Jim Simons was many things to many people. He was a witty and devoted friend, a distinguished mathematician, a dedicated teacher, a revolutionary in finance, and a determined and farsighted philanthropist. Above all else, he was a brilliant mind whose constant curiosity, passion for learning, and love of beauty struck everybody who knew him. Some of the people whose lives he changed share their memories of Jim.

Jim Simons died on May 10, 2024, leaving behind a monumental legacy. Below are just a few of the stories, messages and memories of Jim that were shared with the Simons Foundation community.
I enjoyed [Jim’s] childlike wonder at the smallest things. At our last lunch together, he made a point to take me to an exit stairwell [at the Simons Foundation’s Flatiron Institute] and told me to look downward. “Yeah – So what?” I asked. “Isn’t it beautiful?” he responded. And then I realized it was beautiful. Spiral-like symmetry, with a touch of vertigo. That stairwell has it all .. but you had to be able to see it.
– Chris Palmedo
Jim’s broad curiosity, his deep and attentive listening, his sincere interest in everyone and his greatness of spirit created an environment where everyone at the Simons Foundation, from the most senior advisors to the most recently hired administrative staffers, felt that they were a respected professional engaged — with Jim — in great and important work.
– Andrew Millis
Jim Simons has been a visionary in many fields. His contribution to philanthropic funding of fundamental research, particularly in mathematics and theoretical physics, was a game-changer. He has enabled collaboration between scientists from very different backgrounds, all over the world. The Simons Foundation has changed my life more than any other research organization I have ever been involved with.
– Marcel Filoche
Jim had heard that I cloned the Rett syndrome gene and was curious to learn more about how a sporadic disorder like Rett was genetic. We had a wonderful discussion – with Jim often closing his eyes to listen, and then asking the most thoughtful question. After an hour or so of discussion, Jim asked how I might use Rett syndrome to better understand autism. I suggested that perhaps if we deleted the Rett gene in various neurons we might learn which neurons drive the autism phenotype. He perked up and funded the project on the spot. Those studies helped us reveal the importance of excitatory/inhibitory balance in autism and truly shaped my thinking about how to approach autism. From the day of our first meeting and through dozens of subsequent interactions, I found Jim to be the most insightful, straightforward and genuine person.
– Huda Zoghbi
We were talking a few days ago and reminiscing about the extraordinary impact that Jim had on the careers of so many postdocs and students in PriME <link>. what we recall most fondly is our first meeting at the foundation — we recall being blown away by how much time Jim decided to spend with us that day, by his curiosity for our field and the great questions he asked, and by how decisively he moved in kicking off our collaboration. Seven years and 100+ papers later, we still trace back the origin of the community that we’ve been able to create to that first instant in time.Jim and Marilyn’s philanthropy has helped to create a PriME network and family that will accompany many of us throughout our careers.For this, and much more, Jim will forever have our most sincere gratitude. And it is in that spirit that we will continue to produce our very best work.
– Roman Stocker and Otto Cordero
Emmanuel Candès
The Simons Chair in Mathematics and Statistics
Professor of Mathematics, of Statistics, and of Electrical Engineering (by courtesy)
Director of Stanford Data Science
Stanford University
I’d like to relate a conversation Jim and I had during our first meeting:
Jim: so, what are you doing?
Emmanuel: I work on statistical theory and methodology.
Jim: oh, that’s strange. In my view, statistics is an empirical science, so why do theory?
Emmanuel (with heart beating fast and searching for an answer): well, Jim, while what you say is true, there are theoretical aspects that are fascinating. For instance, do you know about Stein’s paradox?”
Jim: No. What is it?
(I proceeded to give him a provocative example which may have been something like this:1 say you have a baseball player, soccer player, and football player, and you wish to estimate the true mean number of home runs, goals, and touchdowns each scores per year. If you have their last ten seasons worth of data for each, then the obvious thing to do, for each player, is to estimate the true yearly mean score for each player by their average yearly scores from the last ten years. (E.g., the baseball player hits an average of 20 home runs each year, so let’s estimate their true mean yearly home runs by 20). Stein’s Paradox says that you can actually do a lot better than this. Even crazier, you should use data about the football player and soccer player to make predictions about the baseball player and vice-versa. This is deeply unintuitive since the players aren’t related to each other at all. The phenomenon only holds with at least three players; it doesn’t work for two.)
