947,413 | +$62,491,641 | $17.44 | 165 |
| 2022 Q3 | 31,445,947 | $401,072,377 | -$34,274,712 | $12.75 | 148 |
| 2022 Q2 | 36,839,151 | $417,676,977 | -$31,197,327 | $11.35 | 137 |
| 2022 Q1 | 37,774,546 | $392,130,695 | -$17,253,058 | $10.40 | 140 |
| 2021 Q4 | 37,338,742 | $598,873,108 | +$13,548,357 | $16.05 | 129 |
| 2021 Q3 | 36,051,024 | $516,212,696 | -$1,311,166 | $14.32 | 126 |
| 2021 Q2 | 36,096,104 | $565,003,596 | -$9,221,478 | $15.66 | 122 |
| 2021 Q1 | 36,524,284 | $611,655,331 | -$28,313,721 | $16.74 | 135 |
| 2020 Q4 | 37,401,411 | $575,050,561 | -$4,694,044 | $15.38 | 134 |
| 2020 Q3 | 36,718,299 | $468,543,199 | -$11,638,357 | $12.77 | 127 |
| 2020 Q2 | 37,390,881 | $535,312,958 | +$19,443,291 | $14.32 | 133 |
| 2020 Q1 | 35,974,950 | $443,933,094 | -$8,960,245 | $12.34 | 120 |