I boldly stated that buying and holding all the stocks in a broad, stock-market average—as index funds do—was likely to outperform professionally managed funds whose high expense charges and large trading costs detract substantially from investment returns.

Now, some thirty years later, I believe even more strongly in that original thesis, and there's more than a six-figure gain to prove it. The chart on the following page makes the case with great simplicity. It shows how an investor with $10,000 at the start of 1969 would have fared investing in a Standard & Poor's 500-Stock Index Fund. For comparison, the results are also plotted for a second investor who instead purchased shares in the average actively managed fund. The difference is dramatic. Through June 30, 1998, the index investor was ahead by almost $140,000, with her original $10,000 increasing thirty-one-fold to $311,000. And the index returns were calculated after deducting the typical expenses (2/10 of 1 percent) charged for running an index fund.