# EDGAR Filing Document

**Accession Number:** 0001480597
**File Stem:** 0001628280-26-015346
**Filing Date:** 2026-3
**Character Count:** 7193
**Document Hash:** 47e45497be6e4dafdf89031a981f3b0f
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001628280-26-015346.hdr.sgml**: 20260305

**ACCESSION NUMBER**: 0001628280-26-015346

**CONFORMED SUBMISSION TYPE**: 4

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260303

**FILED AS OF DATE**: 20260305

**DATE AS OF CHANGE**: 20260305

**REPORTING-OWNER**: 

**OWNER DATA:**
- **COMPANY CONFORMED NAME:** Trick David
- **CENTRAL INDEX KEY:** 0001480597

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-10777
- **FILM NUMBER:** 26727353

**MAIL ADDRESS:**
- **STREET 1:** OCTAVE SPECIALTY GROUP, INC.
- **STREET 2:** 40 WALL STREET,  55TH  FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10005
**ISSUER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** OCTAVE SPECIALTY GROUP INC
- **CENTRAL INDEX KEY:** 0000874501
- **STANDARD INDUSTRIAL CLASSIFICATION:** SURETY INSURANCE [6351]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 133621676
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**BUSINESS ADDRESS:**
- **STREET 1:** 40 WALL STREET
- **STREET 2:** 55TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10005
- **BUSINESS PHONE:** 2126587470

**MAIL ADDRESS:**
- **STREET 1:** 40 WALL STREET
- **STREET 2:** 55TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10005

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** AMBAC FINANCIAL GROUP INC
- **DATE OF NAME CHANGE:** 19980121

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** AMBAC INC /DE/
- **DATE OF NAME CHANGE:** 19930328

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM 4

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

[ ] Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Trick David<br><sub>(Last) (First) (Middle)</sub><br>C/O OCTAVE SPECIALTY GROUP, INC.<br>40 WALL STREET, 55TH FLOOR<br><sub>(Street)</sub><br>NEW YORK, NY 10005<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-03-03 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[ ] Director [ ] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_Exec VP, CFO & Treasurer_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>OCTAVE SPECIALTY GROUP INC [ OSG ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Common Stock | 2026-03-03 |  | M |  | 1715<sup>(1)</sup> | A | $0 | 262346 | D |  |
| Common Stock | 2026-03-03 |  | F |  | 1715<sup>(2)</sup> | D | $5.60 | 260631 | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Restricted Stock Units | <sup>(3)</sup> | 2026-03-03 |  | M |  |  | 11505 | <sup>(4)</sup> | <sup>(4)</sup> | Common Stock | 11505 | $0 | 111934 | D |  |
| Deferred Share Units | <sup>(5)</sup> | 2026-03-03 |  | M |  |  | 9790 | <sup>(6)</sup> | <sup>(6)</sup> | Common Stock | 9790 | $0 | 36510 | D |  |

---

### Footnotes:

(1) The reporting person acquired shares of common stock of Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's 2023 and 2024 restrictive stock unit ("RSU") awards.

(2) Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

(3) Each RSU represents a contingent right to receive one share of the Company's common stock.

(4) Represents the aggregate amount of RSUs that vested.

(5) Each deferred share unit ("DSU") represents a contingent right to receive one share of common stock of the Company.

(6) Represents the aggregate amount of RSUs that were converted into an equivalent number of DSUs pursuant to the Company's Executive Stock Deferral Plan, which was designed to enable participants to elect to defer the settlement and income taxation of RSU and Performance Stock Unit awards in accordance with Section 409A of the Internal Revenue Code of 1986, as amended.

**Signature:** William White, attorney-in-fact  
**Date:** 2026-03-05

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**