George Soros, one of the most successful macro investors in history, presents his theory of reflexivity — the idea that market participants's perceptions and the underlying fundamentals they are trying to assess are not independent variables but continuously interact with and shape each other. This creates feedback loops that cause markets to move persistently away from equilibrium rather than toward it, contrary to the assumptions of classical economics and the efficient market hypothesis. Soros developed this theory from Karl Popper's philosophy of fallibilism and applied it throughout his career at the Quantum Fund to build a methodology for identifying self-reinforcing market trends and their eventual reversals. The book includes Soros's real-time diary of his investment decisions during a period of live trading in 1985-1986, giving readers an unusually intimate view of how a master macro trader processes market information and constructs positions. Reflexivity as a concept has influenced generations of macro investors and has gained new relevance with the rise of central bank intervention and algorithmic trading, which have arguably increased the feedback loops Soros identified. Intellectually demanding but rewarding for readers willing to engage seriously with the ideas.