CNN  —  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. Simons, the founder of the hedge fund Renaissance Technologies, helped to pioneer quantitative investing, a market strategy that relies on mathematical and statistical models to identify investing opportunities. Later in life, Simons became a political donor and philanthropist. Simons had a love for math and numbers from an early age, according to his foundation’s website. Born in Newton, Massachusetts, in 1938, Simons earned a mathematics degree at the Massachusetts Institute of Technology and a doctorate in math from the University of California, Berkeley. “Mathematics was the only subject I liked,” Simons said in a 2015 interview for the Numberphile podcast. After a brief stint teaching at MIT and Harvard University, Simons joined the Institute for Defense Analyses in Princeton, New Jersey, working as a code breaker for the National Security Agency. According to his foundation, Simons was fired from the institute in 1968 due to his opposition to the Vietnam War. Simons then joined the faculty at Stony Brook University as the head of the school’s mathematics department. Simons left the academic world in the late ’70s, eventually founding Renaissance Technologies in 1982. “In looking at the patterns of prices, I could see that there was something we could study here and that there were ways to predict prices mathematically and statistically,” Simons said on the Numberphile podcast. “Gradually, we built models, and the models got better and better. Finally, the models replaced the fundamental stuff.” Simons’ computer models helped grow his hedge fund into a multi-billion-dollar business. Later in life, Simons devoted his time to philanthropy and became a large Democrat political donor. The Simons Foundation donates to autism research and provides grants for science and math education and research. Last year, Simons’ foundation donated $500 million to Stony Brook’s endowment, the largest unrestricted gift to an American university in history, according to the Simons Foundation. “I joined Stony Brook University in 1968 as chair of their Department of Mathematics,” Simons said at the time. “I knew then it was a top intellectual center with a serious commitment to research and innovation. But Stony Brook also gave me a chance to lead — and so it has been deeply rewarding to watch the university grow and flourish even more.”