OSG

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · derivative · entry 7

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 418,731

Underlying: Common Stock · 221,188 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: Each deferred share unit ("DSU") represents a contingent right to receive one share of common stock of the Company.

F6 · derivative.exercise_date: 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.

F6 · derivative.expiration_date: 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.

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · derivative · entry 6

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 232,787

Underlying: Common Stock · 232,816 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock.

F4 · derivative.exercise_date: Represents the aggregate amount of RSUs that vested.

F4 · derivative.expiration_date: Represents the aggregate amount of RSUs that vested.

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · derivative · entry 5

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 465,603

Underlying: Common Stock · 15,229 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock.

F4 · derivative.exercise_date: Represents the aggregate amount of RSUs that vested.

F4 · derivative.expiration_date: Represents the aggregate amount of RSUs that vested.

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · nonDerivative · entry 4

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,072,032

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · nonDerivative · entry 3

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,083,670

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The reporting person acquired shares of common stock Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · nonDerivative · entry 2

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,072,042

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-065277 · wk-form4_1791328904.xml · nonDerivative · entry 1

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,080,463

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The reporting person acquired shares of common stock Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-065275 · wk-form4_1791328854.xml · derivative · entry 4

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 138,240

Underlying: Common Stock · 52,894 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: Each deferred share unit ("DSU") represents a contingent right to receive one share of common stock of the Company.

F6 · derivative.exercise_date: 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.

F6 · derivative.expiration_date: 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.

SEC source: 0001628280-26-065275 · wk-form4_1791328854.xml · derivative · entry 3

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 64,881

Underlying: Common Stock · 55,433 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Represents the aggregate amount of RSUs that vested.

F4 · derivative.exercise_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on October 3, 2026, July 9, 2027, and July 9, 2028.

F4 · derivative.expiration_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on October 3, 2026, July 9, 2027, and July 9, 2028.

SEC source: 0001628280-26-065275 · wk-form4_1791328854.xml · nonDerivative · entry 2

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 156,326

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-065275 · wk-form4_1791328854.xml · nonDerivative · entry 1

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 158,865

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The reporting person acquired shares of common stock Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-065273 · wk-form4_1791328809.xml · derivative · entry 4

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 120,015

Underlying: Common Stock · 63,472 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: Each deferred share unit ("DSU") represents a contingent right to receive one share of common stock of the Company.

F6 · derivative.exercise_date: 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.

F6 · derivative.expiration_date: 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.

SEC source: 0001628280-26-065273 · wk-form4_1791328809.xml · derivative · entry 3

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 58,459

Underlying: Common Stock · 66,519 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the common stock of the Company's common stock.

F4 · derivative.exercise_date: Represents the aggregate amount of RSUs that vested.

F4 · derivative.expiration_date: Represents the aggregate amount of RSUs that vested.

SEC source: 0001628280-26-065273 · wk-form4_1791328809.xml · nonDerivative · entry 2

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 267,096

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-065273 · wk-form4_1791328809.xml · nonDerivative · entry 1

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 270,143

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The reporting person acquired shares of common stock Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-064968 · wk-form4_1791232356.xml · derivative · entry 1

Stein Jeffrey Scott · CIK 0001559518 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,815

Underlying: Common Stock · 8,224 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

F2 · derivative.expiration_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

SEC source: 0001628280-26-064965 · wk-form4_1791232300.xml · derivative · entry 1

PRICE MICHAEL D · CIK 0001241508 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,815

Underlying: Common Stock · 8,224 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

F2 · derivative.expiration_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

SEC source: 0001628280-26-064958 · wk-form4_1791232121.xml · derivative · entry 1

Matus Kristi Ann · CIK 0001543504 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,815

Underlying: Common Stock · 8,224 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

F2 · derivative.expiration_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

SEC source: 0001628280-26-064951 · wk-form4_1791232010.xml · derivative · entry 1

LAMMTENNANT JOAN M · CIK 0001208239 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,815

Underlying: Common Stock · 8,224 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

F2 · derivative.expiration_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

SEC source: 0001628280-26-064948 · wk-form4_1791231954.xml · derivative · entry 1

IGLESIAS LISA G · CIK 0001103172 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,815

Underlying: Common Stock · 8,224 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

F2 · derivative.expiration_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

SEC source: 0001628280-26-064945 · wk-form4_1791231905.xml · derivative · entry 1

HAFT IAN DAVID · CIK 0001573787 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 30,815

Underlying: Common Stock · 8,224 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

F2 · derivative.expiration_date: RSU's granted on October 1, 2026 shall vest one year later on October 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the reporting person.

SEC source: 0001628280-26-048011 · wk-form4_1783973141.xml · derivative · entry 3

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 480,832

Underlying: Common Stock · 39,380 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock.

F4 · derivative.exercise_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on July 9, 2026, July 9, 2027, and July 9, 2028.

F4 · derivative.expiration_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on July 9, 2026, July 9, 2027, and July 9, 2028.

