Jim Simons refused to wear socks, chain-smoked through meetings, and answered questions about publicity by quoting Benjamin the donkey from Animal Farm. He also died in May 2024 with a fortune of more than $31 billion. This episode maps the logic of his life: a bachelor’s degree from MIT in three years, a PhD from Berkeley at 23, a motor scooter ride from Boston to Bogota, and work in geometry and topology with Shiing-Shen Chern that physicists later found they needed for string theory.

In 1964 Simons joined the Institute for Defense Analyses to break codes, then lost the job for publicly opposing the Vietnam War. A decade chairing the math department at Stony Brook taught him to manage brilliant people. His great insight came next: markets, like ciphers, only look random. At Renaissance Technologies he hired mathematicians, physicists, and astronomers instead of MBAs, hunted for tiny statistical edges, and let algorithms trade on them without fear or greed.

• The Chern-Simons form began as pure mathematics and became, decades later, a language physicists needed to describe quantum fields in three dimensions.
• IBM asked Simons to attack Lucifer, an early block cipher that preceded the Data Encryption Standard.
• The Medallion Fund, launched in 1988, averaged a 66.1 percent gross annual return and 39.1 percent after fees, earning over $100 billion in trading profits across three decades.
• In 2008 the employee-only Medallion Fund surged 80 percent while the firm’s funds for outside investors fell about 16 percent, and a 2014 Senate inquiry into basket options ended in a multibillion dollar tax settlement in 2021.
• After losing his sons Paul in 1996 and Nick seven years later, Simons and his wife Marilyn gave more than $4 billion to causes including Math for America, autism research, and the Flatiron Institute.