Jim Simons, the billionaire investor, mathematician and philanthropist, died on Friday in New York City, according to his foundation, the Simons Foundation. Simons was 86 years old.

Using advanced computers, he went from M.I.T. professor to multibillionaire. His Medallion fund had 66 percent average annual returns for decades.

Jim Simons, a billionaire philanthropist who is known as one of the most successful hedge fund managers in history, has died at 86.