Accelerant Holdings

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2025

or

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from_______to_______

Commission File Number 001-42765

ACCELERANT HOLDINGS

(Exact Name of Registrant as Specified in Its Charter)

Accelerant Holdingsc/o Accelerant Re (Cayman) Ltd.Unit 106, Windward 3, Regatta Office Park,West Bay Road, Grand Cayman, KY1-11081 (345) 743-4611(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. ☐ Yes ☒No

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act. ☐ Yes ☒No

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. ☒ Yes ☐ No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). ☒Yes ☐ No

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and "emerging growth company" in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☒

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements.☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240.10D-1(b).☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). ☐ Yes☒ No

As of June 30, 2025, the registrant wasnot a public company and therefore cannot calculate the aggregate market value of its voting and non-voting common equity held by non-affiliates as of such date.

As of March 12, 2026, there were 222,160,004 of the registrant’s common shares outstanding, comprised of 116,757,858 Class A common shares, $0.0000011951862 par value per share and 105,402,146 Class B common shares, $0.0000011951862 par value per share.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the Registrant’s definitive Proxy Statement for its 2026 Annual General Meeting of Shareholders are incorporated by reference into Part III of this Annual Report on Form 10-K where indicated. The Proxy Statement will be filed no later than 120 days after the Registrant’s fiscal year ended December 31, 2025.

Cautionary Note Regarding Forward-Looking Statements

This Annual Report on Form 10-K contains forward-looking statements. You can generally identify forward-looking statements by our use of forward-looking terminology such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “projection,” “seek,” “should,” “will” or “would,” or the negative thereof or other variations thereon or comparable terminology.

In particular, statements about the markets in which we operate, including growth of our various markets, and our expectations, beliefs, plans, strategies, objectives, prospects, assumptions, or future events or performance contained in this Annual Report on Form 10-K under the heading “Management’s Discussion and Analysis of Financial Condition and Results of Operations” are forward-looking statements.

We have based these forward-looking statements on our current expectations, assumptions, estimates and projections. While we believe these expectations, assumptions, estimates and projections are reasonable, such forward-looking statements are only predictions and involve known and unknown risks and uncertainties, many of which are beyond our control. These and other important factors, including those discussed in this Annual Report on Form 10-K under the headings "Risk Factors, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and "Quantitative and Qualitative Disclosure About Market Risk" may cause our actual results, performance or achievements to differ materially from any future results, performance or achievements expressed or implied by these forward-looking statements, or could affect our share price.

Forward-looking statements contained in this Annual Report on Form 10-K include, but are not limited to, statements about:

•our Risk Exchange’s prospects, its potential for expansion to new Members, Risk Capital Partners (including third-party insurers and reinsurers) and offerings beyond the specialty insurance market, as well as the future prospects of our overall business;

•our ability to grow our business profitably;

•our financial strength;

•the number of Members and Risk Capital Partners that we expect to retain and our membership growth prospects;

•our ability to continue enhancing our technology-based solutions and gain internal efficiencies and effective controls that promote the utility of the analytics we provide to Members and Risk Capital Partners;

•our ability to leverage our information systems to enhance the benefits available to our Members through our Risk Exchange;

•our ability to continue to attract Risk Capital Partners;

•the performance of our Members and Risk Capital Partners;

•our ability to accurately assess and manage the underwriting risk we retain and the impacts of sliding scale commissions on the underwriting risk we do not retain;

•the competitive environment in the specialty insurance industry;

•changes in government laws and regulations, including insurance regulatory laws, and how the enforcement thereof may affect our business;

•our expectations regarding our projected growth;

•the increased expenses associated with being a public company;

•whether we will be considered a passive foreign investment company for US tax purposes;

•the additional regulatory, legal and operational risks that may arise in connection with our expansion into new geographies and how such risks might materially affect our business, results of operations, financial condition, and prospects; and

•other factors detailed in Item 1A. "Risk Factors" below.

Given the risks and uncertainties set forth in this Annual Report on Form 10-K, you are cautioned not to place undue reliance on such forward-looking statements. The forward-looking statements contained in this Annual Report on Form 10-K are not guarantees of future performance and our actual results of operations, financial condition, and liquidity, and the development of the industry in which we operate, may differ materially from the forward-looking statements contained in this Annual Report on Form 10-K. In addition, even if our results of operations, financial condition and liquidity, and events in the industry in which we operate, are consistent with the forward-looking statements contained in this Annual Report on Form 10-K, they may not be predictive of results or developments in future periods.

Any forward-looking statement that we make in this Annual Report on Form 10-K speaks only as of the date of such statement. Except as required by law, we do not undertake any obligation to update or revise, or to publicly announce any update or revision to, any of the forward-looking statements, whether as a result of new information, future events or otherwise, after the date of this Annual Report on Form 10-K.

Glossary

As used in this Annual Report on Form 10-K, unless the context indicates or otherwise requires, the following terms have the following meanings:

•Accelerant Direct Written Premium: Expressed as a percentage of Exchange Written Premium, the GWP written directly by Accelerant Underwriting companies, the majority of which we cede to Risk Capital Partners through our reinsurance arrangements.

•Accelerant GWP: The total GWP written by Accelerant Underwriting companies (both written by our insurance company and assumed as a reinsurer), the majority of which we cede to Risk Capital Partners through our reinsurance arrangements.

•Accelerant Holdings LP Distribution: The distribution of all of our existing common shares to holders of limited partnership interests of Accelerant Holdings LP in proportion to the economic interests represented by those limited partnership interests that occurred immediately prior to the consummation of our initial public offering in July 2025. The then-existing common shares were subsequently redesignated as 75,988,500 Class A common shares and 90,196,594 Class B common shares.

