Saturday, May 9, 2009

Efficient Markets Theory by ROBERT BELL

The efficient markets theory is the idea that speculative asset prices always incorporate the best information about fundamental values and that prices change only because new information enters the market and investors act in an appropriate, rational manner with regards to this information. This idea dominated academic fields in the early 1970s. Efficient markets theory is an elegant attempt to tether asset prices to fundamentals through the common-sense notion that people would not behave in irrational ways with their money in financial markets. This theory is encapsulated by the "Value Investment" paradigm prevalent in much of the investment community.

In an efficient market, prices are tethered to perceived fundamental valuations. If prices fall below the market's perception of fundamental value, then buyers will enter the market and purchase the asset until prices reach their perceived value. If prices rise above the market's perception of fundamental value, then sellers will enter the market to sell the asset at inflated prices.

Efficient markets theory explains the majority of market behavior, but it has one major flaw which renders it inoperable as a forecasting tool: it does not explain those instances when prices become very volatile and detach from their fundamental valuations. This becomes painfully obvious when adherents to the theory postulate new metrics to justify fundamental valuations that later prove to be completely erroneous. The failed attempts to explain anomalies with the efficient markets theory lead to a new paradigm: behavioral finance theory.Lawrence Roberts is the author of The Great Housing Bubble: Why Did House Prices Fall? Learn more and get FREE eBooks at: http://www.thegreathousingbubble.com/ Read the author's daily dispatches at The Irvine Housing Blog: http://www.irvinehousingblog.com/ Visit Efficient Markets Theory.

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