From Albert Bridge Capital: In Thinking Fast and Slow, Daniel Kahneman wrote of his trips with Richard Thaler to visit and evaluate investment firms.
The industry baffled him initially. But after some time, he said, "my questions about the stock market have hardened into a larger puzzle: a major industry appears to be built largely on an illusion of skill. Billions of shares are traded every day, with many people buying each stock and others selling it to them. Most of the buyers and sellers know that they have the same information, and they exchange stock primarily because they have different opinions. What makes them believe they know more about what the price should be than the market does? For most of them, that belief is an illusion."