wintrust financial (wintrust) is a financial services holding company based in rosemont, illinois, with $21 billion in assets. wintrust engages in the business of providing traditional community banking services, wealth management services, commercial insurance premium financing, mortgage origination, short-term accounts receivable financing, and certain administrative services, such as data processing of payrolls, billing and treasury management services. wintrust provides community-oriented, personal and commercial banking services to customers located in the greater chicago, illinois and southern wisconsin metropolitan areas through its 15 wholly owned banking subsidiaries and more than 145 locations.