Material Event (Form 8-K)

Item 8.01. Other Events.

On May 22, 2025, Wintrust Financial Corporation (the "Company") completed its previously disclosed public offering of 17,000,000 depositary shares (the "Depositary Shares"), each representing a 1/1,000th interest in a share of the Company's 7.875% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series F, no par value per share (the "Series F Preferred Stock"), with a liquidation preference of $25,000 per share (equivalent to $25.00 per Depositary Share). The Depositary Shares were issued pursuant to an Underwriting Agreement, dated as of May 8, 2025 (the "Underwriting Agreement"), between the Company and RBC Capital Markets, LLC, as representative of the several underwriters named in Schedule A thereto (the "Underwriters").

Holders of the Depositary Shares will be entitled to all proportional rights and preferences of the Series F Preferred Stock (including, dividend, voting, redemption and liquidation rights). Reference is hereby made to Item 3.03 of the Company's Current Report on Form 8-K filed on May 14, 2025 for a description of certain terms of the Series F Preferred Stock. Such description is qualified in its entirety by reference to the Company's Certificate of Designations relating to the Series F Preferred Stock, as filed with the Secretary of State of the State of Illinois on May 9, 2025, which is incorporated by reference herein as Exhibit 4.1 hereto.

In connection with the issuance of the Depositary Shares, on May 22, 2025, the Company entered into a Deposit Agreement (the "Deposit Agreement") with U.S. Bank Trust Company, National Association, as depositary of the Depositary Shares ("Depositary"), and the holders from time to time of the depositary receipts (the "Depositary Receipts") evidencing the Depositary Shares. On the same date, the 17,000 shares of Series F Preferred Stock underlying the Depositary Shares were deposited with the Depositary against the delivery of the Depositary Receipts pursuant to the Deposit Agreement. The Deposit Agreement is attached hereto as Exhibit 4.2 and the form of Depositary Receipt is attached hereto as Exhibit 4.3. The foregoing description of the Deposit Agreement and the Depositary Receipts are qualified in their entirety by reference to Exhibits 4.2 and 4.3, respectively, each of which is incorporated by reference herein.

The Depositary Shares were offered and sold pursuant to the Company's effective shelf registration statement on Form S-3 (File No. 333-271788), filed with the Securities and Exchange Commission (the "Commission") on May 9, 2023, and a prospectus supplement related to the Depositary Shares dated May 8, 2025 (filed with the Commission pursuant to Rule 424(b)(5) under the Securities Act of 1933, as amended).

In connection with the issuance of the Depositary Shares, Sidley Austin LLP provided the Company with the legal opinion filed as Exhibit 5.1 hereto, which is incorporated by reference herein.