Ken Griffin, the founder of the hedge fund Citadel, is selling off his Chicago real estate as he moves to Florida.Vernon Yuen/Getty ImagesKen Griffin's Chicago penthouse — listed for $10 million less than he paid for it — has a buyer.A representative for Griffin said that his real-estate investments in Florida make up for the loss.Like Griffin, other wealthy people have left Chicago, due in part to hefty taxes and crime rates.Ken Griffin, the billionaire founder of the hedge fund Citadel, has found a buyer for his penthouse in Chicago.The six-bedroom apartment at the luxury condo building No.