Wintrust Financial Corp
A bank holding company based in Rosemont, Illinois, that runs a network of community banks offering checking, savings, loans, and mortgages through brands like Wintrust Mortgage. Founded by banker Ed Wehmer in 1991, its first branch opened as a Lake Forest storefront built on knowing customers by name. The quirky name wasn't a mission statement—founders picked "Wintrust" by throwing a dart at a book of company names.