Emerging-market stock mutual funds are clear performance winners over the broad stock market in the past 15 years. A $10,000 investment made in the average emerging-market fund on June 30, 1999, would have growth to $37,386 by Sept. 19 this year, according to Morningstar data. The same investment in the S&P 500 would have grown to only $19,502. But the S&P 500 has been catching up, rising 10% year to date vs.