SEC source: 0001628280-26-048011 · wk-form4_1783973141.xml · nonDerivative · entry 2

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,065,234

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-048011 · wk-form4_1783973141.xml · nonDerivative · entry 1

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,087,011

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: 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 restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-048005 · wk-form4_1783973075.xml · derivative · entry 3

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 132,093

Underlying: Common Stock · 11,779 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the common stock of the Company's common stock.

F4 · derivative.exercise_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on July 9, 2026, July 9, 2027, and July 9, 2028.

F4 · derivative.expiration_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on July 9, 2026, July 9, 2027, and July 9, 2028.

SEC source: 0001628280-26-048005 · wk-form4_1783973075.xml · nonDerivative · entry 2

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 156,326

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-048005 · wk-form4_1783973075.xml · nonDerivative · entry 1

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 160,961

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The reporting person acquired shares of common stock Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-047997 · wk-form4_1783972941.xml · derivative · entry 3

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 124,978

Underlying: Common Stock · 13,206 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the common stock of the Company's common stock.

F4 · derivative.exercise_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on July 9, 2026, July 9, 2027, and July 9, 2028.

F4 · derivative.expiration_date: The RSUs vested pursuant to the first of three equal annual installments under the reporting person's 2025 Long Term Incentive Plan award, which vests in equal installments on July 9, 2026, July 9, 2027, and July 9, 2028.

SEC source: 0001628280-26-047997 · wk-form4_1783972941.xml · nonDerivative · entry 2

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 267,096

F2 · balance_after: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-047997 · wk-form4_1783972941.xml · nonDerivative · entry 1

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 273,837

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · price: The reporting person acquired shares of common stock Octave Specialty Group, Inc. (the "Company") upon the vesting and settlement of a portion of the reporting person's restricted stock unit ("RSU") awards as part of their 2025 Long Term Incentive Plan.

SEC source: 0001628280-26-047531 · wk-form4_1783458211.xml · derivative · entry 1

Stein Jeffrey Scott · CIK 0001559518 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,591

Underlying: Common Stock · 6,500 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

F2 · derivative.expiration_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

SEC source: 0001628280-26-047527 · wk-form4_1783458176.xml · derivative · entry 1

PRICE MICHAEL D · CIK 0001241508 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,591

Underlying: Common Stock · 6,500 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

F2 · derivative.expiration_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

SEC source: 0001628280-26-047525 · wk-form4_1783458141.xml · derivative · entry 1

Matus Kristi Ann · CIK 0001543504 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,591

Underlying: Common Stock · 6,500 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

F2 · derivative.expiration_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

SEC source: 0001628280-26-047523 · wk-form4_1783458107.xml · derivative · entry 1

LAMMTENNANT JOAN M · CIK 0001208239 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,591

Underlying: Common Stock · 6,500 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

F2 · derivative.expiration_date: RSUs granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company or upon a "change of control" of the Company.

SEC source: 0001628280-26-047521 · wk-form4_1783458068.xml · derivative · entry 1

IGLESIAS LISA G · CIK 0001103172 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,591

Underlying: Common Stock · 6,500 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, or upon a "change of control" of the Company.

F2 · derivative.expiration_date: RSU's granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, or upon a "change of control" of the Company.

SEC source: 0001628280-26-047518 · wk-form4_1783458014.xml · derivative · entry 1

HAFT IAN DAVID · CIK 0001573787 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 22,591

Underlying: Common Stock · 6,500 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company.

F2 · derivative.expiration_date: RSU's granted on July 1, 2026 shall vest one year later on July 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company.

SEC source: 0001628280-26-023253 · wk-form4_1775162349.xml · derivative · entry 1

Stein Jeffrey Scott · CIK 0001559518 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,091

Underlying: Common Stock · 7,441 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

F2 · derivative.expiration_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

SEC source: 0001628280-26-023249 · wk-form4_1775162309.xml · derivative · entry 1

HAFT IAN DAVID · CIK 0001573787 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,091

Underlying: Common Stock · 7,441 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

F2 · derivative.expiration_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

SEC source: 0001628280-26-023247 · wk-form4_1775162278.xml · derivative · entry 1

IGLESIAS LISA G · CIK 0001103172 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,091

Underlying: Common Stock · 7,441 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

F2 · derivative.expiration_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

SEC source: 0001628280-26-023240 · wk-form4_1775162240.xml · derivative · entry 1

LAMMTENNANT JOAN M · CIK 0001208239 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,091

Underlying: Common Stock · 7,441 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

F2 · derivative.expiration_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

SEC source: 0001628280-26-023236 · wk-form4_1775162195.xml · derivative · entry 1

Matus Kristi Ann · CIK 0001543504 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,091

Underlying: Common Stock · 7,441 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

F2 · derivative.expiration_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

SEC source: 0001628280-26-023230 · wk-form4_1775162141.xml · derivative · entry 1

PRICE MICHAEL D · CIK 0001241508 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 16,091

Underlying: Common Stock · 7,441 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

F2 · derivative.expiration_date: RSU's granted on April 1, 2026 shall vest one year later on April 1, 2027. RSUs that have become vested shall settle and convert into shares of common stock upon the earlier of the vesting date or the date that the reporting person resigns from, or otherwise ceases to be a member of, the Board of Directors of the Company, unless otherwise deferred upon the election of the Reporting person.

