It is with great sadness that the Simons Foundation announces the death of its co-founder and chair emeritus, 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, Simons Foundation chair 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 active in the work of the Simons Foundation 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.

Over its 30-year history, the Simons Foundation’s work has led to breakthroughs in our understanding of autism, the origins of the universe, cellular biology and computational science. Jim and Marilyn’s giving continues to support the next generation of mathematicians and scientists at schools and universities in New York City and around the world.

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 president David Spergel. “Together with Marilyn Simons, the current Simons Foundation board chair, Jim created an organization that has already had enormous impact in mathematics, basic science and our understanding of autism. The Simons Foundation, an in-perpetuity foundation, will carry their vision for philanthropy into the future.”

Jim Simons is survived by his wife, three children, five grandchildren, a great-grandchild, and countless colleagues, friends and family who fondly recall his genuine curiosity and quick wit.

We know that many people have stories, messages and memories they would like to share about Jim. Please send them to observing@simonsfoundation.org.

Information on memorial services and other events honoring Jim’s life and legacy will be posted on the Simons Foundation website.

Source: Simons Foundation

Jim Simons was the greatest—an unbelievably great investor, philanthropist, and man of character. I and all who knew him will miss him.

— Ray Dalio (@RayDalio) May 10, 2024

RIP to an absolute legend and a good man. https://t.co/1cllcCqhK9

— Clifford Asness (@CliffordAsness) May 10, 2024

RIP Jim Simons
"I did a lot of math. I made a lot of money, and I gave almost all of it away. That's the story of my life." pic.twitter.com/uQ1j1oaEw6

— Mads Capital (@MadsCapital) May 10, 2024

Sad to hear about Simons’ death. Something not widely appreciated is his foundation runs the best general science news magazine in the world, @QuantaMagazine. It’s one of my favorite reads.

— Samuel Lee (@svrnco) May 10, 2024