Some words about market efficienc An inefficiency ought to be an exploitable opportunity. If there is nothing investors can properly exploit in a systematic way, then it is very hard to say that information is not being properly incorporated into stock prices; Richard roll Financial markets are efficient because they dont allow investors to earn above-average returns without taking above-average risk---Burton malkiel The efficient markets theory holds that the trading by investors in a free and competitive market drives security prices to the true fundamental values. the market can better assess what a stock or a bond is worth than any individual investor ---Andrei shleiferSome words about market efficiency • An inefficiency ought to be an exploitable opportunity. If there is nothing investors can properly exploit in a systematic way, then it is very hard to say that information is not being properly incorporated into stock prices;--- Richard Roll • Financial markets are efficient because they don’t allow investors to earn above-average returns without taking above-average risk---Burton Malkiel • The efficient markets theory holds that the trading by investors in a free and competitive market drives security prices to the true “fundamental” values. The market can better assess what a stock or a bond is worth than any individual investor.---Andrei Shleifer