Summary and review ofThe Man Who Solved the Market

Reviewed by Diario de un Inversor · UpdatedJuly 17, 2026

Our review

Jim Simons is probably the most profitable investor in history and, until this book, also the least known. Gregory Zuckerman, a veteran Wall Street Journal reporter, spent years breaking through Renaissance Technologies' secrecy to reconstruct how a brilliant mathematician — Veblen Prize geometer, codebreaker for US intelligence — decided at forty that markets could be modelled like any other system with hidden signals. The result was the Medallion fund, with average annual returns above 60% before fees for three decades: numbers no traditional investor has ever approached. The book shines on two fronts: the human story — ego battles among mathematicians, Simons's family tragedies, Robert Mercer's political role — and an accessible explanation of how quantitative investing works without revealing (nobody knows them) the specific signals. The uncomfortable lesson is explicit: if history's best returns were achieved by a team that ignores fundamentals and distrusts human judgment, what does that say about traditional analysis? Zuckerman leaves the question honestly open.

Key takeaways

• Medallion proved exploitable systematic inefficiencies exist — but exploiting them took the best mathematicians in the world, data nobody else had, and a culture of secrecy.
• Simons rarely had opinions on stocks: his bet was methodological — the model decides, and humans do not intervene even when the model is losing.
• Renaissance's edge is not a formula but a process: gather more data, hire better scientific talent, and compound small statistical advantages millions of times.
• Quant success does not transfer to individual investors; the applicable lesson is process discipline and distrust of one's own intuitions.

Fact

Renaissance's Medallion fund returned an average of 66% annually before fees between 1988 and 2018, according to Zuckerman's data; the Spanish edition was published by Valor Editions in 2020.