•Accelerant Re: Accelerant Re (Cayman) Ltd and Accelerant Re I.I.

•Accelerant-Retained Exchange Premium: Expressed as a percentage, as Accelerant GWP net of ceded written premium for the trailing twelve-month period, divided by total Exchange Written Premium for the trailing twelve-month period.

•Accelerant Underwriting: Accelerant’s owned insurance companies and reinsurance companies, and all revenue and expenses associated with them.

•AI: Artificial Intelligence.

•DAC: Deferred acquisition costs.

•Exchange Written Premium: The total gross written premium written through the Risk Exchange, including both gross written premiums of Accelerant Underwriting companies and Risk Exchange Insurers.

•Exchange Written Premium Growth Rate: The percentage increase in Exchange Written Premium in the current period compared to Exchange Written Premium from the comparable period in the prior year period.

•ESG: Environmental, Social, and Governance.

•FCA: Financial Conduct Authority.

•Flywheel Re: Collectively, Flywheel Re Ltd. SPC and Flywheel Holdings Ltd. SPC, a Cayman Islands holding company that indirectly owns Flywheel Re Ltd. SPC (unconsolidated reinsurance sidecar entities), sponsored by Accelerant and through which institutional investors are offered specialty insurance risk and returns that are relatively uncorrelated with broader financial markets.

•GAAP: Accounting Principles Generally Accepted in the US.

•Gross Loss Ratio: Gross incurred losses and loss adjustment expense divided by gross earned premium (expressed as a percentage). Gross loss ratio excludes the impact of premium and loss and loss adjustment expense ceded to reinsurers. Gross loss ratio represents the percentage of gross premium earned during the period that will be required to pay current and future claims, based on management’s best estimates.

•GWP: Gross written premium, representing the total amount of premium contracted for all policies issued in a given period.

•Independent Members: Members in which Accelerant does not own an interest.

•Independent Premium: The gross premium written by Independent Members and placed through our Risk Exchange.

•LAE: Loss adjustment expense.

•Members: Specialized underwriters, including MGAs, MGUs, and program managers (terms we use interchangeably) that underwrite insurance premiums on behalf of Risk Capital Partners through our Risk Exchange.

•MGA: Managing general agent; a third-party agent that receives delegated underwriting authority from a Primary Insurance Company to write insurance risk on its behalf. The term “MGA” refers generically to agents receiving this delegation of underwriting authority, including MGUs, MGAs, and/or program managers and any Member or other entity in relation to which the term “MGA” is used and may not fall within the regulatory definition of a “managing general agent” in the jurisdictions in which it operates.

•MGU: Managing general underwriter; a third-party agent that receives delegated underwriting authority from a Primary Insurance Company to write insurance risk on its behalf.

•Mission Europe: Mission Holdings Europe Ltd., one of our subsidiaries.

•Mission Members: Specialty underwriters that operate and develop through Mission Underwriters and in which we have an equity ownership interest.

•Mission Underwriters: Mission Underwriters provides specialty underwriters with the working capital, operational support, and balance sheet capacity necessary to operate their own MGAs, in which the specialty underwriters have a majority ownership interest. These MGAs are Members of the Risk Exchange. Mission Underwriters operates in the US, UK and EU through Mission US and Mission Europe.

•Mission US: Mission Underwriting Holdings, LLC.

•NAIC: National Association of Insurance Commissioners.

•Net Promoter Score: A widely used customer-experience metric that is meant to capture overall customer loyalty and satisfaction.

•Net Revenue Retention: Expressed as a percentage, the current period’s Exchange Written Premium of Members that were actively writing Exchange Written Premium in the prior period divided by these same Members’ prior-period Exchange Written Premium. This measure demonstrates an aggregate measure of the net growth of Exchange Written Premium from Members.

•Owned Members: Members in which Accelerant either has a minority equity ownership interest or controlling equity interest.

•Owned Premium: The premium produced by Mission Members and Owned Members, who receive commissions for sourcing and underwriting business.

•P&C: Property and Casualty insurance.

•PRA: Prudential Regulation Authority.

•Primary Insurance Company: Licensed carriers who write business and thus are responsible for insurance policy forms, rate filings, etc. Primary Insurance Companies may reinsure a portion of the risk they have written to third-party reinsurers.

•Reinsurer: An insurance company that insures risk written by another insurance company. Reinsurers generally are not required to be licensed directly in a given jurisdiction to provide such reinsurance coverage; however, absent any such license, reinsurers are limited only to writing such risk in a secondary reinsurance capacity and not in a primary direct capacity.

•Risk Capital Partners: Third-party insurance companies, reinsurers or institutional investors that provide capacity through the Risk Exchange, directly or indirectly.

•Risk Exchange: The Accelerant technology, data ingestion, and agency operations that serve the needs of our Members and Risk Capital Partners.

•Risk Exchange Insurer: Third-party Primary Insurance Company deploying underwriting capacity directly through our Risk Exchange.

•SAP: Statutory Accounting Principles.

•SME: Small-to-medium-sized enterprise.

•Third-Party Direct Written Premium: GWP written directly with Risk Exchange Insurers.

•TPA: Third-party administrator, providing claims handling and other operational functions related to administration of insurance policies.

•US-UK Tax Treaty: The Convention between the Government of the United States of America and the Government of the United Kingdom of Great Britain and Northern Ireland for the Avoidance of Double Taxation and the Prevention of Fiscal Evasion with Respect to Taxes on Income and on Capital Gains, signed July 24, 2001.