Jim Simons and the Medallion Fund: Deciphering the Ghost in the Machine byJerome D. •February 16, 2026 Gleuschk, CC BY-SA 3.0 , via Wikimedia Commons Jim Simons was not a trader. He was a world-class mathematician and a codebreaker for the IDA. When he turned his attention to the markets in 1978, he didn't hire MBAs or Wall Street veterans; he hi…
