Note that this thought experiment does not necessarily imply that stock prices are unpredictable. For example, suppose that the piece of information in question says that a financial crisis is likely to come soon. Investors typically do not like to hold stocks during a financial crisis, and thus investors may sell stocks until the price drops enough so that the expected return compensates for this risk.
note that this thought experiment does not necessarily imply that stock prices are unpredictable for example suppose t,hat the piece of information in question says that a financial crisis is likely to come soon investors typically do not like to hold stocks during a financial crisis and thus investors may sell stocks until the price drops enough so that the expected return com,pensates for this risk