James Simons, mathematician turned billionaire hedge fund founder and philanthropist, dies at 86

James Harris Simons, the Stony Brook University mathematician who founded a successful hedge fund in East Setauket and then donated hundreds of millions of dollars to the university, died Friday morning, his family foundation announced.

Simons was 86 and died in New York City, the foundation said on Friday. It did not disclose the cause of death.

Simons led the math department at Stony Brook from 1968 to 1978 before starting what would become Renaissance Technologies LLC, one of the most profitable investment firms in history, according to financial experts.

“Jim had a passion for Stony Brook University, Brookhaven National Laboratory and Cold Spring Harbor Laboratory — and [believed] that if they collaborated, they could do some really good things,” said Kevin Law, chairman of the Stony Brook Council and former CEO of the Long Island Association business group.

“Jim had a huge impact on our region, and I think his death is a big loss for Long Island,” Law said in an interview.

Simons used his math skills to pioneer quantitative investing at Renaissance, with offices in East Setauket and Manhattan. The firm hired scientists, mathematicians and statisticians to develop computer models and artificial intelligence for the buying and selling of stocks decades before other investors.

In 1994, with his wife, Marilyn, Simons established the Simons Foundation, which backs many causes with a focus on math and scientific research and education. In recognition of the Simons' generosity and that of Renaissance, Stony Brook named its medical school after the investment firm in 2018.

Last year, the Simons Foundation donated $500 million to Stony Brook, the largest charitable gift to a university without restrictions on how the money is to be spent, in U.S. history.

“I just love Stony Brook — it’s just a wonderful institution in every respect,” Simons said in June at a ceremony announcing the donation. “It has been deeply rewarding to watch the university grow and flourish even more.”

Simons was born on April 25, 1938, in Newton, Massachusetts, the son of a shoe factory owner.

He earned a bachelor’s degree in mathematics at the Massachusetts Institute of Technology in 1958 and a doctorate in mathematics from the University of California, Berkeley, in 1961.

Prior to coming to Long Island, Simons briefly taught math at MIT and Harvard University before working as a codebreaker at the Institute for Defense Analyses in Princeton, New Jersey during the Vietnam War. He left the latter job because he opposed the war, according to his family foundation.

While at Stony Brook, Simons won the prestigious Oswald Veblen Prize in Geometry from the American Mathematical Society for work in differential geometry and co-authoring a theorem about spheres and other curved surfaces.

“Jim was genuinely interested in research; he was insightful and had a quick wit,” Bruce Stillman, CEO and president of Cold Spring Harbor Laboratory, said on Friday. The lab is supported by the Simons Foundation and Marilyn Simons leads the lab’s board of trustees.

He began investing while still teaching college students. In the 1960s, Simons started trading commodities with a fellow math whiz from Harvard.

In 1978, at age 40, Simons shocked his Stony Brook colleagues by leaving the math department to start a hedge fund called Monometrics. The fund eventually became Renaissance Technologies, which established the highly successful Medallion Fund in the 1980s.

Renaissance made Simons a billionaire. He was the 55th richest person in the world, with a fortune estimated to be $31.4 billion as of March, according to Forbes magazine.

Renaissance CEO Peter Brown, in a note to employees, said on Friday that Simons “grasped that by bringing together mathematicians, physicists and engineers to formalize the science of buying low and selling high — in either order — he was likely to create something of tremendous value. Value that he would then use to fund philanthropic quests to make even more far-reaching contributions to society.”

Still, Renaissance’s success also sparked controversy for Simons, who preferred to remain out of the media spotlight.

In 2017, Newsday reported that Simons forced Robert Mercer to relinquish his post as co-CEO of Renaissance amid protests from investors about Mercer’s support for right-wing ideologues such as Steve Bannon, then-executive chairman of the website Breitbart News and chief strategist for then-President Donald Trump.

Simons was a big donor to Democrats, including Hillary Rodham Clinton who was defeated in 2016 by Trump for the presidency.

“Jim Simons loved science, understood how it could change the world for the better, and did more to make that happen than just about anybody else,” Senate Majority Leader Chuck Schumer, a Democrat, said in an X post.

In 2021, after Simons had left Renaissance, the firm agreed to pay about $7 billion to the Internal Revenue Service to settle a long-running battle over tax avoidance measures taken by some executives.

At Stony Brook University on Friday, Simons was lauded for his contributions. 

“Jim forever impacted Stony Brook,” said university president Maurie McInnis. “His passing leaves an enormous hole in the hearts of all who were fortunate to know him.”

Besides his wife, Simons is survived by three children, five grandchildren and a great grandchild. He was predeceased by two sons.

A memorial service and other events are being planned to honor Simons. More information will be posted on the foundation's website: simonsfoundation.org.

By James T. Madore

james.madore@newsday.comJamesTMadore

James T. Madore writes about Long Island business news including the economy, development, and the relationship between government and business. He previously served as Albany bureau chief.