Prosperity Bancshares Inc. filed SEC Form 8-K: Other Events, Financial Statements and Exhibits

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): February 2, 2026

PROSPERITY BANCSHARES, INC.

(Exact name of registrant as specified in its charter)

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):

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

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 8.01 Other Events.

On February 2, 2026, Prosperity Bancshares, Inc. (“Prosperity”) issued a press release announcing the closing of the acquisition by Prosperity of Southwest Bancshares, Inc. (“Southwest”). Pursuant to the Agreement and Plan of Merger, dated as of September 30, 2025, by and between Prosperity and Southwest, Southwest merged with and into Prosperity, with Prosperity continuing as the surviving corporation (the “Merger”), and following the Merger, Texas Partners Bank, a Texas banking association and a wholly-owned subsidiary of Southwest, merged with and into Prosperity Bank, a Texas banking association and a wholly-owned subsidiary of Prosperity, with Prosperity Bank continuing as the surviving bank. A copy of Prosperity's press release is attached hereto as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

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.