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8-K

Prosperity Bancshares Inc (PB)

8-K 2025-10-29 For: 2025-10-29
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Added on April 12, 2026

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): October 29, 2025

PROSPERITY BANCSHARES, INC.

(Exact name of registrant as specified in its charter)

Texas 001-35388 74-2331986
(State or other jurisdiction<br><br>of incorporation) (Commission<br><br>File Number) (IRS Employer<br><br>Identification No.)

4295 San Felipe

Houston, Texas 77027

(Address of principal executive offices including zip code)

Registrant's telephone number, including area code: (281) 269-7199

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

Title of each class Trading Symbol(s) Name of each exchange on which registered
Common stock, par value $1.00 per share PB New York Stock Exchange, Inc.

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (17 CFR §230.405) or Rule 12b-2 of the Securities Exchange Act of 1934 (17 CFR §240.12b-2).

Emerging growth company ☐

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. ☐

Item 2.02 Results of Operations and Financial Condition.

On October 29, 2025, Prosperity Bancshares, Inc. publicly disseminated a press release announcing its financial results for the third quarter ended September 30, 2025. A copy of the press release is furnished as Exhibit 99.1 hereto and incorporated herein by reference.

As provided in General Instruction B.2 to Form 8-K, the information furnished in Item 2.02 and Exhibit 99.1 of this Current Report on Form 8-K shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, and such information shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

  • Exhibits. The following is furnished as an exhibit to this Current Report on Form 8-K:
Exhibit<br><br>Number Description of Exhibit
99.1 Press Release issued by Prosperity Bancshares, Inc. dated October 29, 2025.
104 Cover Page Interactive Data File (embedded within the Inline XBRL document).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

PROSPERITY BANCSHARES, INC.<br><br>(Registrant)
Dated: October 29, 2025 By: /s/ Charlotte M. Rasche
Charlotte M. Rasche
Executive Vice President and General Counsel

EX-99.1

Exhibit 99.1

img98618419_0.jpg

PRESS RELEASE For more information contact:
Prosperity Bancshares, Inc.® Cullen Zalman
Prosperity Bank Plaza Executive Vice President – Banking and Corporate Activities
4295 San Felipe 281.269.7199
Houston, Texas 77027 cullen.zalman@prosperitybankusa.com

FOR IMMEDIATE RELEASE

PROSPERITY BANCSHARES, INC.®

REPORTS THIRD QUARTER

2025 EARNINGS

  • Board approved increase in dividend of 3.45% to $0.60 per share for fourth quarter 2025, representing the 22nd consecutive annual increase, with a compound annual growth rate of 10.7%
  • Net income of $137.6 million and earnings per share (diluted) of $1.45 for third quarter 2025
  • Net income of $402.9 million, increased 15.4%, and earnings per share (diluted) of $4.23, increased 14.9%, for the nine months ended September 30, 2025 compared with the same period 2024
  • Third quarter net interest margin increased 29 basis points to 3.24% compared to 2.95% for third quarter 2024
  • Deposits increased $308.7 million during third quarter 2025, or 4.5% annualized
  • Noninterest-bearing deposits of $9.5 billion, representing 34.3% of total deposits
  • Borrowings decreased $500.0 million during third quarter 2025
  • Allowance for credit losses on loans and on off-balance sheet credit exposure of $377.3 million and allowance for credit losses on loans to total loans, excluding Warehouse Purchase Program, of 1.64%(1)
  • Nonperforming assets remain low at 0.36% of third quarter average interest-earning assets
  • Return (annualized) on third quarter average assets of 1.44% and average tangible common equity of 13.43%(1)
  • Announced the signing of a definitive merger agreement with Southwest Bancshares, Inc. headquartered in San Antonio, Texas
  • Pending acquisition of American Bank Holding Corporation, Corpus Christi, Texas

HOUSTON, October 29, 2025. Prosperity Bancshares, Inc.® (NYSE: PB) (“Prosperity Bancshares”), the parent company of Prosperity Bank® (collectively, “Prosperity”), reported net income of $137.6 million for the quarter ended September 30, 2025, compared with $127.3 million for the same period in 2024. Net income per diluted common share was $1.45 for the quarter ended September 30, 2025, compared with $1.34 for the same period in 2024. The annualized return on third quarter average assets was 1.44%. Additionally, deposits increased $308.7 million during the third quarter of 2025. Nonperforming assets remain low at 0.36% of third quarter average interest-earning assets.

“In the third quarter we signed a definitive merger agreement with Southwest Bancshares, Inc., the parent company of Texas Partners Bank, headquartered in San Antonio, Texas. We are excited about this transaction as it significantly expands our San Antonio metro footprint with 4 additional branches and increased deposit market share, bolsters our presence in the Texas Hill Country and adds an experienced C&I lending team,” said David Zalman, Prosperity’s Senior Chairman and Chief Executive Officer.

______________

  • Refer to the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of this non-GAAP financial measure to the nearest GAAP financial measure.

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“I would also be remiss not to mention how excited we are about our pending merger with American Bank Holding Corporation in Corpus Christi, Texas. The combination will strengthen our presence and operations in South Texas and surrounding areas and enhance our presence in Central Texas, including San Antonio,” continued Zalman.

“I am also pleased to announce that the Board of Directors approved increasing the fourth quarter 2025 dividend to $0.60 per share from $0.58 per share that was paid in the prior four quarters. The increase reflects the continued confidence the Board has in our company and our markets. The compound annual growth rate in dividends declared from 2003 to 2025 was 10.7%. We continue to share our success with our shareholders through the payment of dividends and opportunistic stock repurchases, while also continuing to grow our capital,” stated Zalman.

“As of October 2025, Texas boasts one of the world's strongest and most diverse economies, ranking as the 8th largest globally with a GDP of approximately $2.77 trillion in 2024. The state produces about 9.3% of U.S. GDP and continues to outpace national growth in many metrics. Although the economy is showing some signs of moderation, influenced by factors such as tariffs and immigration policies, we believe Texas remains the best state for business with a pro-business attitude and no state income tax. This is evidenced by major corporations continuing to move their operations to Texas and Oklahoma,” added Zalman.

“As of October 2025, Oklahoma's economy is demonstrating resilience and modest growth, outpacing national averages in key areas such as unemployment and population expansion despite broader U.S. slowdowns from tariffs and policy uncertainties,” continued Zalman.

“I would like to thank our customers, associates, directors and shareholders for their hard work and loyalty. Our fundamentals and resolve have never been stronger to continue to build this successful company,” concluded Zalman.

Results of Operations for the Three Months Ended September 30, 2025

Net income was $137.6 million(2) for the three months ended September 30, 2025, compared with $127.3 million(3) for the same period in 2024, an increase of $10.3 million or 8.1%. Net income per diluted common share was $1.45 for the three months ended September 30, 2025, compared with $1.34 for the same period in 2024, an increase of 8.2%. The changes were primarily due to an increase in net interest income, partially offset by an increase in provision for income taxes. On a linked quarter basis, net income was $137.6 million(2) for the three months ended September 30, 2025, compared with $135.2 million(4) for the three months ended June 30, 2025, an increase of $2.4 million or 1.8%. Net income per diluted common share was $1.45 for the three months ended September 30, 2025, compared with $1.42 for the three months ended June 30, 2025. Annualized returns on average assets, average common equity and average tangible common equity for the three months ended September 30, 2025, were 1.44%, 7.18% and 13.43%(1), respectively. Prosperity’s efficiency ratio (excluding net gains and losses on the sale, write-down or write-up of assets and securities) was 44.06%(1) for the three months ended September 30, 2025.

Net interest income before provision for credit losses was $273.4 million for the three months ended September 30, 2025, compared with $261.7 million for the same period in 2024, an increase of $11.7 million or 4.5%. The change was primarily due to a decrease in the average balances and average rates on other borrowings and a decrease in the average rates on interest-bearing deposits, partially offset by a decrease in the average balances and average rates on federal funds sold and other earning assets, a decrease in the average balances and average rates on loans and a decrease in loan discount accretion of $2.0 million. Net interest income before provision for credit losses increased $5.7 million or 2.1% to $273.4 million for the three months ended September 30, 2025, compared with $267.7 million for the three months ended June 30, 2025, primarily due to one extra day during the current quarter and a decrease in the average balances for other borrowings.

The net interest margin on a tax equivalent basis was 3.24% for the three months ended September 30, 2025, compared with 2.95% for the same period in 2024. The change was primarily due to a decrease in the average balances and average rates on other borrowings and a decrease in the average rates on interest-bearing deposits, partially offset by a decrease in the average balances and average rates

______________

  • Includes purchase accounting adjustments of $2.6 million, net of tax, primarily comprised of loan discount accretion of $2.9 million for the three months ended September 30, 2025.
  • Includes purchase accounting adjustments of $4.3 million, net of tax, primarily comprised of loan discount accretion of $4.8 million for the three months ended September 30, 2024.
  • Includes purchase accounting adjustments of $2.8 million, net of tax, primarily comprised of loan discount accretion of $3.1 million for the three months ended June 30, 2025.
  • Includes purchase accounting adjustments of $8.5 million, net of tax, primarily comprised of loan discount accretion of $9.3 million for the nine months ended September 30, 2025.
  • Includes purchase accounting adjustments of $12.4 million, net of tax, primarily comprised of loan discount accretion of $13.9 million, merger related provision for credit losses of $9.1 million, merger related expenses of $4.4 million, FDIC special assessment of $3.6 million, and net gain on sale or write-up of securities of $11.2 million for the nine months ended September 30, 2024.

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on federal funds sold and other earning assets, a decrease in the average balances and average rates on loans and a decrease in loan discount accretion of $2.0 million. The net interest margin on a tax equivalent basis was 3.24% for the three months ended September 30, 2025, compared with 3.18% for the three months ended June 30, 2025, primarily due to a decrease in the average balances for other borrowings.

Noninterest income was $41.2 million for the three months ended September 30, 2025, compared with $41.1 million for the same period in 2024. Noninterest income was $41.2 million for the three months ended September 30, 2025, compared with $43.0 million for the three months ended June 30, 2025, a decrease of $1.7 million. The change was primarily due to a decrease in net gain on sale or write-down of assets.

