Stellar Bancorp, Inc. Reports First Quarter 2026 Results

Stellar Bancorp, Inc. (the "Company" or "Stellar") (NYSE:STEL) today reported net income of $27.0 million, or diluted earnings per share of $0.53, for the first quarter of 2026, compared to net income of $26.1 million, or diluted earnings per share of $0.51, for the fourth quarter of 2025.

"We are pleased to announce Stellar Bancorp's first quarter results, building on the momentum that began in the second half of last year," said Robert R. Franklin, Jr., Chief Executive Officer of Stellar Bancorp, Inc. "During the quarter, we grew our loan portfolio and expanded our net interest margin, driving improved core earnings for our shareholders. These results underscore the strength of our franchise and provide a strong foundation as we move forward with our proposed combination with Prosperity Bancshares."

"We have received the required regulatory approvals and have scheduled a special meeting of shareholders for May 27, 2026 to consider the proposed transaction," Franklin added. "Integration planning and consolidation discussions are progressing, and we believe the combination positions us to create a Texas banking platform with scale, enhanced capabilities and long‑term value. Our markets remain resilient, and we are optimistic about the opportunities ahead," Franklin concluded.

Financial Highlights

• Loan Growth: During the first quarter, loans held for investment increased $287.4 million, representing linked-quarter growth of 3.94%, or 16.0% annualized.
• Strong Net Interest Income and Margin: Net interest income was $105.9 million for the first quarter of 2026 up from $103.4 million for the fourth quarter of 2025. The tax equivalent net interest margin was 4.24% for the first quarter of 2026 compared to 4.21% for the fourth quarter of 2025. The tax equivalent net interest margin, excluding Purchase Accounting Adjustments ("PAA"), was 4.10%⁽¹⁾ for the first quarter of 2026 compared to 4.06%⁽¹⁾ for the fourth quarter of 2025.
• Earnings Growth: Net income for the first quarter of 2026 was $27.0 million, or diluted earnings per share of $0.53, which is up from $26.1 million, or diluted earnings per share of $0.51, for the fourth quarter of 2025. Excluding acquisition and merger-related expenses, adjusted net income was $29.6 million⁽¹⁾, or diluted earnings per share of $0.58, for the first quarter of 2026.
• Paydown of Subordinated Notes: On April 1, 2026, the Company redeemed the remaining $30 million of its Fixed-to-Floating Rate Subordinated Notes outstanding as of March 31, 2026.

Merger Agreement with Prosperity Bancshares, Inc.

On January 27, 2026, the Company entered into an Agreement and Plan of Merger (the "Merger Agreement") with Prosperity Bancshares, Inc., a Texas corporation ("Prosperity"). The Merger Agreement provides that, upon the terms and subject to the conditions set forth therein, the Company will merge with and into Prosperity (the "Merger"), with Prosperity continuing as the surviving corporation in the Merger. Immediately following the Merger, Stellar Bank will merge with and into Prosperity's wholly owned banking subsidiary, Prosperity Bank (the "Bank Merger"). Prosperity Bank will continue as the surviving bank in the Bank Merger. Upon the terms and subject to the conditions set forth in the Merger Agreement, at the effective time of the Merger (the "Effective Time"), each share of common stock, par value $0.01 per share, of the Company ("Stellar Common Stock") outstanding immediately prior to the Effective Time, other than certain shares held by Prosperity or the Company and shares held by a holder of Stellar Common Stock who has properly exercised applicable dissenters' rights in respect of such share, will be converted into the right to receive (i) 0.3803 shares of common stock, par value $1.00 per share, of Prosperity and (ii) an amount in cash equal to $11.36. On April 22, 2026, the Company and Prosperity announced the receipt of all regulatory approvals necessary to complete the merger. The closing of the Merger is expected to occur on or about July 1, 2026, subject to receipt of approval of the Company's shareholders and satisfaction of customary closing conditions.

