Between 2000 and 2007, the index outperformed many of its Western peers, driven by relatively strong domestic economic growth which particularly helped construction and real estate stocks.

That came out of a month in which the index easily outperformed the Dow by rising 11 percent in May, its best monthly showing in a decade.

Since 1991, the index has outperformed other popular indexes such as the S&P 500 and Dow Jones Industrial Average by about 10 percent.

From that point, the index would outperform the money market by 50 basis points, or hundredths of a percentage point, a quarter - a significant amount in the bond world.

In 1988, the Amex's index outperformed the other gauges, posting a 17.5 percent annual rise.

The index has outperformed the S.& P. 500 since its start in 1993.

But over the last five weeks, both indexes have outperformed their more famous brother.

According to S.&P. data, an equal-weighted 500 index would have outperformed the cap-weighted version by 1.3 percentage points a year, on average, since the beginning of 1990.

The index outperformed 93 percent of equity funds through May.

Since then, small and middle-capitalization indexes have outperformed the "nifty fifty" large-capitalization stocks.