Noninterest expense was $138.6 million for the three months ended September 30, 2025, compared with $140.3 million for the same period in 2024, a decrease of $1.7 million, primarily due to a decrease in other noninterest expense. Noninterest expense was $138.6 million for the three months ended September 30, 2025, and the three months ended June 30, 2025.

Results of Operations for the Nine Months Ended September 30, 2025

For the nine months ended September 30, 2025, net income was $402.9 million(5) compared with $349.3 million(6) for the same period in 2024, an increase of $53.6 million or 15.4%. Net income per diluted common share was $4.23 for the nine months ended September 30, 2025, compared with $3.68 for the same period in 2024, an increase of 14.9%. The changes were primarily due to an increase in net interest income, lower merger related provision and expenses, and lower regulatory assessments and FDIC insurance, partially offset by a decrease in net gain on sale or write-up of securities. Returns on average assets, average common equity and average tangible common equity for the nine months ended September 30, 2025, were 1.40%, 7.08% and 13.36%(1), respectively.

Net interest income before provision for credit losses for the nine months ended September 30, 2025, was $806.5 million compared with $758.7 million for the same period in 2024, an increase of $47.8 million or 6.3%. The change was primarily due to a decrease in the average balances and average rates on other borrowings and a decrease in the average rates on interest-bearing deposits, partially offset by a decrease in the average balances on investment securities, a decrease in the average balances and average rates on federal funds sold and other earning assets, a decrease in loan discount accretion of $4.6 million and a decrease in the average balances on loans.

The net interest margin on a tax equivalent basis for the nine months ended September 30, 2025, was 3.19% compared with 2.86% for the same period in 2024. The change was primarily due to a decrease in the average balances and average rates on other borrowings and a decrease in the average rates on interest-bearing deposits, partially offset by a decrease in the average balances on investment securities, a decrease in the average balances and average rates on federal funds sold and other earning assets, a decrease in loan discount accretion of $4.6 million and a decrease in the average balances on loans.

Noninterest income was $125.5 million for the nine months ended September 30, 2025, compared with $126.0 million for the same period in 2024.

Noninterest expense was $417.5 million for the nine months ended September 30, 2025, compared with $429.0 million for the same period in 2024, a decrease of $11.5 million or 2.7%, primarily due to decreases in regulatory assessment and FDIC insurance, merger related expenses and other noninterest expense.

Balance Sheet Information

Prosperity had $38.330 billion in total assets at September 30, 2025, compared with $38.417 billion at June 30, 2025, and $40.115 billion at September 30, 2024. The decrease was primarily due to the reduction in borrowings by $1.50 billion from September 30, 2024 to September 30, 2025.

Loans were $22.028 billion at September 30, 2025, a decrease of $169.6 million from $22.197 billion at June 30, 2025. Loans decreased $353.1 million from $22.381 billion at September 30, 2024.

Loans, excluding Warehouse Purchase Program loans, were $20.750 billion at September 30, 2025, compared with $20.910 billion at June 30, 2025, a decrease of $160.4 million, and compared with $21.152 billion at September 30, 2024, a decrease of $402.6 million.

Deposits were $27.782 billion at September 30, 2025, an increase of $308.7 million or 1.1% from $27.473 billion at June 30, 2025. Deposits decreased $305.5 million from $28.088 billion at September 30, 2024.

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Asset Quality

Nonperforming assets totaled $119.6 million or 0.36% of quarterly average interest-earning assets at September 30, 2025, compared with $110.5 million or 0.33% of quarterly average interest-earning assets at June 30, 2025, and $89.9 million or 0.25% of quarterly average interest-earning assets at September 30, 2024, with a significant portion of the balance for each period attributable to acquired loans.

The allowance for credit losses on loans and off-balance sheet credit exposures was $377.3 million at September 30, 2025, compared with $383.7 million at June 30, 2025, and $392.0 million at September 30, 2024. There was no provision for credit losses for the three and nine months ended September 30, 2025, compared to no provision for credit losses for the three months ended September 30, 2024, and a $9.1 million provision for credit losses for the nine months ended September 30, 2024.

The allowance for credit losses on loans was $339.6 million or 1.54% of total loans at September 30, 2025, compared with $346.1 million or 1.56% of total loans at June 30, 2025, and $354.4 million or 1.58% of total loans at September 30, 2024. Excluding Warehouse Purchase Program loans, the allowance for credit losses on loans to total loans was 1.64%(1) at September 30, 2025, compared with 1.66%(1) at June 30, 2025, and 1.68%(1) at September 30, 2024.

Net charge-offs were $6.5 million for the three months ended September 30, 2025, compared with net charge-offs of $3.0 million for the three months ended June 30, 2025, and net charge-offs of $5.5 million for the three months ended September 30, 2024. For the three months ended September 30, 2025, $4.5 million of reserves on resolved purchased credit deteriorated (“PCD”) loans without any related charge-offs were released to the general reserve.

Net charge-offs were $12.2 million for the nine months ended September 30, 2025, compared with net charge-offs of $12.0 million for the nine months ended September 30, 2024. For the nine months ended September 30, 2025, $15.0 million of reserves on resolved PCD loans without any related charge-offs were released to the general reserve.

Dividend

Prosperity Bancshares declared a fourth quarter 2025 cash dividend of $0.60 per share to be paid on January 2, 2026, to all shareholders of record as of December 15, 2025, an increase of $0.02 per share, or 3.45%, from the prior quarter.

Stock Repurchase Program

On January 21, 2025, Prosperity Bancshares announced a stock repurchase program under which up to 5%, or approximately 4.8 million shares, of its outstanding common stock may be acquired over a one-year period expiring on January 21, 2026, at the discretion of management. Under its 2025 stock repurchase program, Prosperity Bancshares repurchased 299,318 shares of its common stock at an average weighted price of $66.62 per share during the three and nine months ended September 30, 2025.

Agreement to Acquire Southwest Bancshares, Inc.

On October 1, 2025, Prosperity Bancshares and Southwest Bancshares, Inc. (“Southwest) jointly announced the signing of a definitive merger agreement (the “Prosperity/Southwest Merger Agreement”) whereby Southwest, a Texas corporation and bank holding company of Texas Partners Bank (“Texas Partners”), will merge with and into Prosperity Bancshares and Texas Partners will merge with and into Prosperity Bank. Texas Partners operates 11 banking offices in Central Texas including its main office in San Antonio, and banking offices in the San Antonio area, Austin and the Hill Country. As of June 30, 2025, Southwest, on a consolidated basis, reported total assets of $2.354 billion, total loans of $1.890 billion and total deposits of $2.129 billion.

Under the terms and subject to the conditions of the Prosperity/Southwest Merger Agreement, Prosperity Bancshares will issue 4,062,520 shares of Prosperity Bancshares common stock for all outstanding shares of Southwest common stock and restricted stock awards, subject to certain potential adjustments. Southwest warrants and in-the-money Southwest stock options that are outstanding at the closing will be converted into cash payments based on the value of the merger consideration (less the applicable exercise price), as calculated pursuant to the terms of the Prosperity/Southwest Merger Agreement. Based on Prosperity Bancshares’s closing price of $65.97 on September 29, 2025, the total consideration was valued at approximately $268.9 million. The transaction is subject to customary closing conditions, including the receipt of regulatory approvals and approval by the shareholders of Southwest. The transaction is expected to close during the first quarter of 2026.

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Pending Acquisition of American Bank Holding Corporation

On July 18, 2025, Prosperity Bancshares and American Bank Holding Corporation (“American”) jointly announced the signing of a definitive merger agreement (the “Prosperity/American Merger Agreement”) whereby American, a Texas corporation and bank holding company of American Bank, N.A. (“American Bank”), will merge with and into Prosperity Bancshares and American Bank will merge with and into Prosperity Bank. American Bank operates 18 banking offices and 2 loan production offices in South and Central Texas including its main office in Corpus Christi, and banking offices in San Antonio, Austin, Victoria and the greater Corpus Christi area including Port Aransas and Rockport and a loan production office in Houston, Texas. As of June 30, 2025, American, on a consolidated basis, reported total assets of $2.553 billion, total loans of $1.798 billion and total deposits of $2.293 billion.

Under the terms and subject to the conditions of the Prosperity/American Merger Agreement, Prosperity Bancshares will issue 4,439,981 shares of Prosperity Bancshares common stock for all outstanding shares of American common stock, subject to certain potential adjustments. Based on Prosperity Bancshares’ closing price of $72.40 on July 16, 2025, the total consideration was valued at approximately $321.5 million. The transaction is subject to customary closing conditions, including the receipt of required regulatory approvals and approval of the shareholders of American. The transaction is expected to close during the fourth quarter of 2025 or the first quarter of 2026.

Conference Call

Prosperity’s management team will host a conference call on Wednesday, October 29, 2025, at 11:30 a.m. Eastern Time (10:30 a.m. Central Time) to discuss Prosperity’s third quarter 2025 earnings. Individuals and investment professionals may participate in the call by dialing 877-883-0383 for domestic participants, or 412-902-6506 for international participants. The participant elite entry number is 2818776.

Alternatively, individuals may listen to the live webcast of the presentation by visiting Prosperity’s website at www.prosperitybankusa.com. The webcast may be accessed from Prosperity’s Investor Relations page by selecting “Presentations, Webcasts & Calls” from the menu and following the instructions.

Non-GAAP Financial Measures

Prosperity’s management uses certain non-GAAP financial measures to evaluate its performance. Specifically, for internal planning and forecasting purposes, Prosperity reviews each of diluted earnings per share, return on average assets, return on average common equity, and return on average tangible common equity, in each case excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, Federal Deposit Insurance Corporation (“FDIC”) special assessment, net of tax, and net gain on the sale or write-up of securities, net of tax; return on average tangible common equity; tangible book value per share; the tangible equity to tangible assets ratio; allowance for credit losses to total loans excluding Warehouse Purchase Program loans; the efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities; and the efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities, merger related expenses, and FDIC special assessment. Prosperity believes these non-GAAP financial measures provide information useful to investors in understanding Prosperity’s financial results and their presentation, together with the accompanying reconciliations, provides a more complete understanding of factors and trends affecting Prosperity’s business and allows investors to view performance in a manner similar to management, the entire financial services sector, bank stock analysts and bank regulators. Further, Prosperity believes that these non-GAAP financial measures provide useful information by excluding certain items that may not be indicative of its core operating earnings and business outlook. These non-GAAP financial measures should not be considered a substitute for, nor of greater importance than, GAAP basis financial measures and results; Prosperity strongly encourages investors to review its consolidated financial statements in their entirety and not to rely on any single financial measure. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures having the same or similar names. Please refer to the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of these non-GAAP financial measures to the nearest respective GAAP financial measures.

