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):

December 12, 2025 (December 10, 2025)

Stewart Information Services Corporation

(Exact name of registrant as specified in its charter)

(Registrant’s Telephone Number, Including Area Code) (713) 625-8100

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 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

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. ¨

On December 10, 2025, Stewart Information Services Corporation (the “Company”) entered into an underwriting agreement (the “Underwriting Agreement”), between the Company and Goldman Sachs & Co. LLC, as representative of the several underwriters listed on Schedule I thereto (the “Underwriters”), pursuant to which the Company agreed to issue and sell to the Underwriters 1,900,000 shares of common stock, par value $1.00 (“Common Stock”), in a registered public offering (the “Offering”) pursuant to an effective shelf registration statement on Form S-3 (Registration File No. 333-292051) (the “Shelf Registration Statement”). Pursuant to the Underwriting Agreement, the Company granted the Underwriters an option to purchase an additional 285,000 shares of Common Stock (the “Option”). On December 11, 2025, the Underwriters exercised in full the Option. The description of the Underwriting Agreement contained herein is qualified in its entirety by reference to the Underwriting Agreement, a copy of which is included as Exhibit 1.1 to this Current Report on Form 8-K and is incorporated herein by reference. A specimen certificate for the Common Stock is included as Exhibit 4.1 to this Current Report on Form 8-K and is also incorporated herein by reference.

On December 12, 2025, the Company closed the Offering, including the shares of Common Stock issuable pursuant to the Option.

On December 10, 2025, the Company’s wholly owned subsidiary, SISCO Holdings, LLC, completed its previously announced acquisition of the mortgage services of Mortgage Contracting Services, a property preservation services provider, for a cash purchase price of $330 million.

The Offering was made pursuant to the Shelf Registration Statement. The legal opinion of Davis Polk & Wardwell LLP relating to the Common Stock sold pursuant to the Underwriting Agreement is filed as Exhibit 5.1 to this Current Report on Form 8-K.

SIGNATURE

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 thereunto duly authorized.

Date: December 12, 2025