Jim: This does sound crazy. Should I believe you?
Emmanuel: This is a mathematical fact.
Jim: Do you have a proof?
Emmanuel: I think so.
Jim: I would like to see it.
At this point, we were having lunch at the Simons Foundation, and he stood up and said: “show me!” We walked to a white board, he gave me a color marker and asked me to explain. We had fun at the board that day.
This is the person I got to know: curious, lively, sharp as a razor, and fun.
…Some people make an impact in any field they turn their mind to: Jim was one of these exceptional individuals. The repercussions of his academic achievements continue to reverberate through the discoveries of those who have since tread the paths he laid. His philanthropic support has changed how we see the world in every sense, from the wide expanse of the universe to the small cells that make-up our day-to-day experience.
Jim leaves behind him many legacies; testament to a life fully and well-lived…
– Michael
Dr Michael Spence
President & Provost
Office of the President and Provost, UCL
I met Jim on November 12, 2016, when he spoke in front of a rapt audience in the Stony Brook University Center for Geometry and Physics that bears his name. There, he spoke about his life in mathematics. During the Q&A, someone asked: You’ve been so successful by using mathematics to guide decision-making–you famously said “we never override the computer” at Renaissance. So, professor, how has mathematics guided decisions in your life?
Jim pondered this question solemnly for almost an entire minute.
Not at all, he said.
Shaun Datta
Stanford University | ICME | Ph.D. Candidate
In 2019, George Wein asked me to take over his position as Director of the Newport Folk and Jazz Festivals. I was the only other person to hold the position since the founding of the festivals in 1954. As you can imagine, a few of George’s closest supporters were hesitant to embrace me as the new leader, skeptical that I – the “kid” – would be able to fill his shoes. Not Jim. Jim was supportive from day one. I still remember the first thing he said to me when we met: “so you’re the crazy son of a gun who’s taking over for George”. We then proceeded to have one of the most memorable conversations of my career about the importance of music and the arts.
Knowing that I had Jim’s support was crucial to my confidence as a leader. I am not sure I would still be in this position five years later, if it hadn’t been for his continued support and guidance. I can imagine Jim had that effect on a lot of people.
With love,
Jay
In August 2001 I moved to NY, after teaching math for five years on the island of Dominica. The twin towers fell that September and I questioned whether I should just move back home and not bother with the pursuit of higher education.
I stayed, and in 2004 graduated with a BS in Mathematics from Brooklyn College. One of my professors told me about Math for America, a new program starting off to support and grow Math teachers in NYC. He spoke about pursuing a Masters Degree at NYU…
I applied, not even hoping to get accepted; I was ready to return to my island and continue teaching and sharing my love for mathematics.
Fast forward to now and I am currently the Math Coach and an Assistant Principal at East Side Community School, where I’ve been for the last 19 years.
All this is because of Dr. Simons. I’ve met him many times because of Math for America but he won’t ever know how much he has changed the entire trajectory of my life. But I can repay him by paying it forward. By engaging students in rigorous mathematics. By coaching and guiding math teachers. By sharing my love for mathematics.
He changed teachers’ lives in ways he could not have ever anticipated when he started and funded MfA.
– Giselle George
Many good things have been said about Jim Simons, but none yet have mentioned Jim’s enormous contributions to fusion energy, which may be one of his most lasting legacies.
Jim was a visionary, and his contribution to advancing fusion has left an indelible mark – a legacy that will continue to shape the future of energy production. He understood deeply the lasting promise of fusion energy as a solution to humanity’s energy needs. He also recognized the tremendous value that his quantitative methods could contribute in resolving the fundamental challenges of this new form of energy production.
Over the years, I frequently ran into him when visiting the Simons Foundation. He always greeted me, not by calling out my name, but by saying: “Ah, Stellarators! How are they doing?”
The Simons Foundation created a collaboration that brought together esteemed computer scientists, mathematicians, and physicists to advance stellarator physics. It has become the world’s largest stellarator collaboration in theory and computing.