Prosperity Bancshares, Inc. ®

As of September 30, 2025, Prosperity Bancshares, Inc.® is a $38.330 billion Houston, Texas based regional financial holding company providing personal banking services and investments to consumers and businesses throughout Texas and Oklahoma. Founded in 1983, Prosperity believes in a community banking philosophy, taking care of customers, businesses and communities in the areas it serves by providing financial solutions to simplify everyday financial needs. In addition to offering traditional deposit and loan products, Prosperity offers digital banking solutions, credit and debit cards, mortgage services, retail brokerage services, trust and wealth management, and treasury management.

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Prosperity currently operates 283 full-service banking locations: 62 in the Houston area, including The Woodlands; 33 in the South Texas area including Corpus Christi and Victoria; 61 in the Dallas/Fort Worth area; 22 in the East Texas area; 31 in the Central Texas area including Austin and San Antonio; 45 in the West Texas area including Lubbock, Midland-Odessa, Abilene, Amarillo and Wichita Falls; 15 in the Bryan/College Station area; 6 in the Central Oklahoma area; and 8 in the Tulsa, Oklahoma area.

Cautionary Notes on Forward-Looking Statements

“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995: This release contains, and the remarks by Prosperity’s management on the conference call may contain, statements regarding the proposed transactions between (1) Prosperity Bancshares, Inc. (“Prosperity”) and Southwest Bancshares, Inc. (“Southwest”) and (2) Prosperity and American Bank Holding Corporation (“American”); future financial and operating results; benefits and synergies of the transactions; future opportunities for Prosperity; the issuances of common stock of Prosperity contemplated by the Agreement and Plan of Merger by and between Prosperity and Southwest (the “Prosperity/Southwest Merger Agreement”) and the Agreement and Plan of Merger by and between Prosperity and American (the “Prosperity/American Merger Agreement” and, together with the Prosperity/Southwest Merger Agreement, the “Merger Agreements”); in connection with the proposed transaction between Prosperity and Southwest, the expected filing by Prosperity with the Securities and Exchange Commission (the “SEC”) of a registration statement on Form S-4 (the “Prosperity/Southwest Registration Statement”) and a prospectus of Prosperity and a proxy statement of Southwest to be included therein (the “Prosperity/Southwest Proxy Statement/Prospectus”); in connection with the proposed transaction between Prosperity and American, a registration statement on Form S-4 (the “Prosperity/American Registration Statement” and, together with the Prosperity/Southwest Registration Statement, the “Registration Statements”) and a preliminary prospectus of Prosperity and a proxy statement of American included therein (the “Prosperity/American Proxy Statement/ Prospectus” and, together with the Southwest Proxy Statement/ Prospectus, the “Proxy Statement/ Prospectuses”), which registration statement was filed with the SEC on September 17, 2025, and amended on September 30, 2025; the expected timing of the closing of the proposed transactions; the ability of the parties to complete the proposed transactions 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 and its subsidiaries or related to the proposed transactions between (1) Prosperity and Southwest and (2) Prosperity and American 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 possible or assumed future economic performance or future results of operations, including future revenues, income, expenses, provision for credit losses, provision for taxes, effective tax rate, earnings per share and cash flows and Prosperity’s future capital expenditures and dividends, future financial condition and changes therein, including changes in Prosperity’s loan portfolio and allowance for credit losses, future capital structure or changes therein, as well as the plans and objectives of management for Prosperity’s future operations, future or proposed acquisitions, the future or expected effect of acquisitions on Prosperity’s operations, results of operations, financial condition, and future economic performance, statements about the anticipated benefits of each of the proposed transactions, 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 currently believes to be valid. Because forward-looking statements relate to future results and occurrences, many of which are outside of Prosperity’s control, they are subject to inherent uncertainties, risks and changes in circumstances that are difficult to predict. These risks and uncertainties include, but are not limited to, whether Prosperity can: successfully identify acquisition targets and integrate the businesses of acquired companies and banks; continue to sustain its current internal growth rate or total growth rate; provide products and services that appeal to its customers; continue to have access to debt and equity capital markets; and achieve its sales objectives. Other risks include, but are not limited to: the possibility that credit quality could deteriorate; actions of competitors; changes in laws and regulations (including changes in governmental interpretations of regulations and changes in accounting standards); a deterioration or downgrade in the credit quality and credit agency ratings of the securities in Prosperity’s securities portfolio; customer and consumer demand, including customer and consumer response to marketing; effectiveness of spending, investments or programs; fluctuations in the cost and availability of supply chain resources; economic conditions, including currency rate, interest rate and commodity price fluctuations; changes in trade policies by the United States or other countries, such as tariffs or retaliatory tariffs; and

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the effect, impact, potential duration or other implications of weather and climate-related events. Many possible events or factors could adversely affect the future financial results and performance of Prosperity, Southwest or American 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 transactions may not be fully realized or may take longer than anticipated to be realized, (2) disruption to Prosperity’s, Southwest’s and American’s businesses as a result of the announcements and pendency of the transactions, (3) the risk that the integration of Southwest’s and/or American’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 Southwest’s and/or American’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 Southwest and/or American, (5) the ability by each of Prosperity, Southwest and/or American to obtain required governmental approvals of the transactions on the timeline expected, or at all, and the risk that such approvals may result in the imposition of conditions that could adversely affect Prosperity after the closing of the transactions or adversely affect the expected benefits of the transactions, (6) reputational risk and the reaction of each company’s customers, suppliers, employees or other business partners to the transactions, (7) the failure of the closing conditions in the applicable Merger Agreements to be satisfied, or any unexpected delay in closing the transactions or the occurrence of any event, change or other circumstances that could give rise to the termination of the applicable Merger Agreements, (8) the dilution caused by the issuances of additional shares of Prosperity’s common stock in the transactions, (9) the possibility that the transactions may be more expensive to complete than anticipated, including as a result of unexpected factors or events, (10) the outcome of any legal or regulatory proceedings that may be currently pending or later instituted against Prosperity before or after any of the transactions, or against Southwest or American, (11) diversion of management’s attention from ongoing business operations and (12) general competitive, economic, political and market conditions and other factors that may affect future results of Prosperity, Southwest and American. Prosperity disclaims 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 factors are discussed in Prosperity’s Annual Report on Form 10-K, Quarterly Reports on Form 10- Q, and Current Reports on Form 8-K, in each case filed with the SEC, and other reports and statements Prosperity has filed with the SEC. Copies of the SEC filings for Prosperity may be downloaded from the Internet at no charge from http://www.prosperitybankusa.com.

Additional Information about the Transactions and Where to Find It

Prosperity intends to file with the SEC the Prosperity/Southwest Registration Statement on Form S-4 to register the shares of Prosperity common stock to be issued to the shareholders of Southwest in connection with Prosperity’s and Southwest’s proposed transaction. The Prosperity/Southwest Registration Statement will include the Prosperity/Southwest Proxy Statement/Prospectus which will be sent to the shareholders of Southwest in connection with the proposed transaction. This communication is not a substitute for the Prosperity/Southwest Proxy Statement/Prospectus or any other document which Prosperity may file with the SEC. In connection with Prosperity’s and American’s proposed transaction, Prosperity has filed with the SEC on September 17, 2025 the Prosperity/American Registration Statement on Form S-4, as amended on September 30, 2025, (the “Amended Prosperity/American Registration Statement”) (which Amended Prosperity/American Registration Statement was declared effective by the SEC on September 30, 2025), to register the shares of Prosperity common stock to be issued to the shareholders of American in connection with Prosperity’s and American’s proposed transaction. The Prosperity/American Proxy Statement/Prospectus will be delivered to shareholders of American. Prosperity may also file other documents with the SEC regarding the proposed transaction. This communication is not a substitute for the Prosperity/American Proxy Statement/Prospectus or Amended Prosperity/American Registration Statement or any other document which Prosperity may file with the SEC. INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE APPLICABLE REGISTRATION STATEMENT ON FORM S-4, THE APPLICABLE PROXY STATEMENT/PROSPECTUS INCLUDED WITHIN THE APPLICABLE REGISTRATION STATEMENT ON FORM S-4 AND ANY OTHER RELEVANT DOCUMENTS TO BE FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED TRANSACTIONS OR INCORPORATED BY REFERENCE INTO THE APPLICABLE PROXY/STATEMENT PROSPECTUS, AS WELL AS ANY AMENDMENTS OR SUPPLEMENTS TO THESE DOCUMENTS, CAREFULLY AND IN THEIR ENTIRETY, BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT PROSPERITY, SOUTHWEST, AMERICAN AND THE APPLICABLE PROPOSED TRANSACTIONS. Investors and security holders may obtain free copies of these documents through the website maintained by the SEC at http://www.sec.gov. You will also be able to obtain these documents, free of charge, from Prosperity at http://www.prosperitybankusa.com. Copies of the Prosperity/American Proxy Statement/Prospectus (and the Prosperity/Southwest Proxy Statement/Prospectus, when it becomes available), can also be obtained, free of charge, by directing a request by telephone or mail to Prosperity Bancshares, Inc., Prosperity Bank Plaza, 4295 San Felipe, Houston, Texas 77027 Attn: Investor Relations, (281) 269-7199, or with respect to the Prosperity/American Proxy Statement/Prospectus, to American Bank Holding Corporation, 800 North Shoreline Boulevard, Corpus Christi, Texas 78401, Attn: Stephen Raffaele, (512) 306-5550 or, with respect to the Prosperity/Southwest Proxy Statement/Prospectus, Southwest Bancshares, Inc., 1900 NW Loop 410, San Antonio, Texas 78213, Attention: Investor Relations, (210) 807-5511, as applicable.

Page 7

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.

Page 8

Bryan/College Station Area Grapevine Seven Points Shadow Creek North University
Bryan Grapevine Main Teague Spring Texas Tech Student Union
Bryan-29th Street Kiest Tyler-Beckham Tomball
Bryan-East Lake Highlands Tyler-South Broadway Waller Midland
Bryan-North McKinney Tyler-University West Columbia North
Caldwell McKinney Eldorado Winnsboro Wharton Wadley
College Station McKinney Redbud Winnie Wall Street
Hearne North Carrolton Houston Area Wirt West
Huntsville Park Cities Houston
Madisonville Plano Aldine South Texas Area - Odessa
Navasota Plano-West Alief Corpus Christi Grant
New Waverly Preston Forest Bellaire Calallen Kermit Highway
Rock Prairie Preston Parker Beltway Carmel Parkway
Southwest Parkway Preston Royal Clear Lake Northwest
Tower Point Red Oak Copperfield Saratoga San Angelo
Wellborn Road Richardson Cypress Timbergate College Hills
Richardson-West Downtown Water Street Sherwood Way
Central Texas Area Rosewood Court Eastex
Austin The Colony Fairfield Victoria Wichita Falls
Cedar Park Tollroad First Colony Victoria Main Cattlemans
Congress Trinity Mills Fry Road Victoria-Navarro Kell
Lakeway Turtle Creek Gessner Victoria-North
Liberty Hill West 15th Plano Gladebrook Victoria Salem Other West Texas Area
Northland West Allen Grand Parkway Locations
Oak Hill Westmoreland Heights Other South Texas Area Big Spring
Research Blvd Wylie Highway 6 West Locations Big Spring - East
Westlake Little York Alice Brownfield
Fort Worth Medical Center Aransas Pass Brownwood
Other Central Texas Area Haltom City Memorial Drive Bay City Burkburnett
Locations Hulen Northside Beeville Byers
Bastrop Keller Pasadena Colony Creek Cisco
Canyon Lake Museum Place Pecan Grove Cuero Comanche
Dime Box Renaissance Square Pin Oak East Bernard Early
Dripping Springs Roanoke River Oaks Edna Floydada
Elgin Stockyards Sugar Land El Campo Gorman
Flatonia SW Medical Center Goliad Henrietta
Fredericksburg Other Dallas/Fort Worth Area Tanglewood Gonzales Levelland
Georgetown Locations The Plaza Hallettsville Littlefield
Gruene Arlington Uptown Kingsville Merkel
Horseshoe Bay Azle Waugh Drive Mathis Plainview
Kingsland Ennis Westheimer Padre Island Slaton
La Grange Gainesville West University Palacios Snyder
Lexington Glen Rose Woodcreek Port Lavaca
Marble Falls Granbury Portland Oklahoma
New Braunfels Grand Prairie Katy Rockport Central Oklahoma Area
Pleasanton Jacksboro Cinco Ranch Sinton Oklahoma City
Round Rock Mesquite Katy-Spring Green Taft 23rd Street
San Antonio Muenster Yoakum Expressway
Schulenburg Runaway Bay The Woodlands Yorktown I-240
Seguin Sanger The Woodlands-College Park Memorial
Smithville Waxahachie The Woodlands-I-45 West Texas Area
Thorndale Weatherford The Woodlands-Research Forest Abilene Other Central Oklahoma Area
Weimar Antilley Road Locations
East Texas Area Other Houston Area Barrow Street Edmond
Dallas/Fort Worth Area Athens Locations Cypress Street Norman
Dallas Blooming Grove Angleton Judge Ely
14th Street Plano Canton Beaumont Mockingbird Tulsa Area
Abrams Centre Carthage Cleveland Tulsa
Addison Corsicana Dayton Amarillo Garnett
Allen Crockett Galveston Hillside Harvard
Balch Springs Eustace Groves Soncy Memorial
Camp Wisdom Gilmer Hempstead Sheridan
Carrollton Grapeland Hitchcock Lubbock S. Harvard
Cedar Hill Gun Barrel City Liberty 4th Street Utica Tower
Coppell Jacksonville Magnolia 66th Street Yale
East Plano Kerens Magnolia Parkway 82nd Street
Frisco Longview Mont Belvieu 86th Street Other Tulsa Area Locations
Frisco Warren Mount Vernon Nederland 110th Street Owasso
Frisco-West Palestine Needville Avenue Q
Garland Rusk Rosenberg Milwaukee

Page 9

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(In thousands)

Sep 30, 2025 Jun 30, 2025 Mar 31, 2025 Dec 31, 2024 Sep 30, 2024
Balance Sheet Data (at period end)
Loans held for sale $ 11,297 $ 6,004 $ 9,764 $ 10,690 $ 6,113
Loans held for investment 20,738,294 20,903,944 20,909,913 21,057,616 21,146,033
Loans held for investment - Warehouse Purchase Program 1,278,178 1,287,440 1,057,893 1,080,903 1,228,706
Total loans 22,027,769 22,197,388 21,977,570 22,149,209 22,380,852
Investment securities(A) 10,232,462 10,608,104 10,792,731 11,094,424 11,300,756
Federal funds sold 210 197 221 292 208
Allowance for credit losses on loans (339,626 ) (346,084 ) (349,101 ) (351,805 ) (354,397 )
Cash and due from banks 1,766,115 1,304,993 1,694,637 1,972,175 2,209,863
Goodwill 3,503,127 3,503,127 3,503,127 3,503,129 3,504,388
Core deposit intangibles, net 55,194 58,796 62,406 66,047 70,178
Other real estate owned 13,750 7,874 8,012 5,701 5,757
Fixed assets, net 378,776 374,602 373,273 371,238 373,812
Other assets 692,692 708,355 701,799 756,328 623,903
Total assets $ 38,330,469 $ 38,417,352 $ 38,764,675 $ 39,566,738 $ 40,115,320
Noninterest-bearing deposits $ 9,522,028 $ 9,426,657 $ 9,675,915 $ 9,798,438 $ 9,811,361
Interest-bearing deposits 18,260,066 18,046,754 18,350,884 18,582,900 18,276,250
Total deposits 27,782,094 27,473,411 28,026,799 28,381,338 28,087,611
Other borrowings 2,400,000 2,900,000 2,700,000 3,200,000 3,900,000
Securities sold under repurchase agreements 185,797 183,572 216,086 221,913 228,896
Allowance for credit losses on off-balance sheet credit exposures 37,646 37,646 37,646 37,646 37,646
Other liabilities 259,994 222,987 267,083 287,346 499,918
Total liabilities 30,665,531 30,817,616 31,247,614 32,128,243 32,754,071
Shareholders' equity(B) 7,664,938 7,599,736 7,517,061 7,438,495 7,361,249
Total liabilities and equity $ 38,330,469 $ 38,417,352 $ 38,764,675 $ 39,566,738 $ 40,115,320

(A) Includes $(1,987), $(1,657), $(1,374), $(2,056) and $(1,070) in unrealized losses on available for sale securities for the quarterly periods ended September 30, 2025, June 30, 2025, March 31, 2025, December 31, 2024 and September 30, 2024 respectively.

(B) Includes $(1,570), $(1,309), $(1,085), $(1,624) and $(845) in after-tax unrealized losses on available for sale securities for the quarterly periods ended September 30, 2025, June 30, 2025, March 31, 2025, December 31, 2024 and September 30, 2024, respectively.

Page 10

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(In thousands)

Three Months Ended Year-to-Date
Sep 30,<br>2025 Jun 30,<br>2025 Mar 31,<br>2025 Dec 31,<br>2024 Sep 30,<br>2024 Sep 30,<br>2025 Sep 30,<br>2024
Income Statement Data
Interest income:
Loans $ 329,445 $ 325,490 $ 319,023 $ 333,055 $ 337,451 $ 973,958 $ 980,107
Securities(C) 58,207 57,836 57,886 58,260 59,617 173,929 188,466
Federal funds sold and other earning assets 10,455 9,438 15,896 19,630 20,835 35,789 44,195
Total interest income 398,107 392,764 392,805 410,945 417,903 1,183,676 1,212,768
Interest expense:
Deposits 95,965 93,790 95,597 102,050 107,758 285,352 306,574
Other borrowings 27,613 30,101 30,492 39,620 46,792 88,206 142,020
Securities sold under repurchase agreements 1,094 1,151 1,334 1,501 1,662 3,579 5,453
Total interest expense 124,672 125,042 127,423 143,171 156,212 377,137 454,047
Net interest income 273,435 267,722 265,382 267,774 261,691 806,539 758,721
Provision for credit losses 9,066
Net interest income after provision for credit losses 273,435 267,722 265,382 267,774 261,691 806,539 749,655
Noninterest income:
Nonsufficient funds (NSF) fees 9,805 8,885 9,147 9,960 9,016 27,837 25,457
Credit card, debit card and ATM card income 9,446 9,761 8,739 9,443 9,620 27,946 27,865
Service charges on deposit accounts 7,317 7,645 7,408 6,992 6,664 22,370 19,506
Trust income 3,526 3,859 3,601 3,514 3,479 10,986 11,236
Mortgage income 931 965 1,009 779 962 2,905 2,317
Brokerage income 1,328 1,225 1,262 1,063 1,258 3,815 3,679
Bank owned life insurance income 2,111 1,985 2,115 2,020 2,028 6,211 5,960
Net gain (loss) on sale or write-down of assets 3 1,414 (235 ) 584 3,178 1,182 2,240
Net gain on sale or write-up of securities 224 11,245
Other noninterest income 6,771 7,243 8,255 5,482 4,670 22,269 16,467
Total noninterest income 41,238 42,982 41,301 39,837 41,099 125,521 125,972
Noninterest expense:
Salaries and benefits 87,949 87,296 89,476 88,631 88,367 264,721 263,722
Net occupancy and equipment 9,395 9,168 9,146 8,957 9,291 27,709 26,829
Credit and debit card, data processing and software amortization 12,515 12,056 11,422 12,342 11,985 35,993 34,958
Regulatory assessments and FDIC insurance 5,198 5,508 5,789 5,789 5,726 16,495 21,581
Core deposit intangibles amortization 3,602 3,610 3,641 4,131 4,146 10,853 11,539
Depreciation 4,966 4,779 4,774 4,791 4,741 14,519 14,263
Communications 3,480 3,507 3,473 3,450 3,360 10,460 10,247
Other real estate expense 314 204 140 255 12 658 268
Net (gain) loss on sale or write-down of other real estate (81 ) (222 ) (30 ) (610 ) (97 ) (333 ) (204 )
Merger related expenses 62 63 62 4,444
Other noninterest expense 11,235 12,659 12,470 13,809 12,744 36,364 41,381
Total noninterest expense 138,635 138,565 140,301 141,545 140,338 417,501 429,028
Income before income taxes 176,038 172,139 166,382 166,066 162,452 514,559 446,599
Provision for income taxes 38,482 36,984 36,157 35,990 35,170 111,623 97,289
Net income available to common shareholders $ 137,556 $ 135,155 $ 130,225 $ 130,076 $ 127,282 $ 402,936 $ 349,310

(C) Interest income on securities was reduced by net premium amortization of $2,877, $4,926, $5,027, $5,609 and $5,574 for the three months ended September 30, 2025, June 30, 2025, March 31, 2025, December 31, 2024 and September 30, 2024, respectively, and $12,830 and $17,227 for the nine months ended September 30, 2025 and 2024, respectively.

