Jim Simons

Biography

Born 25 April 1938 in Massachusetts; died 10 May 2024 in New York City, aged 86. Mathematician who taught at MIT and Harvard and worked as an NSA codebreaker through the Institute for Defense Analyses. Chaired the Stony Brook mathematics department from 1968 to 1978 and co-created Chern–Simons theory (1974). Started the firm that became Renaissance Technologies in 1978, stepped down as CEO in 2010 and as chairman in 2021. Medallion returned outside investors' money and is open only to employees; Simons judged it could not run much more than about $10 billion.

In their own words