Ategrity Specialty Insurance Co Holdings

We report our financial results in accordance with GAAP. However, we believe that certain non-GAAP financial measures provide investors in our common stock with additional useful information in evaluating our performance. Management believes that excluding certain items that are not indicative of core performance assists in evaluating our ability to generate earnings and to more readily compare these metrics between past and future periods. These non-GAAP financial measures may be different than similarly titled measures used by other companies.

These non-GAAP financial measures should not be considered in isolation from, or as substitutes for, financial information prepared in accordance with GAAP. There are limitations related to the use of these non-GAAP financial measures as compared to the most directly comparable GAAP financial measures.

Underwriting income

We define underwriting income as income before income taxes excluding the impact of net investment income, net realized and unrealized gains (losses) on investments, other income, interest expense, and other expenses (which include expenses related to corporate activities and expenses recorded by us in connection with the Company’s initial public offering). Underwriting income is a measure of the pre-tax profitability of our underwriting operations and allows us to evaluate our underwriting performance without regard to net investment income among other things. We use this metric as we believe it gives our management and other users of our financial information useful insight into our underlying business performance. Underwriting income should not be viewed as a substitute for income before income taxes calculated in accordance with GAAP and other companies may define underwriting income differently.

Underwriting income for the three and nine months ended September 30, 2025 and 2024 reconciles to income before income taxes as follows:

Adjusted net income attributable to stockholders

We define adjusted net income attributable to stockholders as net income attributable to stockholders excluding certain other non-operating expenses, which include expenses recorded by us in connection with the Company’s initial public offering. Adjusted net income attributable to stockholders excludes the impact of certain items that may not be indicative of underlying business trends, operating results, or future outlook, net of tax impact. We use adjusted net income attributable to stockholders as an internal performance measure in the management of our operations because we believe it gives our management and other users of our financial information useful insight into our results of operations and our underlying business performance. Adjusted net income attributable to stockholders should not be viewed as a substitute for net income attributable to stockholders calculated in accordance with GAAP, and other companies may define adjusted net income differently.

Adjusted net income attributable to stockholders for the three and nine months ended September 30, 2025 and 2024 reconciles to net income attributable to stockholders’ as follows:

(1) In the three and nine months ended September 30, 2025, other non-operating expenses includes share-based compensation expenses recorded by us related to our initial public offering.

Adjusted return on stockholders’ equity

We define adjusted return on stockholders’ equity as adjusted net income attributable to stockholders, expressed as a percentage of average beginning and ending stockholders’ equity during the period. We use adjusted return on stockholders’ equity as an internal performance measure in the management of our operations because we believe it gives our management and other users of our financial information useful insight into our results of operations and our underlying business performance. Adjusted return on stockholders’ equity should not be viewed as a substitute for return on stockholders’ equity calculated in accordance with GAAP, and other companies may define adjusted return on stockholders’ equity and adjusted net income differently.

Adjusted return on stockholders’ equity for the three and nine months ended September 30, 2025 and 2024 reconciles to return on stockholders’ equity as follows:

(1) For the three and nine months ended September 30, 2025 and 2024, net income and adjusted net income attributable to stockholder are annualized to arrive at return on stockholders’ equity and adjusted return on stockholders’ equity.

Adjusted diluted earnings per share

We define adjusted diluted earnings per share as adjusted net income attributable to stockholders divided by weighted average common shares outstanding - diluted for the period. We use adjusted diluted earnings per share as an internal performance measure in the management of our operations because we believe it gives our management and other users of our financial information useful insight into our results of operations and our underlying business performance. Adjusted diluted earnings per share should not be viewed as a substitute for diluted earnings per share calculated in accordance with GAAP, and other companies may define adjusted diluted earnings per share differently.

Adjusted diluted earnings per share for the three and nine months ended September 30, 2025 and 2024 reconciles to diluted earnings per share as follows: