"Markets are not rational. Markets are not irrational. Markets are adaptive — they coordinate the evolutionary responses of participants to changing environments. The efficient market hypothesis is a special case of a much larger coordination dynamic. Evolution, not equilibrium, is the right model."
MIT finance professor who replaced the Efficient Market Hypothesis with the Adaptive Markets Hypothesis — the idea that financial markets exhibit evolutionary dynamics, not rational equilibrium. Markets are ecosystems where strategies, participants, and environments coordinate in ways that produce periods of efficiency and periods of chaos.