INTERNATIONAL BANCSHARES CORP

INTEREST RATE SENSITIVITY

(Dollars in Thousands)

The detailed inventory of statement of condition items contained in gap reports is the starting point of income simulation analysis. Income simulation analysis also focuses on the variability of net interest income and net income, but without the limitations of gap analysis. In particular, the fundamental, but often unstated, assumption of the gap approach that every statement of condition item that can re-price will do so to the full extent of any movement in market interest rates is taken into consideration in income simulation analysis.

Accordingly, income simulation analysis captures not only the potential of assets and liabilities to mature or re-price, but also the probability that they will do so. Moreover, income simulation analysis focuses on the relative sensitivities of these balance sheet items and projects their behavior over an extended period of time in a motion picture rather than snapshot fashion. Finally, income simulation analysis permits management to assess the probable effects on balance sheet items not only of changes in market interest rates, but also of proposed strategies for responding to such

changes. We and many other institutions rely primarily upon income simulation analysis in measuring and managing exposure to interest rate risk.

We have established guidelines for acceptable volatility of projected net interest income on the income simulation analysis and the guidelines are reviewed at least annually. As of December 31, 2025, in decreasing rate scenarios of -100, -200, -300 and -400 basis points and in rising rate scenarios of +100, +200, +300 and +400 basis points, the guidelines established by management require that the net interest income not vary by more than minus 15%, 15%, 15%, and 20%, respectively, for the first 12-month period projected. At December 31, 2025, the most recent income simulations show that a rate shift of -100, -200, -300, -400, +100, +200, +300 and +400 basis points in interest rates up will vary projected net interest income for the coming 12-month period by -2.71%, -4.88%, -6.55%, -7.75% +3.56%, +7.31%, +11.01% and +14.67%, respectively. The basis point shift in interest rates is a hypothetical rate scenario used to calibrate risk and does not necessarily represent management’s current view of future market developments. We believe that we are properly positioned for a potential interest rate increase or decrease.

All the measurements of risk described above are made based upon our business mix and interest rate exposures at the particular point in time. The exposure changes continuously as a result of our ongoing business and our risk management initiatives. While management believes these measures provide a meaningful representation of our interest rate sensitivity, they do not necessarily take into account all business developments that have an effect on net income, such as changes in credit quality or the size and composition of the statement of condition.

Our principal sources of liquidity and funding dividends from subsidiaries and borrowed funds, with such funds being used to finance our cash flow requirements. We closely monitor the dividend restrictions and availability from our Subsidiary Banks as disclosed in Note 18 of the Notes to Consolidated Financial Statements. At December 31, 2025, the aggregate amount legally available to be distributed to us from our Subsidiary Banks as dividends was approximately $1,644,000,000, assuming that each Subsidiary Bank continues to be classified as “well capitalized” under the applicable regulations in effect at December 31, 2024. The restricted capital (capital and surplus) of our Subsidiary Banks was approximately $1,506,627,000 as of December 31, 2025. The undivided profits of our Subsidiary Banks were approximately $2,254,243,000 as of December 31, 2025.

At December 31, 2025, we had outstanding $10,332,000 in other borrowed funds and $108,868,000 in junior subordinated deferrable interest debentures. In addition to borrowed funds and dividends, we have a number of other available alternatives to finance the growth of our Subsidiary Banks as well as future growth and expansion.