Jim Simons passed away at his home in Manhattan on May 10, 2024, at the age of 86.

Throughout his life, Jim Simons made significant contributions to both mathematics and quantitative investment, utilizing his intelligence, perseverance, and innovative spirit. His pioneering achievements in the field of differential geometry have earned him a place among the elite geometers. After turning to the investment sector at 40, he became a pioneer and leading figure in modern quantitative investment, boasting decades of investment performance that could rival any investor, including the Buffett Partnership. Simons summarized his life in three sentences: “I did a lot of mathematics, I made a lot of money, and I gave most of it away.”

An Elite Geometer

James Harris Simons was born on April 25, 1938, in Brookline, Massachusetts, the only child of shoe factory owner Matthew Simons and homemaker Marcia (Kantor) Simons. He exhibited a talent for mathematics from an early age, demonstrating a strong intuition for numbers and shapes. By the age of 3, he could calculate 2 to the 10th power as 1024. After graduating high school, he pursued a mathematics degree at MIT, where he realized he might not become a top-tier mathematician but could still achieve significant mathematical work. It was also at MIT where he saw distinguished mathematicians like Warren Ambrose and Isadore Singer enthusiastically discussing mathematical problems at a midnight corner café, making him realize that cigars, coffee, and mathematics were the life he wanted.

Simons completed his undergraduate degree in three years and planned to pursue a Ph.D. at MIT, but his advisor recommended he study differential geometry with Professor Shiing-Shen Chern at the University of California, Berkeley. Awarded a scholarship by Berkeley’s mathematics department, Simons arrived in Berkeley in the summer of 1959. However, Professor Chern was on sabbatical that year. Simons then joined Professor Bertram Kostant’s group and began his Ph.D. thesis. Except for the introductory part, his Ph.D. research went smoothly. Within two years, he completed his thesis, offering a new proof of Berger’s classification of complete groups on Riemannian manifolds. The thesis was soon published in a prestigious academic journal, earning him an opportunity to teach at MIT.

From 1962, Simons taught at MIT and Harvard University, where he was assigned to teach a course on “Partial Differential Equations” to senior graduate students. Despite not having systematically studied this subject before and being unfamiliar with the course content, his engaging teaching style was popular among students. They were astonished to learn that Simons had only started learning the course material a week before them.

In 1964, Simons took a new position at Princeton, joining a joint endeavor between the Institute for Defense Analyses (IDA’s CRD) and the U.S. Department of Defense, where he worked in the Communications Research Division, assisting in decrypting Soviet codes. For over a decade, there had been little progress in breaking Soviet codes. Simons began applying theories from mathematical statistics and probability to develop algorithms, making significant advances and receiving commendation from the Department of Defense. The new job paid twice as much as teaching at Harvard, allowing him to continue researching topics of interest. In 1968, he published a seminal paper on geometry, “Minimal Varieties in Riemannian Manifolds,” in the Annals of Mathematics, establishing his significant position in the field of geometry. That year, Simons was dismissed from the research institute for publicly expressing strong anti-Vietnam War views.

As Simons’ reputation in the mathematical community was rising, he was invited by John Toll, the president of Stony Brook University, to become the head of the mathematics department. With substantial funding from the New York State government, President Toll aimed to transform Stony Brook into the Berkeley of the East Coast, having already recruited Chen Ning Yang to head the physics department. After a five-year search for a suitable department head, 30-year-old Simons took on the role at Stony Brook. From 1968 to 1978, he served as the head of the mathematics department, focusing on recruiting top mathematicians. Through his efforts, the department’s status steadily rose, becoming one of the world’s leading centers for geometric research.

Simons’ mathematical research, starting with his Ph.D. thesis, primarily focused on the geometry and topology of manifolds. Although Shiing-Shen Chern was not his direct thesis advisor, he was a member of Simons’ thesis defense committee. Simons later collaborated with Chern on geometric research, leading to the publication of joint papers in 1971. In 1974, Simons discovered an invariant characteristic class on 3-dimensional manifolds and shared his findings with Chern, who realized its applicability to higher-dimensional manifolds. This collaboration resulted in the classic achievement in differential geometry—the Chern-Simons secondary characteristic classes on Riemannian manifolds. Mathematicians and physicists such as Edward Witten, Albert Schwarz, and David Thouless later found these characteristic classes to have numerous applications in fields like topological quantum field theory, string theory, condensed matter physics, and supergravity. They are also related to the Yang-Mills functional on 4-dimensional manifolds, leading to profound discussions and exchanges between Yang and Simons. Three scientists from the UK and the US used the Chern-Simons theory to describe the fractional quantum Hall effect, earning them the 2016 Nobel Prize in Physics, highlighting its significant impact on modern physics. These contributions, among others to geometry and topology, earned Simons the 1976 Oswald Veblen Prize in Geometry from the American Mathematical Society (AMS). This award, presented every five years, is the highest honor in the field of geometry.

