Efficient Market Hypothesis - EMH
Definition of 'Efficient Market Hypothesis - EMH'An investment theory that states it is impossible to "beat the market" because stock market efficiency causes existing share prices to always incorporate and reflect all relevant information. According to the EMH, stocks 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 higher returns is by purchasing riskier investments. |
|
Investopedia explains 'Efficient Market Hypothesis - EMH'Although it is a cornerstone of modern financial theory, the EMH is highly controversial and often disputed. Believers argue it is pointless to search for undervalued stocks or to try to predict trends in the market through either fundamental or technical analysis.Meanwhile, while academics point to a large body of evidence in support of EMH, an equal amount of dissension also exists. For example, investors, such as Warren Buffett have consistently beaten the market over long periods of time, which by definition is impossible according to the EMH. Detractors of the EMH also point to events, such as the 1987 stock market crash when the Dow Jones Industrial Average (DJIA) fell by over 20% in a single day, as evidence that stock prices can seriously deviate from their fair values. |
|
Related Definitions
Articles Of Interest
-
Arbitrage Squeezes Profit From Market Inefficiency
This influential strategy capitalizes on the relationship between price and liquidity. -
Efficient Market Hypothesis
An investment theory that states it is impossible to "beat the market". -
Is Stock Picking A Myth?
Find out if mutual fund managers can successfully pick stocks or if you're better off with an index fund. -
Efficient Market Hypothesis: Is The Stock Market Efficient?
Deciding whether it's possible to attain above-average returns requires an understanding of EMH. -
Making Sense Of Market Anomalies
Stocks sometimes thwart the efficient market theory by showing some very unusual patterns. -
Profiting From A Consumerless Recovery
Recovering from an economic slump isn't the easiest thing to do, but here are a few potential methods of rebuilding. -
What Is Market Efficiency?
The efficient market hypothesis (EMH) suggests that stock prices fully reflect all available information in the market. Is this possible? -
Reduce Your Risk With ICAPM
Avoid unnecesary risks involved in CAPM calculations by also incorporating ICAPM into the mix. -
Do noise traders have any long-term effect on stock prices?
There are two theories that are used to describe how securities are priced in the stock market: the efficient market hypothesis (EMH) and the inefficient market hypothesis. The EMH states that ... -
What is the "random walk theory" and what does it mean for investors?
The random walk theory is the occurrence of an event determined by a series of random movements - in other words, events that cannot be predicted. For example, one might consider a drunken person's ...
Free Annual Reports