First Quarter 2026 Results

Net interest income in the first quarter of 2026 increased $2.5 million, or 2.5%, to $105.9 million from $103.4 million for the fourth quarter of 2025. The net interest margin on a tax equivalent basis increased to 4.24% for the first quarter of 2026 from 4.21% for the fourth quarter of 2025. The increase in net interest income from the prior quarter was primarily due to the increase in average securities, as a result of short-term investments made to support public funds seasonality during the quarter, and the yield on securities. Net interest income for the first quarter of 2026 benefited from $3.6 million of income from PAA compared to $3.8 million in the fourth quarter of 2025. Excluding PAA, net interest income (tax equivalent) for the first quarter of 2026 would have been $102.5 million⁽¹⁾ and the tax equivalent net interest margin would have been 4.10%⁽¹⁾.

Noninterest income for the first quarter of 2026 was $5.1 million, a decrease of $398 thousand, or 7.2%, compared to $5.5 million for the fourth quarter of 2025. Noninterest income decreased in the first quarter of 2026 compared to the fourth quarter of 2025 primarily due to a death benefit on bank-owned life insurance received during the fourth quarter of 2025.

Noninterest expense for the first quarter of 2026 increased $3.0 million, or 4.2%, to $75.2 million compared to $72.2 million for the fourth quarter of 2025. The increase in noninterest expense during the first quarter of 2026 compared to the fourth quarter of 2025 was primarily due to acquisition and merger-related expenses of $3.3 million related to the pending Merger with Prosperity.

The efficiency ratio was 63.27%⁽¹⁾ for the first quarter of 2026 compared to 61.64%⁽¹⁾ for the fourth quarter of 2025. When adjusted for acquisition and merger-related expenses, the efficiency ratio for the first quarter of 2026 was 60.29%⁽¹⁾. Annualized returns on average assets, average equity and average tangible equity were 0.98%, 6.51% and 11.23%⁽¹⁾ for the first quarter of 2026, respectively, compared to 0.97%, 6.23% and 10.90%⁽¹⁾ for the fourth quarter of 2025, respectively. When adjusted for acquisition and merger-related expenses, annualized returns on average assets, average equity and average tangible equity were 1.08%⁽¹⁾, 7.14%⁽¹⁾ and 12.18%⁽¹⁾ for the first quarter of 2026, respectively.

Financial Condition

Total assets at March 31, 2026 were $10.89 billion, an increase of $82.8 million compared to $10.81 billion at December 31, 2025. The increase in total assets was largely due to an increase in loans and interest-bearing deposits at other financial institutions partially offset by a decrease in securities.

Total loans at March 31, 2026 increased $287.4 million to $7.59 billion compared to $7.30 billion at December 31, 2025. At March 31, 2026, the remaining balance of the PAA on loans was $50.7 million.

Total deposits at March 31, 2026 decreased $39.5 million to $8.98 billion compared to $9.02 billion at December 31, 2025 primarily due to the decrease in noninterest-bearing deposits.

Asset Quality

Nonperforming assets totaled $70.1 million, or 0.64% of total assets, at March 31, 2026, compared to $60.0 million, or 0.56% of total assets, at December 31, 2025. The allowance for credit losses on loans as a percentage of total loans was 1.13% at March 31, 2026 compared to 1.15% at December 31, 2025.

The provision for credit losses was $2.5 million for the first quarter of 2026 compared to $5.1 million for the fourth quarter of 2025. Net charge-offs for the first quarter of 2026 were $1.4 million, or 0.07% (annualized) of average loans, compared to net charge-offs of $71 thousand for the fourth quarter of 2025.

GAAP Reconciliation of Non-GAAP Financial Measures

Stellar's management uses certain non-GAAP financial measures to evaluate its performance. Please refer to the GAAP Reconciliation and

Management's Explanation of Non-GAAP Financial Measures on pages 11 and 12 of this earnings release for a reconciliation of these non-GAAP financial measures.

About Stellar Bancorp, Inc.

Stellar Bancorp, Inc. is a bank holding company headquartered in Houston, Texas. Stellar's principal banking subsidiary, Stellar Bank, provides a diversified range of commercial banking services primarily to small- to medium-sized businesses and individual customers across Houston, Dallas, Beaumont and surrounding communities in Texas.

