James Harris "Jim" Simons (born 1938) is an American mathematician, hedge fund manager, and philanthropist. He is a code breaker and studies pattern recognition.Simons was a professor of mathematics at Stony Brook University and was also the former chair of the Mathematics Department at Stony Brook. In 1982, Simons founded Renaissance Technologies, a private hedge fund investment company based in New York with over $25 billion under management.