Page 11

Prosperity Bancshares, Inc. ®

Financial Highlights (Unaudited)

(Dollars and share amounts in thousands, except per share data and market prices)

Three Months Ended Year-to-Date
Sep 30,<br>2025 Jun 30,<br>2025 Mar 31,<br>2025 Dec 31,<br>2024 Sep 30,<br>2024 Sep 30,<br>2025 Sep 30,<br>2024
Profitability
Net income (D) (E) $ 137,556 $ 135,155 $ 130,225 $ 130,076 $ 127,282 $ 402,936 $ 349,310
Basic earnings per share $ 1.45 $ 1.42 $ 1.37 $ 1.37 $ 1.34 $ 4.23 $ 3.68
Diluted earnings per share $ 1.45 $ 1.42 $ 1.37 $ 1.37 $ 1.34 $ 4.23 $ 3.68
Return on average assets (F) (J) 1.44 % 1.41 % 1.34 % 1.31 % 1.28 % 1.40 % 1.16 %
Return on average common equity (F) (J) 7.18 % 7.13 % 6.94 % 7.00 % 6.93 % 7.08 % 6.40 %
Return on average tangible common equity (F) (G) (J) 13.43 % 13.44 % 13.23 % 13.50 % 13.50 % 13.36 % 12.43 %
Tax equivalent net interest margin (D) (E) (H) 3.24 % 3.18 % 3.14 % 3.05 % 2.95 % 3.19 % 2.86 %
Efficiency ratio (G) (I) (K) 44.06 % 44.80 % 45.71 % 46.10 % 46.87 % 44.85 % 49.25 %
Liquidity and Capital Ratios
Equity to assets 20.00 % 19.78 % 19.39 % 18.80 % 18.35 % 20.00 % 18.35 %
Common equity tier 1 capital 17.53 % 17.10 % 16.92 % 16.42 % 15.84 % 17.53 % 15.84 %
Tier 1 risk-based capital 17.53 % 17.10 % 16.92 % 16.42 % 15.84 % 17.53 % 15.84 %
Total risk-based capital 18.78 % 18.35 % 18.17 % 17.67 % 17.09 % 18.78 % 17.09 %
Tier 1 leverage capital 11.90 % 11.62 % 11.20 % 10.82 % 10.52 % 11.90 % 10.52 %
Period end tangible equity to period end tangible assets (G) 11.81 % 11.58 % 11.23 % 10.75 % 10.36 % 11.81 % 10.36 %
Other Data
Weighted-average shares used in computing earnings per common share
Basic 95,093 95,277 95,266 95,264 95,261 95,211 94,912
Diluted 95,093 95,277 95,266 95,264 95,261 95,211 94,912
Period end shares outstanding 94,993 95,277 95,258 95,275 95,261 94,993 95,261
Cash dividends paid per common share $ 0.58 $ 0.58 $ 0.58 $ 0.58 $ 0.56 $ 1.74 $ 1.68
Book value per common share $ 80.69 $ 79.76 $ 78.91 $ 78.07 $ 77.27 $ 80.69 $ 77.27
Tangible book value per common share (G) $ 43.23 $ 42.38 $ 41.48 $ 40.61 $ 39.75 $ 43.23 $ 39.75
Common Stock Market Price
High $ 75.44 $ 74.56 $ 82.75 $ 86.76 $ 74.87 $ 82.75 $ 74.87
Low $ 64.27 $ 61.57 $ 68.96 $ 68.94 $ 58.66 $ 61.57 $ 57.16
Period end closing price $ 66.35 $ 70.24 $ 71.37 $ 75.35 $ 72.07 $ 66.35 $ 72.07
Employees – FTE (excluding overtime) 3,937 3,921 3,898 3,916 3,896 3,937 3,896
Number of banking centers 283 283 284 283 287 283 287

(D) Includes purchase accounting adjustments for the periods presented as follows:

Three Months Ended Year-to-Date
Sep 30,<br><br>2025 Jun 30,<br><br>2025 Mar 31,<br><br>2025 Dec 31,<br><br>2024 Sep 30,<br><br>2024 Sep 30,<br><br>2025 Sep 30,<br><br>2024
Loan discount accretion
Non-PCD $2,242 $2,486 $2,615 $2,761 $3,616 $7,343 $9,725
PCD $613 $638 $677 $850 $1,212 $1,928 $4,154
Securities net accretion $395 $409 $705 $528 $555 $1,509 $1,680
Time deposits amortization $(1) $(2) $(9) $(21) $(40) $(12) $(133)

(E) Using effective tax rate of 21.9%, 21.5%, 21.7%, 21.7% and 21.6% for the three months ended September 30, 2025, June 30, 2025, March 31, 2025, December 31, 2024 and September 30, 2024, respectively, and 21.7% and 21.8% for the nine months ended September 30, 2025 and 2024, respectively.

(F) Interim periods annualized.

(G) Refer to the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of this non-GAAP financial measure to the nearest GAAP financial measure.

(H) Net interest margin for all periods presented is based on average balances on an actual 365-day or 366-day basis.

(I) Calculated by dividing total noninterest expense, excluding credit loss provisions, by net interest income plus noninterest income, excluding net gains and losses on the sale, write-down or write-up of assets and securities. Additionally, taxes are not part of this calculation.

(J) For calculations of the annualized returns on average assets, average common equity and average tangible common equity excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax refer to the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of this non-GAAP financial measure to the nearest GAAP financial measure.

(K) For calculations of the efficiency ratio excluding merger related expenses and FDIC special assessment refer to the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of these non-GAAP financial measures to the nearest respective GAAP financial measures.

Page 12

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

YIELD ANALYSIS Three Months Ended
Sep 30, 2025 Jun 30, 2025 Sep 30, 2024
Average<br>Balance Interest<br>Earned/<br>Interest<br>Paid Average<br>Yield/<br>Rate (L) Average<br>Balance Interest<br>Earned/<br>Interest<br>Paid Average<br>Yield/<br>Rate (L) Average<br>Balance Interest<br>Earned/<br>Interest<br>Paid Average<br>Yield/<br>Rate (L)
Interest-earning assets:
Loans held for sale $ 8,371 $ 140 6.64% $ 9,813 $ 166 6.79% $ 7,913 $ 137 6.89%
Loans held for investment 20,851,896 309,949 5.90% 20,907,400 306,671 5.88% 21,107,139 316,939 5.97%
Loans held for investment - Warehouse Purchase Program 1,217,579 19,356 6.31% 1,179,307 18,653 6.34% 1,114,681 20,375 7.27%
Total loans 22,077,846 329,445 5.92% 22,096,520 325,490 5.91% 22,229,733 337,451 6.04%
Investment securities 10,530,807 58,207 2.19% (M) 10,867,856 57,836 2.13% (M) 11,612,193 59,617 2.04% (M)
Federal funds sold and other earning assets 934,318 10,455 4.44% 841,933 9,438 4.50% 1,531,788 20,835 5.41%
Total interest-earning assets 33,542,971 398,107 4.71% 33,806,309 392,764 4.66% 35,373,714 417,903 4.70%
Allowance for credit losses on loans (343,872 ) (348,310 ) (358,237 )
Noninterest-earning assets 4,930,764 4,933,215 4,873,725
Total assets $ 38,129,863 $ 38,391,214 $ 39,889,202
Interest-bearing liabilities:
Interest-bearing demand deposits $ 4,656,452 $ 8,951 0.76% $ 4,807,864 $ 8,859 0.74% $ 4,774,975 $ 9,251 0.77%
Savings and money market deposits 8,977,585 46,934 2.07% 8,944,897 45,796 2.05% 8,908,315 49,824 2.23%
Certificates and other time deposits 4,422,996 40,080 3.60% 4,366,510 39,135 3.59% 4,564,232 48,683 4.24%
Other borrowings 2,480,435 27,613 4.42% 2,717,583 30,101 4.44% 3,900,000 46,792 4.77%
Securities sold under repurchase agreements 187,462 1,094 2.32% 194,577 1,151 2.37% 242,813 1,662 2.72%
Total interest-bearing liabilities 20,724,930 124,672 2.39% (N) 21,031,431 125,042 2.38% (N) 22,390,335 156,212 2.78% (N)
Noninterest-bearing liabilities:
Noninterest-bearing demand deposits 9,451,153 9,508,845 9,680,785
Allowance for credit losses on off-balance sheet credit exposures 37,646 37,646 37,646
Other liabilities 258,156 227,002 433,171
Total liabilities 30,471,885 30,804,924 32,541,937
Shareholders' equity 7,657,978 7,586,290 7,347,265
Total liabilities and shareholders' equity $ 38,129,863 $ 38,391,214 $ 39,889,202
Net interest income and margin $ 273,435 3.23% $ 267,722 3.18% $ 261,691 2.94%
Non-GAAP to GAAP reconciliation:
Tax equivalent adjustment 807 574 808
Net interest income and margin<br>     (tax equivalent basis) $ 274,242 3.24% $ 268,296 3.18% $ 262,499 2.95%

(L) Annualized and based on an actual 365-day or 366-day basis.

