Ategrity Specialty Insurance Co Holdings

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

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

For the quarterly period ended September 30, 2026

OR

o 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 001-42695

ATEGRITY SPECIALTY INSURANCE COMPANY HOLDINGS

(Exact name of registrant as specified in its charter)

9 West 57th Street

33rd Floor

New York, New York 10019

(Address of principal executive offices, including zip code)

(212) 509-1600

(Registrant’s telephone number, including area code)

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

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. x Yes o 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). x Yes o 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. (Check one):

Large accelerated filero Accelerated filero Non-accelerated filer x Smaller reporting companyo Emerging growth companyx

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. o

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

As of November 4, 2026, the registrant had 47,831,484 shares of common stock outstanding.

ATEGRITY SPECIALTY INSURANCE COMPANY HOLDINGS

TABLE OF CONTENTS

Forward-looking statements

This Quarterly Report on Form 10-Q (“Quarterly Report”) contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These statements can be identified by the fact that they do not relate strictly to historical or current facts. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies and other future conditions, which are inherently subject to uncertainties, risks and changes in circumstances that are difficult to predict. You can identify forward-looking statements herein by the use of words such as “anticipates,” “estimates,” “expects,” “intends,” “plans,” “believes,” “will,” “should,” “would,” “may,” and “could” or the negative of these terms or other similar expressions, although not all forward-looking statements contain these identifying words. These forward-looking statements include, among others, statements relating to our future financial performance, our business prospects and strategy, anticipated financial position, liquidity and capital needs, loss reserves, reinsurance, our investment portfolio, share repurchases, taxes, and other similar matters. These forward-looking statements are based on management’s current expectations and assumptions about future events, which are inherently subject to uncertainties, risks, and changes in circumstances that are difficult to predict.

Our actual results may differ materially from those expressed in, or implied by, the forward-looking statements included in this Quarterly Report as a result of various factors, including, among others:

•the intense competition for business in our industry;

•the inability to obtain reinsurance coverage at reasonable prices and on terms that adequately protect us;

•the possibility that our loss reserves may be inadequate to cover our actual losses, which could have an adverse effect on our financial condition, results of operations, and cash flows;

•the inherent uncertainty of models resulting in actual losses that are materially different than our estimates;

•a decline in the financial strength rating assigned to Ategrity Specialty Insurance Company (“Ategrity Specialty”) or to Ategrity Specialty Insurance Limited (“Ategrity Limited”) adversely affecting the amount of business we write;

•our reliance on a select group of brokers;

•unexpected changes in the interpretation of our coverage or provisions;

•adverse economic factors, including recession, inflation, periods of high unemployment or lower economic activity resulting in the sale of fewer policies than expected, or an increase in frequency or severity of claims and premium defaults, or both, affecting our growth and profitability;

•the performance of our investment portfolio adversely affecting our financial results;

•the potential loss of one or more key executives or an inability to attract and retain qualified personnel adversely affecting our results of operations;

•the failure of any of the loss limitations or exclusions we employ, or change in other claims or coverage issues, having a material adverse effect on our financial condition or results of operations;

•extensive regulation adversely affecting our ability to achieve our business objectives or the failure to comply with these regulations adversely affecting our financial condition and results of operations;

•the effects of litigation having an adverse effect on our business;

•the inability to manage our growth effectively;

•the ability to pay dividends and other distributions and service our debt obligations being dependent on our ability to obtain cash dividends or other permitted payments from Ategrity Specialty;

•being forced to sell investments to meet our liquidity requirements;

•our underwriters and other associates taking excessive risks;

•the possibility that severe weather conditions and other catastrophes may result in an increase in the number and amount of claims filed against us;

•the ability of Zimmer Financial Services Group LLC (“ZFSG”) and its affiliates to exert significant influence over us and our corporate decisions;

•the failure to maintain effective internal controls in accordance with the Sarbanes-Oxley Act; and

•other risks and uncertainties discussed in “Risk Factors” in Part I, Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2025 (our “2025 Form 10-K”) and elsewhere herein.

Accordingly, you should read this Quarterly Report completely and with the understanding that our actual future results may be materially different from what we expect.

Forward-looking statements speak only as of the date they are made. Except as expressly required under federal securities laws and the rules and regulations of the SEC, we do not have any obligation, and do not undertake, to update any forward-looking statement, whether as a result of new information, future events, or otherwise. You should not place undue reliance on forward-looking statements. All forward-looking statements attributable to us are expressly qualified by these cautionary statements.