The US stock market has taken investors on a bumpy ride in recent years.

Market volatility has tested investor discipline and prompted some people to question their commitment to equities. While no one knows the future, looking at the past may help you gain a better view of long-term market performance and put the recent market volatility in perspective.

The above chart shows the historical distribution of US market returns since 1926. The performance years are stacked in ascending order by return range. This chart illustrates that:

• Market performance over the past two years has been severe by historical standards. In 2008, US stocks experienced their second-worst calendar return in eighty-four years. Then, in 2009, stocks rebounded strongly to deliver a return in the top quartile of the historical distribution.
• Over the long term, the market’s positive return years have outnumbered the negative return years. Since 1926, the market has experienced a positive return in almost three-quarters of the calendar years.
• Not only are the positive years more numerous, the chart shows a larger concentration of performance in the higher ranges of returns.
• The sequence of calendar returns appears random, suggesting that accurately predicting future performance is a difficult task for any investor or professional manager.

Over time, the market has rewarded investors who can bear the risk of stocks and stay committed through various periods of performance. Therefore, the best strategy is to ignore the “noise” and stick to your investment plan.

The financial media is pleased to report that the best performing mutual fund of the decade is Ken Heebner’s CGM Focus fund.

Through the end of January, 2010, the mutual fund annualized 18.03%, easily outpacing the S&P 500’s annualized return of -0.55%.

Did you miss these returns? Not to worry, because the typical investor in the CGM Focus mutual fund also missed out on the returns. Unfortunately, there is a big difference between investment returns and investor returns.

The financial media always focuses on investment returns. In other words, what did a specific investment return? In this case, the media focuses on the great track record the CGM Focus mutual fund had over the last decade.

Of course, the media rarely focuses on investor returns. In other words, how did the typical investor perform in the same investment? Luckily, Morningstar calculates dollar-weighted returns, which represents the returns real investors receive based on buying and selling.

Here are the 10-year annualized results through the end of January, 2010:

• CGM Focus: 18.03%
• Typical CGM Focus Investor’s return: -13.73%

How can this be? How did investors lose money in the best performing stock fund of the decade?

Simple. Poor investor behavior.

Most investors make buy and sell decisions based on past performance. As the financial media was happy to point out, CGM Focus returned 80% in 2007.

Believing this trend would continue, investors poured a whopping $2.6 billion into the fund in 2008.

Then, in horror, investors watched as the fund tanked -48.2%. Disappointed with the results, investors yanked more than $750 million out of the fund.

The typical CGM Focus investor missed all the gains in 2007 and captured all the losses of 2008.

Don’t fall victim to poor investor behavior and media hype. Understand there is a difference between investment returns and investor returns.

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