(M) Yield on securities was impacted by net premium amortization of $2,877, $4,926, and $5,574 for the three months ended September 30, 2025, June 30, 2025 and September 30, 2024, respectively.

(N) Total cost of funds, including noninterest bearing deposits, was 1.64%, 1.64% and 1.94% for the three months ended September 30, 2025, June 30, 2025 and September 30, 2024, respectively.

Page 13

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

YIELD ANALYSIS Year-to-Date
Sep 30, 2025 Sep 30, 2024
Average<br>Balance Interest<br>Earned/<br>Interest<br>Paid Average<br>Yield/<br>Rate (O) Average<br>Balance Interest<br>Earned/<br>Interest<br>Paid Average<br>Yield/<br>Rate (O)
Interest-earning assets:
Loans held for sale $ 8,588 $ 433 6.74% $ 7,278 $ 378 6.94%
Loans held for investment 20,905,781 921,688 5.89% 21,312,440 928,973 5.82%
Loans held for investment - Warehouse Purchase Program 1,092,241 51,837 6.35% 918,172 50,756 7.38%
Total loans 22,006,610 973,958 5.92% 22,237,890 980,107 5.89%
Investment securities 10,803,572 173,929 2.15% (P) 12,161,391 188,466 2.07% (P)
Federal funds sold and other earning assets 1,071,293 35,789 4.47% 1,153,335 44,195 5.12%
Total interest-earning assets 33,881,475 1,183,676 4.67% 35,552,616 1,212,768 4.56%
Allowance for credit losses on loans (347,607 ) (341,659 )
Noninterest-earning assets 4,955,209 4,823,938
Total assets $ 38,489,077 $ 40,034,895
Interest-bearing liabilities:
Interest-bearing demand deposits $ 4,894,289 $ 26,829 0.73% $ 4,947,514 $ 26,807 0.72%
Savings and money market deposits 8,976,481 138,375 2.06% 9,060,992 147,228 2.17%
Certificates and other time deposits 4,405,329 120,148 3.65% 4,356,700 132,539 4.06%
Other borrowings 2,657,143 88,206 4.44% 3,960,821 142,020 4.79%
Securities sold under repurchase agreements 199,883 3,579 2.39% 265,878 5,453 2.74%
Total interest-bearing liabilities 21,133,125 377,137 2.39% (Q) 22,591,905 454,047 2.68% (Q)
Noninterest-bearing liabilities:
Noninterest-bearing demand deposits 9,487,984 9,759,927
Allowance for credit losses on off-balance sheet credit exposures 37,646 36,994
Other liabilities 246,408 372,060
Total liabilities 30,905,163 32,760,886
Shareholders' equity 7,583,914 7,274,009
Total liabilities and shareholders' equity $ 38,489,077 $ 40,034,895
Net interest income and margin $ 806,539 3.18% $ 758,721 2.85%
Non-GAAP to GAAP reconciliation:
Tax equivalent adjustment 1,671 2,416
Net interest income and margin (tax equivalent basis) $ 808,210 3.19% $ 761,137 2.86%

(O) Based on an actual 365-day or 366-day basis.

(P) Yield on securities was impacted by net premium amortization of $12,830 and $17,227 for the nine months ended September 30, 2025 and 2024, respectively.

(Q) Total cost of funds, including noninterest bearing deposits, was 1.65% and 1.87% for the nine months ended September 30, 2025 and 2024, respectively.

Page 14

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

Three Months Ended
Sep 30, 2025 Jun 30, 2025 Mar 31, 2025 Dec 31, 2024 Sep 30, 2024
YIELD TREND (R)
Interest-Earning Assets:
Loans held for sale 6.64 % 6.79 % 6.80 % 6.68 % 6.89 %
Loans held for investment 5.90 % 5.88 % 5.90 % 5.93 % 5.97 %
Loans held for investment - Warehouse Purchase Program 6.31 % 6.34 % 6.40 % 6.66 % 7.27 %
Total loans 5.92 % 5.91 % 5.92 % 5.97 % 6.04 %
Investment securities (S) 2.19 % 2.13 % 2.13 % 2.06 % 2.04 %
Federal funds sold and other earning assets 4.44 % 4.50 % 4.47 % 4.80 % 5.41 %
Total interest-earning assets 4.71 % 4.66 % 4.64 % 4.66 % 4.70 %
Interest-Bearing Liabilities:
Interest-bearing demand deposits 0.76 % 0.74 % 0.70 % 0.70 % 0.77 %
Savings and money market deposits 2.07 % 2.05 % 2.06 % 2.10 % 2.23 %
Certificates and other time deposits 3.60 % 3.59 % 3.75 % 4.06 % 4.24 %
Other borrowings 4.42 % 4.44 % 4.45 % 4.73 % 4.77 %
Securities sold under repurchase agreements 2.32 % 2.37 % 2.48 % 2.58 % 2.72 %
Total interest-bearing liabilities 2.39 % 2.38 % 2.39 % 2.60 % 2.78 %
Net Interest Margin 3.23 % 3.18 % 3.14 % 3.04 % 2.94 %
Net Interest Margin (tax equivalent) 3.24 % 3.18 % 3.14 % 3.05 % 2.95 %

(R) Annualized and based on average balances on an actual 365-day or 366-day basis.

(S) Yield on securities was impacted by net premium amortization of $2,877, $4,926, $5,027, $5,609 and $5,574 for the three months ended September 30, 2025, June 30, 2025, March 31, 2025, December 31, 2024 and September 30, 2024, respectively.

Page 15

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

Three Months Ended
Sep 30, 2025 Jun 30, 2025 Mar 31, 2025 Dec 31, 2024 Sep 30, 2024
Balance Sheet Averages
Loans held for sale $ 8,371 $ 9,813 $ 7,570 $ 8,571 $ 7,913
Loans held for investment 20,851,896 20,907,400 20,959,226 21,038,694 21,107,139
Loans held for investment - Warehouse Purchase Program 1,217,579 1,179,307 876,086 1,137,113 1,114,681
Total loans 22,077,846 22,096,520 21,842,882 22,184,378 22,229,733
Investment securities 10,530,807 10,867,856 11,017,400 11,265,535 11,612,193
Federal funds sold and other earning assets 934,318 841,933 1,443,220 1,628,050 1,531,788
Total interest-earning assets 33,542,971 33,806,309 34,303,502 35,077,963 35,373,714
Allowance for credit losses on loans (343,872 ) (348,310 ) (350,715 ) (353,560 ) (358,237 )
Cash and due from banks 291,809 294,379 326,066 317,420 304,911
Goodwill 3,503,127 3,503,127 3,503,128 3,505,030 3,504,300
Core deposit intangibles, net 56,956 60,739 64,293 68,167 72,330
Other real estate 11,533 8,749 7,105 6,778 5,339
Fixed assets, net 377,680 374,486 374,448 373,561 375,626
Other assets 689,659 691,735 729,251 632,040 611,219
Total assets $ 38,129,863 $ 38,391,214 $ 38,957,078 $ 39,627,399 $ 39,889,202
Noninterest-bearing deposits $ 9,451,153 $ 9,508,845 $ 9,504,540 $ 9,829,912 $ 9,680,785
Interest-bearing demand deposits 4,656,452 4,807,864 5,224,796 4,845,174 4,774,975
Savings and money market deposits 8,977,585 8,944,897 9,007,286 8,915,410 8,908,315
Certificates and other time deposits 4,422,996 4,366,510 4,426,521 4,552,445 4,564,232
Total deposits 27,508,186 27,628,116 28,163,143 28,142,941 27,928,307
Other borrowings 2,480,435 2,717,583 2,776,667 3,332,609 3,900,000
Securities sold under repurchase agreements 187,462 194,577 217,945 231,240 242,813
Allowance for credit losses on off-balance sheet credit exposures 37,646 37,646 37,646 37,646 37,646
Other liabilities 258,156 227,002 255,876 454,298 433,171
Shareholders' equity 7,657,978 7,586,290 7,505,801 7,428,665 7,347,265
Total liabilities and equity $ 38,129,863 $ 38,391,214 $ 38,957,078 $ 39,627,399 $ 39,889,202

Page 16

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

Sep 30, 2025 Jun 30, 2025 Mar 31, 2025 Dec 31, 2024 Sep 30, 2024
Period End Balances
Loan Portfolio
Commercial and industrial $ 1,879,282 8.5 % $ 1,897,117 8.6 % $ 1,915,124 8.7 % $ 1,962,111 8.8 % $ 1,970,844 8.8 %
Warehouse purchase program 1,278,178 5.8 % 1,287,440 5.8 % 1,057,893 4.8 % 1,080,903 4.9 % 1,228,706 5.5 %
Construction, land development and other land loans 2,865,279 13.0 % 2,873,238 12.9 % 2,845,082 13.0 % 2,859,281 12.9 % 2,814,521 12.6 %
1-4 family residential 7,461,900 33.9 % 7,530,816 33.9 % 7,576,350 34.5 % 7,581,450 34.2 % 7,557,858 33.8 %
Home equity 848,740 3.9 % 869,370 3.9 % 896,529 4.1 % 906,139 4.1 % 919,676 4.1 %
Commercial real estate (includes multi-family residential) 5,796,937 26.3 % 5,827,645 26.3 % 5,783,410 26.3 % 5,800,985 26.2 % 5,869,687 26.2 %
Agriculture (includes farmland) 1,019,589 4.6 % 1,029,250 4.6 % 1,013,960 4.6 % 1,033,546 4.7 % 1,033,224 4.6 %
Consumer and other 366,027 1.7 % 368,747 1.7 % 378,821 1.7 % 378,817 1.7 % 413,548 1.8 %
Energy 511,837 2.3 % 513,765 2.3 % 510,401 2.3 % 545,977 2.5 % 572,788 2.6 %
Total loans $ 22,027,769 $ 22,197,388 $ 21,977,570 $ 22,149,209 $ 22,380,852
Deposit Types
Noninterest-bearing DDA $ 9,522,028 34.3 % $ 9,426,657 34.3 % $ 9,675,915 34.5 % $ 9,798,438 34.5 % $ 9,811,361 34.9 %
Interest-bearing DDA 4,766,146 17.2 % 4,708,251 17.1 % 4,931,769 17.6 % 5,182,035 18.3 % 4,800,758 17.1 %
Money market 6,402,591 23.0 % 6,302,770 23.0 % 6,339,509 22.6 % 6,229,022 21.9 % 6,166,792 22.0 %
Savings 2,616,196 9.4 % 2,667,859 9.7 % 2,703,736 9.7 % 2,685,496 9.5 % 2,707,982 9.6 %
Certificates and other time deposits 4,475,133 16.1 % 4,367,874 15.9 % 4,375,870 15.6 % 4,486,347 15.8 % 4,600,718 16.4 %
Total deposits $ 27,782,094 $ 27,473,411 $ 28,026,799 $ 28,381,338 $ 28,087,611
Loan to Deposit Ratio 79.3 % 80.8 % 78.4 % 78.0 % 79.7 %