Even after transitioning to the investment industry, Simons never completely left mathematical research. He later published groundbreaking studies on pattern recognition, string theory, and the integration of geometry, topology, and quantum field theory, leading to his election as a fellow of the National Academy of Sciences in 2014.

Long-Term Investment Performance that Commands Respect

Simons recognized the importance of money early on. During his Ph.D. studies at Berkeley, he began investing in commodities using wedding gift money from relatives and friends, achieving notable success. While working at the Institute for Defense Analyses, he co-authored a paper attempting to predict commodity and security prices using differential equations. In 1976, Simons entrusted a former student he had taught at Harvard to manage a sum of money for him. This student used mathematical and statistical models to predict the price of sugar, achieving remarkable results and multiplying the assets tenfold within a year. Simons reaped substantial rewards, reigniting his strong desire for wealth. He decided to apply his talents to a more mundane discipline—earning as much money as possible in the shortest amount of time. In 1978, he left academia and rented an office in a small shopping center in Setauket, Long Island, to found Monemetrics. He believed that he and his small team of mathematicians, physicists, and statisticians (mainly former university colleagues) could analyze financial data, identify market trends, and make profitable trades. He aimed to prove that the prices of commodities, currencies, stocks, and bonds could be predicted using calculus and partial differential equations, much like deciphering Soviet codes using algorithms from mathematical statistics and probability theory. Eschewing financial analysts and business school graduates, Simons hired like-minded mathematicians and scientists, equipping them with advanced computers to process vast amounts of data filtered through mathematical models.

Initially, using mathematical models to predict currency fluctuations was quite successful, and Monemetrics earned decent profits. However, when expanding into the bond market, losses began to mount, persisting for over half a year. At one point, Monemetrics’ computer program identified an opportunity in potato prices, purchasing a large amount of Maine potato futures and nearly controlling the market. This attracted opposition from the Commodity Futures Trading Commission, responsible for overseeing futures trading. As a result, Simons had to sell his investment, missing out on significant potential profits.

After four years of ups and downs, Monemetrics was renamed Renaissance Technologies. Initially focusing on currencies and commodities, Simons and his team of scholars faced numerous challenges in applying mathematical models to make trading decisions. From currency exchange rates to commodities, bonds, stocks, and futures, each expansion and diversification of investment targets was accompanied by considerable losses. Key early partners in Simons’ team included Lenny Baum, who co-authored a price fluctuation prediction model with Simons at the Institute for Defense Analyses; James Ax, a top number theorist whom Simons had recruited from Cornell during his tenure as department head at Stony Brook; information coding theory expert Elwyn Berlekamp; computer and big data specialist Sandor Straus; complex analysis expert Henry Laufer; and stochastic differential equations expert René Carmona. Each made significant contributions to the evolution of Renaissance’s trading system and price database at different times. From 1978 to 1990, Renaissance’s trading algorithm system and price database underwent continuous evolution and iteration, gradually taking shape. Meanwhile, the U.S. capital market welcomed a bull market following the Cold War victory.

Renaissance’s true wealth emerged when it entered the stock market, a much larger market than currencies and commodities. Stocks and bonds had long been considered the domain of Wall Street brokerages, investment banks, and mutual fund companies, where young, tireless MBAs analyzed public companies and passed their findings to senior wealth managers, who relied on experience and intuition to select market winners.

Renaissance Technologies’ hedge funds, led by Simons, traded in markets worldwide, using mathematical models to analyze and execute trades. Renaissance employed computer-based models to predict financial instrument price changes based on analyzing as much collected data as possible, looking for non-random movements to make predictions. Many of Renaissance’s trading decisions were data-driven, focusing solely on data patterns and correlations without making causal judgments, and were fully automated. The system aimed to capture short-term price differences in the market, quickly entering and exiting trades, often holding a security for no more than two days, sometimes even shorter.

