Octave Specialty Group Inc
OSG- Exchange
- NYSE
- Industry
- Surety Insurance
- SEC CIK
- 0000874501
No open-market purchases or sales by Octave Specialty Group Inc insiders were filed in the last 90 days; 147 institutions reported holding it in 13F filings for Q2 2026, worth $187.6M in total; no superinvestor holds it.
Holders of 5% or more of OSG
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Octave Specialty Group Inc, largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| BlackRock, Inc. | 13G/A | 7.60%3.54M shares | −1.10 ppfrom 8.70% | Apr 3, 20252 filings | Oct 17, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
8 Schedule 13D and 13G filings on Octave Specialty Group Inc, newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Mar 27, 202611:06 AM ET | Vanguard Group Inc | 13G/A | 0.00%0 shares | −5.75 ppfrom 5.75%Below 5% | Mar 13, 2026 | SEC |
| Nov 13, 20255:37 PM ET | Susquehanna Securities, LLCand 2 others | 13G/A | 2.20%1.02M shares | −2.90 ppfrom 5.10%Below 5% | Sep 30, 2025 | SEC |
| Oct 17, 20256:40 PM ET | BlackRock, Inc. | 13G/A | 7.60%3.54M shares | −1.10 ppfrom 8.70% | Sep 30, 2025 | SEC |
| Oct 9, 20251:48 PM ET | Dimensional Fund Advisors LP | 13G/A | 4.60%2.14M shares | –Below 5% | Sep 30, 2025 | SEC |
| Aug 14, 202510:28 AM ET | Susquehanna Securities, LLCand 1 other | 13G | 5.10%2.38M shares | New | Jun 30, 2025 | SEC |
| Apr 30, 202510:57 AM ET | Vanguard Group Inc | 13G/A | 5.75%2.66M shares | −1.02 ppfrom 6.77% | Mar 31, 2025 | SEC |
| Apr 3, 20254:24 PM ET | BlackRock, Inc. | 13G/A | 8.70%4.00M shares | – | Mar 31, 2025 | SEC |
| Jan 30, 20258:09 PM ET | Vanguard Group Inc | 13G/A | 6.77%3.22M shares | – | Dec 31, 2024 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Octave Specialty Group Inc shares.
No Form 144 notices for Octave Specialty Group Inc are on file.