Asset allocation is based on the proven theory that the type or class of security you own is much more important than the particular security itself. Asset allocation is a way to control risk in your portfolio. The risk is controlled because the six or seven asset classes in the well-balanced portfolio will react differently to changes in market conditions such as inflation, rising or falling interest rates, market sectors coming into or falling out of favor, a recession, etc.
Asset allocation should not be confused with simple diversification. Suppose you diversify by owning 100 or even 1,000 different stocks. You really haven’t done anything to control risk in your portfolio if those 1,000 stocks all come from only one or two different asset classes-say, blue chip stocks (which usually fall into the category known as large-capitalization, or large-cap, stocks) and mid-cap stocks. Those classes will often react to market conditions in a similar way-they will generally all either go up or down after a given market event. This is known as “correlation.”
Similarly, many investors make the mistake of building a portfolio of various top-performing growth funds, perhaps thinking that even if one goes down, one or two others will continue to perform well. The problem here is that growth funds are highly correlated-they tend to move in the same direction in response to a given market force. Thus, whether you own two or 20 growth funds, they will tend to react in the same way.
Not only does it lower risk, but asset allocation maximizes returns over a period of time. This is because the proper blend of six or seven asset classes will allow you to benefit from the returns in all of those classes.