This collaboration produced the Simons Optimization code (SIMSOPT), which enabled some of the most advanced and precise designs of stellarator magnetic fields. These designs have inspired companies to undertake stellarator fusion as their principal objective, something Jim very much enjoyed seeing.
In one of his last meetings with me on the 11th floor of the Flatiron Institute, he told me that he expected to be around for the first stellarator fusion reactor. He did change the world, but he left us too soon.
– Amitava Bhattacharjee
Professor of Astrophysical Sciences
Princeton University
I met Jim for the first time in 1979 in Berkeley, at the celebration for S.-S. Chern’s retirement. Jim spoke about the great experience he had working with Chern. By that time, of course, he had already embarked on his conquest of the financial world and had, apparently, ‘left mathematics’. I remember Jim at that time relating the story that at the time, when so many mathematicians were lamenting his loss, he had heard it reported that Chern had, in his characteristic style, smiled softly and remarked, “It’s not a disaster; after all, Jim Simons is not David Hilbert”. Jim told the audience that he had always admired Chern’s tact in making that remark, because, “after all, Chern didn’t have to reach quite so high”.
– Robert L. Bryant
I first met Jim during the Spring of 2011 in the elevator of the Math Tower on the Stony Brook University campus. At that time, I had just accepted a Simons Postdoctoral Fellowship and so, overcoming a bit of shyness, I decided to thank him for the institution of these generous fellowships… I commented on the competitive pay, the reduced teaching load, and the travel money that came with the fellowship. A bit surprised, he congratulated me, he then asked who my adviser was. And then a quirky expression lit up on his face and he added: “Save some money, your next position may not pay as well!”. After that he laughed together with a colleague and walked away after we reached the fifth floor. Of course, he was right! Fortunately, those words stuck in my head and indeed I managed to save some money and get started in life!
– Luca & Kate Di Cerbo
In the decade or so before I first arrived in Stony Brook, Jim Simons had single-handedly converted our once-obscure mathematics department into a research powerhouse. But by the time I first set foot on campus, Jim had already resigned his academic position, and gone into finance.
Jim eventually decided that he missed mathematical research, and accepted a new position, as Research Professor, in our department. He stipulated, however, that the salary for this position must be $0 per annum. When he was elected to the National Academy of Sciences in 2014, I proposed that we double his salary, and Jim seemed to enjoy the joke.
Discussing mathematics with Jim was always a special pleasure. Some of our best conversations were carried out over the phone, and these would often begin with the formality of his secretary calling to ask if I could speak to Jim immediately.
He was always interested in learning something new, even when I had to explain why something he’d hoped to try couldn’t possibly work. That’s is exactly the attitude one needs to do mathematics. And Jim was indisputably a great mathematician.
I always enjoyed Jim’s wry sense of humor. On one occasion, my wife Dolores, who’s a historian, gave him a copy of her very first book, which studied the rise and fall of leading business families in pre-World-War-I Germany. Jim’s response was to ask, “Do you know my definition of a good family?” Dolores shook her head. “It’s a family that used to be a lot better!” This we found not only funny, but also interestingly wise.
But Jim was also a source of wisdom in more serious situations.
At Stony Brook, a new Dean of Libraries announced that our Mathematics/Physics library would be closed, and that our journals and books would be “shipped offsite”. I got up in the middle of the night and sent the fellow a rather intemperate e-mail. Jim took me aside at lunch the next day, and told me that the wise Abraham Lincoln filed every outgoing letter t for several days; he would then tone down or destroy many of these letters before they were sent. I took this to heart, and have tried to implement a similar policy ever since. But in the meantime, the Dean of Libraries was replaced, and our library was saved. I am certain that this was Jim’s doing, but, as usual, he never took credit for solving the problem.
