“If the random-walk view is correct, today’s stock prices embody all relevant information. The only thing that would make them change is the availability of new information. Since we have no way of knowing what that new information might be, there is no mean for stock prices to regress to. In other words, there is no such thing as a temporary stock price-that is, a price that sits in limbo before moving to some other point. That is also why changes are unpredictable.”