Page 17

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

Construction Loans

Sep 30, 2025 Jun 30, 2025 Mar 31, 2025 Dec 31, 2024 Sep 30, 2024
Single family residential construction $ 665,194 23.2 % $ 696,569 24.2 % $ 727,417 25.6 % $ 778,067 27.2 % $ 836,571 29.7 %
Land development 248,616 8.7 % 227,254 7.9 % 225,784 7.9 % 260,158 9.1 % 256,571 9.1 %
Raw land 230,021 8.0 % 248,380 8.7 % 261,918 9.2 % 278,892 9.7 % 263,411 9.4 %
Residential lots 203,396 7.1 % 217,835 7.6 % 219,115 7.7 % 209,850 7.3 % 217,920 7.7 %
Commercial lots 59,853 2.1 % 55,176 1.9 % 56,343 2.0 % 59,044 2.1 % 58,472 2.1 %
Commercial construction and other 1,459,255 50.9 % 1,428,985 49.7 % 1,355,587 47.6 % 1,274,619 44.6 % 1,183,127 42.0 %
Net unaccreted discount (1,056 ) (961 ) (1,082 ) (1,349 ) (1,551 )
Total construction loans $ 2,865,279 $ 2,873,238 $ 2,845,082 $ 2,859,281 $ 2,814,521

Non-Owner Occupied Commercial Real Estate Loans by Metropolitan Statistical Area (MSA) as of September 30, 2025

Houston Dallas Austin OK City Tulsa Other (T) Total
Collateral Type
Shopping center/retail $ 328,842 $ 230,333 $ 122,499 $ 15,103 $ 12,002 $ 319,570 $ 1,028,349
Commercial and industrial buildings 179,377 103,862 24,433 32,680 12,026 256,858 609,236
Office buildings 99,991 280,699 68,563 43,802 4,224 94,839 592,118
Medical buildings 105,993 16,818 1,642 41,745 26,479 64,595 257,272
Apartment buildings 107,677 127,757 64,215 11,115 13,508 209,436 533,708
Hotel 106,613 116,016 30,162 13,349 176,330 442,470
Other 170,647 59,768 19,364 5,654 6,868 93,779 356,080
Total $ 1,099,140 $ 935,253 $ 330,878 $ 163,448 $ 75,107 $ 1,215,407 $ 3,819,233 (U)

Acquired Loans

Non-PCD Loans PCD Loans Total Acquired Loans
Balance at <br>Acquisition <br>Date Balance at<br>Jun 30,<br>2025 Balance at<br>Sep 30,<br>2025 Balance at <br>Acquisition<br>Date Balance at<br>Jun 30,<br>2025 Balance at<br>Sep 30,<br>2025 Balance at <br>Acquisition<br>Date Balance at<br>Jun 30,<br>2025 Balance at<br>Sep 30,<br>2025
Loan marks:
Acquired banks (V) $ 388,625 $ 22,766 $ 20,406 $ 332,400 $ 6,075 $ 5,472 $ 721,025 $ 28,841 $ 25,878
Acquired portfolio loan balances:
Acquired banks (V) 14,323,981 1,786,602 1,609,115 1,376,673 387,143 350,644 15,700,654 (W) 2,173,745 1,959,759
Acquired portfolio loan balances less loan marks $ 13,935,356 $ 1,763,836 $ 1,588,709 $ 1,044,273 $ 381,068 $ 345,172 $ 14,979,629 $ 2,144,904 $ 1,933,881

(T) Includes other MSA and non-MSA regions.

(U) Represents a portion of total commercial real estate loans of $5.797 billion as of September 30, 2025.

(V) Includes Bank Arlington, American State Bank, Community National Bank, First Federal Bank Texas, Coppermark Bank, First Victoria National Bank, The F&M Bank & Trust Company, Tradition Bank, LegacyTexas Bank, FirstCapital Bank and Lone Star Bank.

(W) Actual principal balances acquired.

Page 18

Prosperity Bancshares, Inc.®

Financial Highlights (Unaudited)

(Dollars in thousands)

Three Months Ended Year-to-Date
Sep 30,<br>2025 Jun 30,<br>2025 Mar 31,<br>2025 Dec 31,<br>2024 Sep 30,<br>2024 Sep 30,<br>2025 Sep 30,<br>2024
Asset Quality
Nonaccrual loans $ 105,529 $ 102,031 $ 73,287 $ 73,647 $ 83,969 $ 105,529 $ 83,969
Accruing loans 90 or more days past due 268 576 91 2,189 20 268 20
Total nonperforming loans 105,797 102,607 73,378 75,836 83,989 105,797 83,989
Repossessed assets 16 6 29 4 177 16 177
Other real estate 13,750 7,874 8,012 5,701 5,757 13,750 5,757
Total nonperforming assets $ 119,563 $ 110,487 $ 81,419 $ 81,541 $ 89,923 $ 119,563 $ 89,923
Nonperforming assets:
Commercial and industrial (includes energy) $ 27,880 $ 27,680 $ 8,966 $ 10,080 $ 13,642 $ 27,880 $ 13,642
Construction, land development and other land loans 583 1,859 1,952 4,481 4,053 583 4,053
1-4 family residential (includes home equity) 57,241 50,501 42,481 44,824 36,660 57,241 36,660
Commercial real estate (includes multi-family residential) 11,471 12,865 12,257 18,861 32,803 11,471 32,803
Agriculture (includes farmland) 17,080 17,547 15,725 3,208 2,686 17,080 2,686
Consumer and other 5,308 35 38 87 79 5,308 79
Total $ 119,563 $ 110,487 $ 81,419 $ 81,541 $ 89,923 $ 119,563 $ 89,923
Number of loans/properties 424 392 363 368 346 424 346
Allowance for credit losses on loans $ 339,626 $ 346,084 $ 349,101 $ 351,805 $ 354,397 $ 339,626 $ 354,397
Net charge-offs (recoveries):
Commercial and industrial (includes energy) $ 3,341 $ 1,044 $ 330 $ 405 $ 3,309 $ 4,715 $ 6,369
Construction, land development and other land loans 34 (3 ) (156 ) 294 378 (125 ) 485
1-4 family residential (includes home equity) 853 342 1,051 180 409 2,246 1,291
Commercial real estate (includes multi-family residential) 1,015 55 178 362 258 1,248 (140 )
Agriculture (includes farmland) (40 ) (14 ) 5 (116 ) (54 ) 121
Consumer and other 1,255 1,593 1,301 1,346 1,217 4,149 3,840
Total $ 6,458 $ 3,017 $ 2,704 $ 2,592 $ 5,455 $ 12,179 $ 11,966
Asset Quality Ratios
Nonperforming assets to average interest-earning assets 0.36 % 0.33 % 0.24 % 0.23 % 0.25 % 0.35 % 0.25 %
Nonperforming assets to loans and other real estate 0.54 % 0.50 % 0.37 % 0.37 % 0.40 % 0.54 % 0.40 %
Net charge-offs to average loans (annualized) 0.12 % 0.05 % 0.05 % 0.05 % 0.10 % 0.07 % 0.07 %
Allowance for credit losses on loans to total loans 1.54 % 1.56 % 1.59 % 1.59 % 1.58 % 1.54 % 1.58 %
Allowance for credit losses on loans to total loans, excluding Warehouse Purchase Program loans (G) 1.64 % 1.66 % 1.67 % 1.67 % 1.68 % 1.64 % 1.68 %

Page 19

Prosperity Bancshares, Inc.®

Notes to Selected Financial Data (Unaudited)

(Dollars and share amounts in thousands, except per share data)

NOTES TO SELECTED FINANCIAL DATA

Prosperity’s management uses certain non-GAAP (generally accepted accounting principles) financial measures to evaluate its performance. Specifically, for internal planning and forecasting purposes, Prosperity reviews each of diluted earnings per share, return on average assets, return on average common equity, and return on average tangible common equity, in each case excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax; return on average tangible common equity; tangible book value per share; the tangible equity to tangible assets ratio; allowance for credit losses to total loans excluding Warehouse Purchase Program loans; the efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities; and the efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities, merger related expenses and FDIC special assessment. In addition, due to the application of purchase accounting, Prosperity uses certain non-GAAP financial measures and ratios that exclude the impact of these items to evaluate its allowance for credit losses to total loans (excluding Warehouse Purchase Program loans). Prosperity has included information below relating to these non-GAAP financial measures for the applicable periods presented.