Forward-Looking Statements

This press release contains statements regarding the proposed transaction between Prosperity and Stellar; future financial and operating results; benefits and synergies of the proposed transaction; future opportunities for Prosperity; the issuance of common stock of Prosperity contemplated by the Merger Agreement; the expected timing of the closing of the proposed transaction contemplated by the Merger Agreement; the ability of the parties to complete the proposed transaction considering the various closing conditions and any other statements about future expectations that constitute forward-looking statements within the meaning of the federal securities laws, including the meaning of the Private Securities Litigation Reform Act of 1995, as amended, Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended. From time to time, oral or written forward-looking statements may also be included in other information released to the public. Such forward-looking statements are typically, but not exclusively, identified by the use in the statements of words or phrases such as "aim," "anticipate," "believe," "estimate," "expect," "goal," "guidance," "intend," "is anticipated," "is expected," "is intended," "objective," "plan," "projected," "projection," "will affect," "will be," "will continue," "will decrease," "will grow," "will impact," "will increase," "will incur," "will reduce," "will remain," "will result," "would be," variations of such words or phrases (including where the word "could," "may," or "would" is used rather than the word "will" in a phrase) and similar words and phrases indicating that the statement addresses some future result, occurrence, plan or objective . Forward-looking statements include all statements other than statements of historical fact, including forecasts or trends, and are based on current expectations, assumptions, estimates, and projections about Prosperity, Stellar and their respective subsidiaries or related to the proposed transaction between Prosperity and Stellar and are subject to significant risks and uncertainties that could cause actual results to differ materially from the results expressed in such statements.

These forward-looking statements may include information about Prosperity's and Stellar's possible or assumed future economic performance or future results of operations, including future revenues, income, expenses, provision for loan losses, provision for taxes, effective tax rate, earnings per share and cash flows and Prosperity's and Stellar's future capital expenditures and dividends, future financial condition and changes therein, including changes in Prosperity's and Stellar's loan portfolio and allowance for loan losses, future capital structure or changes therein, as well as the plans and objectives of management for Prosperity's and Stellar's future operations, future or proposed acquisitions, the future or expected effect of acquisitions on Prosperity's and Stellar's operations, results of operations, financial condition, and future economic performance, statements about the anticipated benefits of the proposed transaction, and statements about the assumptions underlying any such statement.

These forward-looking statements are not guarantees of future performance and are based on expectations and assumptions Prosperity and Stellar currently believe to be valid. Because forward-looking statements relate to future results and occurrences, many of which are outside of the control of Prosperity and Stellar, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict. Many possible events or factors could adversely affect the future financial results and performance of Prosperity, Stellar or the combined company and could cause those results or performance to differ materially from those expressed in or implied by the forward-looking statements. Such risks and uncertainties include, among others: (1) the risk that the cost savings and synergies from the proposed transaction may not be fully realized or may take longer than anticipated to be realized, (2) disruption to Prosperity's and Stellar's businesses as a result of the announcements and pendency of the proposed transaction, (3) the risk that the integration of Stellar's businesses and operations into Prosperity will be materially delayed or will be more costly or difficult than expected, or that Prosperity is otherwise unable to successfully integrate Stellar's business into its own, including as a result of unexpected factors or events, (4) the failure to obtain the necessary approval by the shareholders of Stellar, (5) reputational risk and the reaction of each company's customers, suppliers, employees or other business partners to the proposed transaction, (6) the failure of the closing conditions in the Merger Agreement to be satisfied, or any unexpected delay in closing the proposed transaction or the occurrence of any event, change or other circumstances that could give rise to the termination of the Merger Agreement, (7) the dilution caused by the issuances of additional shares of Prosperity's common stock in the proposed transaction, (8) the possibility that the proposed transaction may be more expensive to complete than anticipated, including as a result of unexpected factors or events, (9) the outcome of any legal or regulatory proceedings that may be currently pending or later instituted against Prosperity before or after the proposed transaction, or against Stellar, (10) diversion of management's attention from ongoing business operations and (11) general competitive, economic, political and market conditions and other factors that may affect future results of Prosperity and Stellar. Prosperity and Stellar disclaim any obligation to update such factors or to publicly announce the results of any revisions to any of the forward-looking statements included herein to reflect future events or developments. These and various other risks, uncertainties, assumptions, and factors are discussed in the Annual Reports on Form 10-K for the year ended December 31, 2025, Quarterly Reports on Form 10-Q, and Current Reports on Form 8-K, filed by Prosperity or Stellar and in other filings made by Prosperity and Stellar with the Securities and Exchange Commission (the "SEC") from time to time.

