Jeffrey Scott Stein - 01 Jan 2026 Form 4 Insider Report for OCTAVE SPECIALTY GROUP INC (AMBC)

Role: Director
Signature: William J. White, attorney in fact
Issuer symbol: AMBC
Transactions as of: 01 Jan 2026
Net transactions value: $0
Form type: 4
Filing time: 05 Jan 2026, 16:26:12 UTC
Previous filing: 02 Oct 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Stein Jeffrey Scott	Director	C/O OCTAVE SPECIALTY GROUP, INC., 40 WALL STREET, 55TH FLOOR, NEW YORK	William J. White, attorney in fact	05 Jan 2026	0001559518

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	OSG	Restricted Stock Units	Award	$0	+4,524	+110%	$0.000000	8,650	01 Jan 2026	Common Stock	4,524		Direct	F1, F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	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	RSU's granted on January 1, 2026 shall vest one year later on January 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.