The document summarizes the book "Adaptive Markets: Financial Evolution at the Speed of Thought" by Andrew W. Lo. The book proposes the Adaptive Markets Hypothesis, which suggests that rational and irrational investor behavior coexist and financial markets evolve adaptively. It uses insights from psychology, biology, and other fields to explain how markets swing between stability and crisis. The book also explores implications including how hedge funds have become isolated financial ecosystems and lessons about the 2008 market meltdown.