Jim Simons was a mathematician and Cold War codebreaker who ran the math department at Stony Brook before he ever traded anything. When he built Renaissance Technologies, he made the one hire most funds would consider insane: he refused to hire anyone from Wall Street. His line was that it is easier to teach smart people about markets than to teach market people how to be smart.

So Renaissance hired physicists, astronomers, statisticians, and computational linguists who typically knew nothing about finance. Some of the best came off IBM's speech-recognition team, including Robert Mercer and Peter Brown. The result is the Medallion Fund, launched in 1988 and named for math prizes Simons and James Ax had won. Its record is the one number every quant knows: roughly 66% gross and around 39% net annualized over three decades, through a 5% management and 44% performance fee that would be laughed out of any other fundraise.

The discipline is in what Simons refused to do with it. In 1993 he closed Medallion to outside money. It is now owned by employees and alumni only. And rather than scale it, he capped it at around $10 billion, because the strategies are short-term and more capital would erode the edge. When you find a money-printing machine, you do not grow it. You keep it small, keep it secret, and optimize return per dollar. Most firms die trying to get bigger. Renaissance won by refusing to.

The shop is tiny by hedge-fund standards: around 300 people, a third of them PhDs, heavy on Stony Brook, run like a university with weekly scientific seminars. The Medallion code is one monolithic system every researcher can read and edit, so a string theorist with an idea about commodities can go change the commodities model. No compartmentalization, total collaboration, lifetime non-disclosure on the way out. Simons died in 2024 at 86. The firm still does not hire from Wall Street.

The recruiter's read: this is the purest statement of the thesis the whole industry quietly runs on. Domain experience is overrated and often a liability, because it ships with the conventional wisdom you are trying to beat. Raw scientific ability is rare and teachable toward any problem. Simons did not find people who understood markets. He found people who could understand anything, and pointed them at one.