Three Months Ended Year-to-Date
Sep 30,<br>2025 Jun 30,<br>2025 Mar 31,<br>2025 Dec 31,<br>2024 Sep 30,<br>2024 Sep 30,<br>2025 Sep 30,<br>2024
Reconciliation of diluted earnings per share to diluted earnings per share excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax:
Diluted earnings per share (unadjusted) $ 1.45 $ 1.42 $ 1.37 $ 1.37 $ 1.34 $ 4.23 $ 3.68
Net income $ 137,556 $ 135,155 $ 130,225 $ 130,076 $ 127,282 $ 402,936 $ 349,310
Merger related provision for credit losses, net of tax(X) 7,162
Merger related expenses, net of tax(X) 49 50 49 3,511
FDIC special assessment, net of tax(X) 2,807
Net gain on sale or write-up of securities, net of tax(X) (177 ) (8,884 )
Net income excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax(X): $ 137,605 $ 135,155 $ 130,225 $ 130,076 $ 127,155 $ 402,985 $ 353,906
Weighted average diluted shares outstanding 95,093 95,277 95,266 95,264 95,261 95,211 94,912
Merger related provision for credit losses, net of tax, per diluted common share(X) $ $ $ $ $ $ $ 0.08
Merger related expenses, net of tax, per diluted common share(X) $ $ $ $ $ $ $ 0.04
FDIC special assessment, net of tax, per diluted common share(X) $ $ $ $ $ $ $ 0.03
Net gain on sale or write-up of securities, net of tax, per diluted common share(X) $ $ $ $ $ $ $ (0.09 )
Diluted earnings per share excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax:(X) $ 1.45 $ 1.42 $ 1.37 $ 1.37 $ 1.34 $ 4.23 $ 3.74
Reconciliation of return on average assets to return on average assets excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax:
Return on average assets (unadjusted) 1.44 % 1.41 % 1.34 % 1.31 % 1.28 % 1.40 % 1.16 %
Net income excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax(X): $ 137,605 $ 135,155 $ 130,225 $ 130,076 $ 127,155 $ 402,985 $ 353,906
Average total assets $ 38,129,863 $ 38,391,214 $ 38,957,078 $ 39,627,399 $ 39,889,202 $ 38,489,077 $ 40,034,895
Return on average assets excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax (F) (X) 1.44 % 1.41 % 1.34 % 1.31 % 1.28 % 1.40 % 1.18 %

(X) Calculated assuming a federal tax rate of 21.0%.

Page 20

Three Months Ended Year-to-Date
Sep 30,<br>2025 Jun 30,<br>2025 Mar 31,<br>2025 Dec 31,<br>2024 Sep 30,<br>2024 Sep 30,<br>2025 Sep 30,<br>2024
Reconciliation of return on average common equity to return on average common equity excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax:
Return on average common equity (unadjusted) 7.18 % 7.13 % 6.94 % 7.00 % 6.93 % 7.08 % 6.40 %
Net income excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax(X): $ 137,605 $ 135,155 $ 130,225 $ 130,076 $ 127,155 $ 402,985 $ 353,906
Average shareholders' equity $ 7,657,978 $ 7,586,290 $ 7,505,801 $ 7,428,665 $ 7,347,265 $ 7,583,914 $ 7,274,009
Return on average common equity excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax (F) (X) 7.19 % 7.13 % 6.94 % 7.00 % 6.92 % 7.08 % 6.49 %
Reconciliation of return on average common equity to return on average tangible common equity:
Net income $ 137,556 $ 135,155 $ 130,225 $ 130,076 $ 127,282 $ 402,936 $ 349,310
Average shareholders' equity $ 7,657,978 $ 7,586,290 $ 7,505,801 $ 7,428,665 $ 7,347,265 $ 7,583,914 $ 7,274,009
Less: Average goodwill and other intangible assets (3,560,083 ) (3,563,866 ) (3,567,421 ) (3,573,197 ) (3,576,630 ) (3,563,763 ) (3,526,501 )
Average tangible shareholders’ equity $ 4,097,895 $ 4,022,424 $ 3,938,380 $ 3,855,468 $ 3,770,635 $ 4,020,151 $ 3,747,508
Return on average tangible common equity (F) 13.43 % 13.44 % 13.23 % 13.50 % 13.50 % 13.36 % 12.43 %
Reconciliation of return on average common equity to return on average tangible common equity excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, and FDIC special assessment, net of tax:
Net income excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax(X): $ 137,605 $ 135,155 $ 130,225 $ 130,076 $ 127,155 $ 402,985 $ 353,906
Average shareholders' equity $ 7,657,978 $ 7,586,290 $ 7,505,801 $ 7,428,665 $ 7,347,265 $ 7,583,914 $ 7,274,009
Less: Average goodwill and other intangible assets (3,560,083 ) (3,563,866 ) (3,567,421 ) (3,573,197 ) (3,576,630 ) (3,563,763 ) (3,526,501 )
Average tangible shareholders’ equity $ 4,097,895 $ 4,022,424 $ 3,938,380 $ 3,855,468 $ 3,770,635 $ 4,020,151 $ 3,747,508
Return on average tangible common equity excluding merger related provision for credit losses, net of tax, merger related expenses, net of tax, FDIC special assessment, net of tax, and net gain on sale or write-up of securities, net of tax (F) (X) 13.43 % 13.44 % 13.23 % 13.50 % 13.49 % 13.37 % 12.59 %
Reconciliation of book value per share to tangible book value per share:
Shareholders’ equity $ 7,664,938 $ 7,599,736 $ 7,517,061 $ 7,438,495 $ 7,361,249 $ 7,664,938 $ 7,361,249
Less: Goodwill and other intangible assets (3,558,321 ) (3,561,923 ) (3,565,533 ) (3,569,176 ) (3,574,566 ) (3,558,321 ) (3,574,566 )
Tangible shareholders’ equity $ 4,106,617 $ 4,037,813 $ 3,951,528 $ 3,869,319 $ 3,786,683 $ 4,106,617 $ 3,786,683
Period end shares outstanding 94,993 95,277 95,258 95,275 95,261 94,993 95,261
Tangible book value per share $ 43.23 $ 42.38 $ 41.48 $ 40.61 $ 39.75 $ 43.23 $ 39.75

Page 21

Three Months Ended Year-to-Date
Sep 30,<br>2025 Jun 30,<br>2025 Mar 31,<br>2025 Dec 31,<br>2024 Sep 30,<br>2024 Sep 30,<br>2025 Sep 30,<br>2024
Reconciliation of equity to assets ratio to period end tangible equity to period end tangible assets ratio:
Tangible shareholders’ equity $ 4,106,617 $ 4,037,813 $ 3,951,528 $ 3,869,319 $ 3,786,683 $ 4,106,617 $ 3,786,683
Total assets $ 38,330,469 $ 38,417,352 $ 38,764,675 $ 39,566,738 $ 40,115,320 $ 38,330,469 $ 40,115,320
Less: Goodwill and other intangible assets (3,558,321 ) (3,561,923 ) (3,565,533 ) (3,569,176 ) (3,574,566 ) (3,558,321 ) (3,574,566 )
Tangible assets $ 34,772,148 $ 34,855,429 $ 35,199,142 $ 35,997,562 $ 36,540,754 $ 34,772,148 $ 36,540,754
Period end tangible equity to period end tangible assets ratio 11.81 % 11.58 % 11.23 % 10.75 % 10.36 % 11.81 % 10.36 %
Reconciliation of allowance for credit losses to total loans to allowance for credit losses on loans to total loans excluding Warehouse Purchase Program:
Allowance for credit losses on loans $ 339,626 $ 346,084 $ 349,101 $ 351,805 $ 354,397 $ 339,626 $ 354,397
Total loans $ 22,027,769 $ 22,197,388 $ 21,977,570 $ 22,149,209 $ 22,380,852 $ 22,027,769 $ 22,380,852
Less: Warehouse Purchase Program loans (1,278,178 ) (1,287,440 ) (1,057,893 ) (1,080,903 ) (1,228,706 ) (1,278,178 ) (1,228,706 )
Total loans less Warehouse Purchase Program $ 20,749,591 $ 20,909,948 $ 20,919,677 $ 21,068,306 $ 21,152,146 $ 20,749,591 $ 21,152,146
Allowance for credit losses on loans to total loans excluding Warehouse Purchase Program 1.64 % 1.66 % 1.67 % 1.67 % 1.68 % 1.64 % 1.68 %
Reconciliation of efficiency ratio to efficiency ratio excluding net gains and losses on the sale, write-down or write-up of assets and securities:
Noninterest expense $ 138,635 $ 138,565 $ 140,301 $ 141,545 $ 140,338 $ 417,501 $ 429,028
Net interest income $ 273,435 $ 267,722 $ 265,382 $ 267,774 $ 261,691 $ 806,539 $ 758,721
Noninterest income 41,238 42,982 41,301 39,837 41,099 125,521 125,972
Less: net gain (loss) on sale or write-down of assets 3 1,414 (235 ) 584 3,178 1,182 2,240
Less: net gain on sale or write-up of securities 224 11,245
Noninterest income excluding net gains and losses on the sale, write-down or write-up of assets and securities 41,235 41,568 41,536 39,253 37,697 124,339 112,487
Total income excluding net gains and losses on the sale, write-down or write-up of assets and securities $ 314,670 $ 309,290 $ 306,918 $ 307,027 $ 299,388 $ 930,878 $ 871,208
Efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities 44.06 % 44.80 % 45.71 % 46.10 % 46.87 % 44.85 % 49.25 %
Reconciliation of efficiency ratio to efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities, merger related expenses and FDIC special assessment:
Noninterest expense $ 138,635 $ 138,565 $ 140,301 $ 141,545 $ 140,338 $ 417,501 $ 429,028
Less: merger related expenses 62 63 62 4,444
Less: FDIC special assessment 3,554
Noninterest expense excluding merger related expenses and FDIC special assessment $ 138,573 $ 138,565 $ 140,301 $ 141,545 $ 140,275 $ 417,439 $ 421,030
Net interest income $ 273,435 $ 267,722 $ 265,382 $ 267,774 $ 261,691 $ 806,539 $ 758,721
Noninterest income 41,238 42,982 41,301 39,837 41,099 125,521 125,972
Less: net gain (loss) on sale or write down of assets 3 1,414 (235 ) 584 3,178 1,182 2,240
Less: net gain on sale or write-up of securities 224 11,245
Noninterest income excluding net gains and losses on the sale, write-down or write-up of assets and securities 41,235 41,568 41,536 39,253 37,697 124,339 112,487
Total income excluding net gains and losses on the sale, write-down or write-up of assets and securities $ 314,670 $ 309,290 $ 306,918 $ 307,027 $ 299,388 $ 930,878 $ 871,208
Efficiency ratio, excluding net gains and losses on the sale, write-down or write-up of assets and securities, merger related expenses and FDIC special assessment 44.04 % 44.80 % 45.71 % 46.10 % 46.85 % 44.84 % 48.33 %

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