OCTAVE SPECIALTY GROUP INC

Please refer to Note 2. Basis of Presentation and Significant Accounting Policies to the Consolidated Financial Statements, included in Part II, Item 8 in this Annual Report Form 10-K for a discussion of the impact of recent accounting pronouncements on Octave’s financial condition and results of operations.

U.S. INSURANCE BASIS FINANCIAL RESULTS

OSG's U.S. insurance subsidiaries prepare financial statements under accounting practices prescribed or permitted by its domiciliary state regulator (“SAP”) for determining and reporting the financial condition and results of operations of an insurance company. The NAIC Accounting Practices and Procedures manual (“NAIC SAP”) is adopted as a component of prescribed practices by each domiciliary state. For further information, see Note 9. Insurance Regulatory Restrictions to the Consolidated Financial Statements included in Part II, Item 8 in this Annual Report Form 10-K.

Everspan Indemnity Insurance Company

Everspan Indemnity Insurance Company’s (EIIC) statutory policyholder surplus was $128,031 at December 31, 2025, as compared to $125,202 at December 31, 2024. The increase in surplus was driven by net income at EIIC, including its subsidiaries, of $2,285 during theyear ended December 31, 2025. Each of Everspan's insurance carriers are a direct or indirect wholly-owned subsidiary of EIIC and therefore are included in EIIC's statutory policyholder surplus.

The significant differences between GAAP and SAP are that under SAP:

•Investment grade fixed maturity investments are stated at amortized cost and certain below-investment-grade fixed maturity investments are reported at the lower of amortized cost or fair value. Under GAAP, all fixed maturity investments are reported at fair value.

•Majority-owned subsidiaries are not consolidated; rather, the equity basis of accounting is utilized and the carrying values of these investments are subject to admissibility tests. The carrying values of Providence Washington Insurance Company, Greenwood Insurance Company, and Consolidated Specialty Insurance Company include a goodwill component representing the acquisition cost in excess of the related entity's statutory surplus. Goodwill is amortized over ten years under SAP. Under GAAP, the initial acquisitions of the companies were recorded as asset acquisitions, which required i) all net assets to initially be recorded at fair value and ii) the acquisition costs in excess of the fair value of net assets to be allocated to the bases of certain types of assets based on their relative fair values, if applicable. Acquired assets include intangible assets with indefinite lives. Such assets are not amortized, but their estimated useful lives are reevaluated each reporting period. No goodwill is recorded for asset acquisitions.

•Acquisition costs and ceding commissions, other than excess ceding commissions, are expensed or recognized at the time of a transaction. Under GAAP, acquisition costs and ceding commissions are deferred and recognized over the life of the related transaction.

•Unearned premiums and loss reserves are presented net of ceded amounts, while under GAAP, they are reflected gross of ceded amounts.