James Simons, mathematician, philanthropist and hedge fund founder, has died

James “Jim” Simons, a renowned mathematician and pioneering investor who built a fortune on Wall Street and then became one of the nation’s biggest philanthropists, has died at age 86. The charitable foundation that Simons co-founded with his wife, Marilyn, announced that Simons died Friday in New York. Simons’ first career was in mathematics, for which he won acclaim. But in 1978, Simons traded academia for Wall Street. His hedge fund, Renaissance Technologies, pioneered the use of mathematical modeling — also known as quantitative trading — to pick stocks and other investments. The approach was wildly successful, helping Simons and his wife build over the years an estimated net worth of more than $30 billion.