Small-cap core and value mutual funds have done a much better job than growth in outperforming the large-cap oriented S&P 500 in the past 15 years. An investment of $10,000 in the average small-cap value fund on Sept. 30, 1999, would have grown to $55,013 by Nov. 11 this year, according to Morningstar Inc. data. The same amount in the average small-cap core fund, which invests in both growth and value stocks, would have yielded $54,042.