Wall Street firms initially ridiculed Renaissance’s “math nerds” and their quantitative methods. However, by 2020, the quantitative investment approach led by Renaissance accounted for nearly one-third of Wall Street’s trading business. Even traditional investment companies that relied on corporate research, intuition, and personal contacts felt compelled to adopt some of Renaissance’s computer-driven methods. For most of its existence, Renaissance’s fund was Wall Street’s largest quantitative fund, significantly changing the way hedge funds traded and how they made money for their wealthy investors and pension funds.

Renaissance Technologies’ four investment funds became virtual money-printing machines. Medallion, the largest of these funds, generated over $100 billion in trading profits over 30 years since its inception in 1988. During this period, it achieved an unheard-of average annual return of 66%. Even after deducting fees and profit sharing, fund clients enjoyed an average annual net return of 39.1%. This investment performance is unmatched by any investor, including the Buffett Partnership.

In 2006, Simons was named Financial Engineer of the Year by the International Association of Financial Engineers. In 2020, his personal income was estimated at $2.6 billion, with $2.8 billion in 2007, $1.7 billion in 2006, $1.5 billion in 2005 (the highest-paid hedge fund manager that year), and $670 million in 2004. When Simons retired as CEO of the company in 2010, his net worth had reached $11 billion. At the time of his death, Simons’ estimated net worth was $31.4 billion, making him the 51st richest person in the world.

If two monuments were erected in the contemporary investment hall of fame, one would be for the Buffett Partnership, showcasing an average annual return of nearly 20% over more than 50 years; the other would be for Simons’ Renaissance team, showcasing an average annual return of over 60% for more than 30 years. Others, even if famous or having made a fortune temporarily, would merely be passing visitors. Their long-term performance might not withstand significant statistical hypothesis testing, and whether their success was due to luck or genuine skill remains debatable.

Philanthropic Endeavors

While continuing to manage his funds as chairman of Renaissance, Simons increasingly devoted his time and wealth to philanthropy.

Simons and his wife Marilyn Hawrys Simons co-founded the Simons Foundation in 1994, a charitable organization supporting scientific research, education, and health-related projects. The Simons Foundation established the Simons Foundation Autism Research Initiative (SFARI) in 2003 as one of its scientific programs. SFARI’s mission is to improve understanding, diagnosis, and treatment of autism spectrum disorders.

In 2004, Simons founded Math for America with the mission to improve math education in U.S. public schools by recruiting more high-quality teachers. The Simons Foundation initially committed $25 million, which Simons doubled in 2006. The foundation continues to fund its operations, donating nearly $22 million in 2018.

In 2006, Simons and his wife donated $25 million to Stony Brook University through the Simons Foundation, the largest donation to a State University of New York school at the time. On February 27, 2008, the Simons Foundation donated $60 million to establish the Simons Center for Geometry and Physics at Stony Brook, the largest donation to a public university in New York State history. In 2011, the couple broke this record again by donating $150 million to Stony Brook for medical science research, constructing a life sciences building, establishing a neuroscience research institute and a bioimaging center, researching cancer and infectious diseases, funding 35 new professorships, and providing 40 graduate scholarships. In 2023, the university announced a $500 million donation from the Simons Foundation, the second-largest donation to a public university in history.

Simons is one of the largest contributors to his undergraduate alma mater, MIT. The couple and their foundation funded the renovation of the math department building, named in their honor in 2016, and supported the Simons Center for the Social Brain. Simons is a lifetime honorary member and board member of the MIT Corporation.

Simons is a major donor to his graduate alma mater, UC Berkeley. On July 1, 2012, the Simons Foundation pledged $60 million to establish the Simons Institute for the Theory of Computing at Berkeley, a leading collaborative research institution in theoretical computer science. In 2020, the foundation made individual grants totaling over $46 million to Berkeley to increase the institute’s endowment and support its operations. In October 2023, the university announced an additional $25 million matching commitment from the Simons Foundation to the institute. Simons and his wife have also provided significant funding to Berkeley-affiliated institutions, especially the Simons-Laufer Mathematical Sciences Institute and the Berkeley Lab.

The Simons Foundation has become one of the largest private funders of basic scientific research. In 2016, the foundation established the Flatiron Institute, housing 5 groups of computational scientists (each with 60 or more PhD-level researchers). The institute comprises four cores or divisions: CCB (Center for Computational Biology), CCA (Center for Computational Astrophysics), CCQ (Center for Computational Quantum Mechanics), CCM (Center for Computational Mathematics), and CCN (Center for Computational Neuroscience). Located in Manhattan, the institute represents a significant investment in foundational computational sciences.

Additionally, the Simons Foundation donated the Chen-Simons Building to Tsinghua University and is a major donor to healthcare in Nepal.