Business
The author argues that, all else equal, turning decisions over to rule-based systems works better than relying on narratives. Investors overrate their ability to judge executives and compelling stories, and get carried away by them.
In the author's account, even after enormous success the insiders don't just press a button and relax. They work with urgency and anxiety about the future and the competition for talent, like a championship team determined to win again.
The author argues that markets hold fewer easy mispricings than traditional value investors believe. To beat them you need a real competitive advantage, and an edge built on simply knowing more is getting ever harder to find.
As a reviewer reads the book, decades of returns show that past price and trading-volume movements do carry information about where prices go next. That contradicts the textbook claim that such patterns are already priced in and can't be exploited.
The author treats the story as much a management lesson as a math one. A reviewer reads the returns as flowing more from getting brilliant, stubborn, difficult people to work together under the right incentives than from the founder's own genius.
A reviewer observes that the most skilled managers keep their returns for themselves and have no need for outside money. The flagship fund is closed to outsiders, so its gains go to insiders rather than to pension funds or ordinary savers.
A trading system can make large profits while being right only slightly more than half the time, as long as it places a huge number of small bets. In the author's account, the winners come from many faint patterns repeated constantly, not from a few bold calls.
The firm hired physicists, mathematicians and computer scientists who knew little about finance and set them hunting for hidden patterns in data. Experts scoffed, but fresh analytical skill applied to raw data outperformed traditional market knowledge.
The advantage began with painstaking work: digging large amounts of historical data out of paper records and gathering new electronic data. The models were constantly re-tuned against this data, several times an hour, to surface patterns invisible to the naked eye.
A fortune made from trading on patterns can be turned into decisive influence over politics, philanthropy and science, and that brings backlash its makers didn't foresee. Reviewers see this as the hardest part of judging whether such a firm leaves the world better off.