SEC source: 0001628280-26-021062 · wk-form4_1774472107.xml · derivative · entry 1

LeBlanc Claude · CIK 0001380820 · Director · Chief Executive Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 520,212

Underlying: Common Stock · 99,375 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: On March 23, 2026 the reporting person received a grant of 99,375 RSUs as part of his 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

F2 · derivative.expiration_date: On March 23, 2026 the reporting person received a grant of 99,375 RSUs as part of his 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

SEC source: 0001628280-26-021064 · wk-form4_1774472574.xml · derivative · entry 4

Ahn Cristina E. · CIK 0001977360 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 9,718

Underlying: Common Stock · 8,067 shares

Expires not disclosed

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock.

F4 · price: On March 23, 2026 the reporting person received a grant of 8,067 restricted stock units ("RSUs") as part of her 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

F4 · derivative.exercise_date: On March 23, 2026 the reporting person received a grant of 8,067 restricted stock units ("RSUs") as part of her 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

F4 · derivative.expiration_date: On March 23, 2026 the reporting person received a grant of 8,067 restricted stock units ("RSUs") as part of her 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

SEC source: 0001628280-26-021059 · wk-form4_1774472067.xml · derivative · entry 1

Smith R Sharon · CIK 0001707461 · Exec VP & Group COO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 120,314

Underlying: Common Stock · 24,375 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: On March 23, 2026 the reporting person received a grant of 24,375 RSUs as part of her 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

F2 · derivative.expiration_date: On March 23, 2026 the reporting person received a grant of 24,375 RSUs as part of her 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

SEC source: 0001628280-26-021057 · wk-form4_1774472010.xml · derivative · entry 1

Trick David · CIK 0001480597 · Exec VP, CFO & Treasurer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 138,184

Underlying: Common Stock · 26,250 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: On March 23, 2026 the reporting person received a grant of 26,250 RSUs as part of his 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

F2 · derivative.expiration_date: On March 23, 2026 the reporting person received a grant of 26,250 RSUs as part of his 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

SEC source: 0001628280-26-021055 · wk-form4_1774471890.xml · derivative · entry 1

METZ LAWRENCE F. · CIK 0001496992 · *See Remarks for full title

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 28,246

Underlying: Common Stock, par value $0.01 per share · 28,246 shares

Expires not disclosed

F1 · derivative.exercise_price: Each restricted stock unit ("RSU") represents a contingent right to receive one share of the common stock of Octave Specialty Group, Inc. (the "Company").

F2 · derivative.exercise_date: On March 23, 2026 the reporting person received a grant of 28,246 RSUs as part of his 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

F2 · derivative.expiration_date: On March 23, 2026 the reporting person received a grant of 28,246 RSUs as part of his 2026 Long Term Incentive Plan award. The RSUs will vest in three equal annual installments commencing March 23, 2027, March 23, 2028, and March 23, 2029.

SEC source: 0001628280-26-021064 · wk-form4_1774472574.xml · derivative · entry 3

Ahn Cristina E. · CIK 0001977360 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,651

Underlying: Common Stock · 835 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F3 · derivative.exercise_price: Each RSU represents a contingent right to receive one share of the Company's common stock.

F1 · shares: Represents the aggregate amount of restricted stock units ("RSUs") that were converted into shares of common stock of Octave Specialty Group, Inc. (the "Company") upon settlement of a portion of the reporting person's 2025 Long Term Incentive Plan award.

F1 · price: Represents the aggregate amount of restricted stock units ("RSUs") that were converted into shares of common stock of Octave Specialty Group, Inc. (the "Company") upon settlement of a portion of the reporting person's 2025 Long Term Incentive Plan award.

F3 · derivative.exercise_date: Each RSU represents a contingent right to receive one share of the Company's common stock.

F3 · derivative.expiration_date: Each RSU represents a contingent right to receive one share of the Company's common stock.

SEC source: 0001628280-26-021064 · wk-form4_1774472574.xml · nonDerivative · entry 2

Ahn Cristina E. · CIK 0001977360 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 632

F2 · shares: Represents the amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.

SEC source: 0001628280-26-021064 · wk-form4_1774472574.xml · nonDerivative · entry 1

Ahn Cristina E. · CIK 0001977360 · Chief Accounting Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 835

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · shares: Represents the aggregate amount of restricted stock units ("RSUs") that were converted into shares of common stock of Octave Specialty Group, Inc. (the "Company") upon settlement of a portion of the reporting person's 2025 Long Term Incentive Plan award.

F1 · price: Represents the aggregate amount of restricted stock units ("RSUs") that were converted into shares of common stock of Octave Specialty Group, Inc. (the "Company") upon settlement of a portion of the reporting person's 2025 Long Term Incentive Plan award.