Efficient Market Hypothesis Introduction Random

Transcript:Efficient Market Hypothesis Introduction Random:
Efficient Market Hypothesis Introduction Random walk hypothesis The efficient market hypothesis (EMH) is an idea partly developed in the 1960s by Eugene Fama. It is an investment theory that states it is impossible to "beat the market" because stock market efficiency causes existing shares to always incorporate and reflect all relevant information. According to the EMH, stock always trade at their fair value on stock exchanges, making it impossible for investors to either purchase undervalued stocks or sell stocks for inflated prices. As such, it should be impossible to outperform the overall market through expert stock selection or market timing, and that the only way an investor can possibly obtain the higher returns is by purchasing riskier investments. An efficient capital market is a market that is efficient in processing information. In other words, the market quickly and correctly adjusts to new information. In an information of efficient market, the prices of securities observed at any time are based on “correct” evaluation of all information available at that time. Therefore, in an efficient market, prices immediately and fully reflect available information. Definition "In an efficient market, competition among the many intelligent participants leads to a situation where, at any point in time, actual prices of individual securities already reflect the effects of information based both on events that have already occurred and on events which, as of now, the market expects to take place in the future. In other words, in an efficient market at any point in time the actual price of a security will be a good estimate of its intrinsic value." - Eugene Fama, The Efficient Markets Hypothesis The Efficient Markets Hypothesis (EMH) is made up of three progressively stronger forms: Weak Form Semi-strong Form Strong Form The EMH Graphically In this diagram, the circles represent the amount of information that each form of the EMH includes. Note that the weak form covers the least amount of information, and the strong form covers all information. Also note that each successive form includes the previous ones. All information, public and private All public information All historical prices and returns The Weak Form The weak form of the EMH says that past prices, volume, and other market statistics provide no information that can be used to predict future prices. Weak because security prices are the most easily available piece of information. Many financial analysts attempt to generate profits by