Additional Information about the Transaction and Where to Find It

In connection with the proposed transaction, Prosperity has filed with the SEC a registration statement (the "Registration Statement") on Form S-4 (File No. 333-294882) to register the shares of Prosperity common stock to be issued to the shareholders of Stellar in connection with the proposed transaction. The Registration Statement includes a prospectus of Prosperity and a proxy statement of Stellar included therein (the "proxy statement/prospectus"), which will be sent to the shareholders of Stellar in connection with the proposed transaction. The Registration Statement was declared effective on April 21, 2026, at which time Prosperity filed a final prospectus and Stellar filed a definitive proxy statement. The mailing of the proxy statement/prospectus to Stellar shareholders commenced on or about April 23, 2026. This communication is not a substitute for the Registration Statement, the proxy statement/prospectus or any other document that may be filed by Prosperity or Stellar with the SEC. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE REGISTRATION STATEMENT, THE PROXY STATEMENT/PROSPECTUS INCLUDED WITHIN THE REGISTRATION STATEMENT AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED TRANSACTION OR INCORPORATED BY REFERENCE INTO THE PROXY STATEMENT/PROSPECTUS, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY, BECAUSE THEY CONTAIN OR WILL CONTAIN IMPORTANT INFORMATION. Investors and security holders may obtain the Registration Statement and the proxy statement/prospectus and other documents that are filed with the SEC by Prosperity or Stellar, as applicable, free of charge from the SEC's website at https://www.sec.gov or through the investor relations section of Prosperity's website at https://www.prosperitybankusa.com/investor-relations/ or Stellar's website at https://ir.stellar.bank.

Participants in the Solicitation

Prosperity, Stellar and certain of their directors and executive officers and other employees may be deemed to be participants in the solicitation of proxies from Stellar's shareholders in connection with the proposed transaction. Information about the directors and executive officers of Prosperity and their ownership of Prosperity common stock is contained in the definitive proxy statement for Prosperity's 2026 annual meeting of shareholders (the "Prosperity Annual Meeting Proxy Statement"), which was filed with the SEC on March 16, 2026, including under the headings "Item 1. Election of Directors," "Corporate Governance," "Executive Compensation and Other Matters," "Item 3. Advisory Vote on Executive Compensation," and "Beneficial Ownership of Common Stock by Management of the Company and Principal Shareholders." Information about the directors and executive officers of Stellar and their ownership of Stellar common stock is contained in Amendment No. 1 to the Annual Report on Form 10-K for the year ended December 31, 2025 of Stellar (the "Stellar 10-K/A"), which was filed with the SEC on April 17, 2026. Additional information regarding the persons who may, under the rules of the SEC, be deemed participants in the solicitation of the shareholders of Stellar in connection with the proposed transaction, including a description of their direct or indirect interests, by security holdings or otherwise, is included in the proxy statement/prospectus relating to the proposed transaction filed with the SEC. To the extent holdings of securities by potential participants (or the identity of such participants) have changed since the information printed in the Prosperity Annual Meeting Proxy Statement or the Stellar 10-K/A, such information has been or will be reflected on Statements of Change in Ownership on Forms 3 and 4 filed with the SEC, as applicable. Free copies of the proxy statement/prospectus relating to the proposed transaction and free copies of the other SEC filings to which reference is made in this paragraph may be obtained from the SEC's website at https://www.sec.gov or through the investor relations section of Prosperity's website at https://www.prosperitybankusa.com/investor-relations/ or Stellar's website at https://ir.stellar.bank.

No Offer or Solicitation

This communication is for informational purposes only and is not intended to and does not constitute an offer to subscribe for, buy or sell, or the solicitation of an offer to subscribe for, buy or sell, or an invitation to subscribe for, buy or sell any securities or a solicitation of any vote or approval in any jurisdiction, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in which such offer, invitation, sale or solicitation would be unlawful prior to registration or qualification under the securities laws of any such jurisdiction. No offer of securities shall be made except by means of a prospectus meeting the requirements of Section 10 of the Securities Act, and otherwise in accordance with applicable law.