UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D. C. 20549 FORM 13F FORM 13F COVER PAGE Report for Calendar Year or Quarter ended: September 30, 2003 Check here if Amendment ( ) ; Amendment Number: This Amendment(Check only one.)( )is a restatment. ( )adds new holdings entries. Institutional Investment Manager Filing this Report: Name: Wintrust Financial Corp. Address: 727 North Bank Lane Lake Forest, IL 60045 13F file number: The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form. Person Signing this Report on Behalf of Reporting Manager: Name: James F. Duca Title: Executive Vice President Phone: 1-800-621-4477 Signature, Place and Date of Signing: /S/ James F. Duca Lake Forest, IL November 14, 2003 Report Type (Check only one.): ( ) 13F HOLDINGS REPORT. ( ) 13F NOTICE. (x ) 13F COMBINATION REPORT List of other Managers Reporting for this Manager: Wayne Hummer Asset Mgmt Co Wayne Hummer Trust Company FORM 13F SUMMARY PAGE Report Summary: Number of Other Included Managers: 2 Form 13F Information Table Entry Total: 443 Form 13F Information Table Value Total: $690,790,000 List of Other Included Managers: Wayne Hummer Asset Management Company 28-05229 Wayne Hummer Trust Company