UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 15 CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934 OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934. Commission File Number: 000-21923 Commission File Number: 000-21923-02 WINTRUST FINANCIAL CORPORATION WINTRUST CAPITAL TRUST II (Exact name of co-registrant as specified in its charter) (Exact name of co-registrant as specified in its certificate of trust) 727 NORTH BANK LANE 727 NORTH BANK LANE LAKE FOREST, ILLINOIS 60045-1951 LAKE FOREST, ILLINOIS 60045-1951 (847) 615-4096 (847) 615-4096 (Address, including zip code, and telephone number, (Address, including zip code, and telephone number, including area code, of co-registrant's principal including area code, of co-registrant's principal executive offices) executive offices) 10.50% CUMULATIVE TRUST PREFERRED SECURITIES (AND THE GUARANTEE WITH RESPECT THERETO) OF WINTRUST CAPITAL TRUST II -------------------------------------------------------------------------------- (Title of each class of securities covered by this Form) COMMON STOCK, NO PAR VALUE PER SHARE, OF WINTRUST FINANCIAL CORPORATION 9.0% CUMULATIVE TRUST PREFERRED SECURITIES (AND GUARANTEE WITH RESPECT THERETO) OF WINTRUST CAPITAL TRUST I -------------------------------------------------------------------------------- (Titles of all other classes of securities for which a duty to file reports under section 13(a) or 15(d) remains) Please place an X in the box(es) to designate the appropriate rule provision(s) relied upon to terminate or suspend the duty to file reports: Rule 12g-4(a)(1)(i) |X| Rule 12h-3(b)(1)(i) |_| Rule 12g-4(a)(l)(ii) |_| Rule 12h-3(b)(1)(ii) |_| Rule 12g-4(a)(2)(i) |_| Rule 12h-3(b)(2)(i) |_| Rule 12g-4(a)(2)(ii) |_| Rule 12h-3(b)(2)(ii) |_| Rule 15d-6 |_| Approximate number of holders of record as of the certification or notice date: NONE Pursuant to the requirements of the Securities Exchange Act of 1934, Wintrust Financial Corporation and Wintrust Capital Trust II have each caused this certification/notice to be signed on its behalf by the undersigned duly authorized person. Date: August 16, 2005 By: /s/ David A. Dykstra ---------------------- ----------------------------------------- Name: David A. Dykstra Title: Senior Executive Vice President and Chief Operating Officer of Wintrust Financial Corporation, and Administrative Trustee of Wintrust Capital Trust II