Corporate Action, Amendments to Bylaws (Form 8-K)

Item 3.03. Material Modification to Rights of Security Holders.

On July 15, 2025, Wintrust Financial Corporation (the "Company") filed with the Secretary of the State of Illinois two Statements of Resolution (the "Modifications") relating to the Company's Amended and Restated Articles of Incorporation, as amended. The Modifications were filed solely to formally reflect that no shares of the Company's Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock, Series D, no par value per share (the "Series D Preferred Stock"), which series was created in 2015, and no shares of the Company's 6.875% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series E, no par value (the "Series E Preferred Stock"), which series was created in 2020, remain issued and outstanding. As a result of the Modifications, the shares formerly designated as the Series D Preferred Stock and the Series E Preferred Stock were returned to the status of authorized and unissued shares of the Company's preferred stock.

The only issued and outstanding series of preferred stock of the Company is the Company's 7.875% Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock, Series F, no par value (the "Series F Preferred Stock"), 17,000 shares of which were issued and sold in the Company's previously disclosed public offering of depositary shares, each representing a 1/1,000th interest in a share of Series F Preferred Stock, which was completed on May 22, 2025.

Copies of the Modifications are attached hereto as Exhibit 3.1 and Exhibit 3.2 and are incorporated herein by reference.

Item 5.03. Amendments to Articles of Incorporation or Bylaws; Change of Fiscal Year.

The information under Item 3.03 is incorporated herein by reference.