Simons Foundation Co-Founder, Mathematician and Investor Jim Simons Dies at 86

It is with great sadness that the Simons Foundation International announces the death of James Harris Simons, on May 10, 2024, at the age of 86, in New York City.

Jim (as he preferred to be called) was an award-winning mathematician, a legend in quantitative investing, and an inspired and generous philanthropist.

Together with his wife, Marilyn Simons, he gave billions of dollars to hundreds of philanthropic causes, particularly those supporting math and science research and education. In 1994, they established the Simons Foundation, which supports scientists and organizations worldwide in advancing the frontiers of research in mathematics and the basic sciences.

Jim was an active philanthropist until the end of his life, and his curiosity and lifelong passion for math and basic science were an inspiration to those around him. He was determined to make a meaningful difference in the level of support that mathematics and basic sciences received in the United States, notably by sponsoring projects that were important but unlikely to find funding elsewhere.

Jim frequently said that he went through three phases in his professional life: mathematician, investor and philanthropist. He previously chaired the math department at Stony Brook University in New York, and his mathematical breakthroughs during that time are now instrumental to fields such as string theory, topology and condensed matter physics.

In 1978, Jim founded what would become Renaissance Technologies, a hedge fund that pioneered quantitative trading and became one of the most profitable investment firms in history. He then turned his focus to making a difference in the world through the Simons Foundation, Simons Foundation International, Math for America and other philanthropic efforts.

“Jim was an exceptional leader who did transformative work in mathematics and developed a world-leading investment company,” says Simons Foundation International president David Spergel. “Together with Marilyn Simons, Jim had enormous impact in mathematics, basic science and our understanding of autism. Simons Foundation International will carry their vision for philanthropy into the future.”