引言

Modern portfolio theory is based on the concept of "efficient markets." In an efficient market, information about securities is so wide spread and so well analyzed that it is extremely difficult to "beat the market" by knowing just when to buy or sell individual securities based on information or analysis that no one else has.

The focus of modern portfolio managers has shifted from individual securities to the portfolio as a whole. The goal is not to get a hot tip on a blockbuster stock, but to construct a well-balanced portfolio that will allow the holder to achieve a desired return while reducing risk as much as possible.

To do this, portfolio managers use the principles of Asset Allocation which will be discussed in further detail in this lesson.

Historical Risk/Return of Asset Classes