– Claude LeBrun
Jim allowed me to visit Renaissance out in Stony Brook. The scales fell from my eyes – I saw for the first time something truly new in investing. the people I met were not Wall Street folks. Indeed, as best I can remember I think only one person on staff had any background on the Street. I met twins from Princeton’s faculty, I met someone who left MIT because he could not get funding (for his astronomy? work) who told me he just wanted to make a lot of money so he could go back and self-fund his research. I met employees who regaled me with tales of a blackout on the Island but Renaissance had powerful generators so they could work through the night – but they took a 1AM break to play whiffle ball. In sum, everyone seemed to have the purity of research first and foremost in their DNA…the astounding results were simply a by-product of this thirst. What a remarkable man and organization.
– Steve Galbraith
It was in the time before COVID-19, back in 2019, when I was a postdoctoral researcher under the guidance of Prof. Dmitri Basov at Columbia University. During that period, a workshop was being held at the Flatiron Institute, yet a few of us found ourselves barred from entry, likely due to an oversight.
Spotting our group, Jim inquired about the situation. Eager to attend the conference, I promptly explained that we were from Columbia University and wished to participate.
Without hesitation, Jim instructed the doorman to allow us entry.
That morning’s quick interaction with Jim, and the brief moments to walk together have stayed with me ever since. I believe it is because I was deeply impacted by Jim’s remarkable personal field and aura.
Although Jim left us, this short but never-forgettable interaction with Jim permanently printed in my mind. Jim’s fans — including me — are still working hard towards the big vision inspired by him.
– Guangxin Ni
My name is Brady Ryan, I’m a high school senior who is planning on attending Marist College in a few months. I am writing to share with you the profound impact that Jim Simons had on my life and academic journey. Inspired by his groundbreaking contributions to mathematics and finance, I have chosen to pursue a path of study in these fields. Currently, I am preparing for my AP Calculus exam while eagerly anticipating my future studies in finance and mathematics at Marist College.
Jim Simons’ dedication to advancing mathematics and his philanthropic efforts, particularly his contributions to Stony Brook University and New York State, deeply resonate with me as a New York State resident. While I never had the privilege of meeting Jim personally, his work has been a constant source of inspiration and motivation for me. I’ll always remember watching YouTube videos late at night about complex topics like quantitative analysis and topography, but the stories about Jim’s life were what really stuck out to me. His legacy will continue to influence and shape the lives of aspiring mathematicians and financiers like myself for generations to come.
– Brady Ryan
Over the years, Jim and I talked about audacious aspirations, seeking out people who were smarter than ourselves, finding leaders who were both brilliant and selfless, constructing institutional structures and culture that encouraged deep collaboration, and creating fertile ground for people to go after the biggest problems. Both of us spoke our minds, for better or for worse. And both of us had an unshakable belief in the power of human ingenuity to solve the world’s most urgent problems.
I will miss Jim’s sage advice, warm support, wry sense of humor, and boundless optimism.
– Jennifer Tour Chayes
As I read the news of Jim’s passing it brought me so much sadness… I had the great honor and privilege of working for Jim and Marilyn on their boat.
What a great experience it was in my life. My most touching memory of Jim (there are many) is when we were in Jamaica and Jim and the family were onboard, as per usual Jim was up early and having his coffee and I noticed he was attentively writing on a paper and as I was about to pour some more coffee for him I saw that he was doing some mathematical formula. I have to point out that I have never been a big fan of math, and I asked him why he wasn’t outside enjoying the beautiful views and weather and his response to me was: doing mathematics is very relaxing for me. I was shocked since I have a strong aversion to math. I was never able to have good grades in school, and I told him that I hated math and he was then himself shocked and told me: “I tell you what, I will make you love math.”
Low and behold, the following summer when M/Y Lord Jim was based in NY I had a private tutor in math for the whole summer graciously provided by Jim. Did I understand math better right after the tutoring no, but sometimes your brain works in mysterious ways. Three years ago (at 44 years old) I decided to go back to University (McGill in Montreal) in Project Management and during one semester the lecturer said next class we will do some statistics… My heart started pounding and I became nauseous, to tell you how I was not looking forward to that class at all is a major understatement. That day came and as the class started somehow all that tutoring came rushing back and I was able to not only succeed in my class on statistics (with A’s) but also appreciate statistics on a new level, it all made sense somehow.
Sometimes, we only realize later in life the impact a person has had.
– Yannick De Garie