Small-cap mutual funds gained 8.35%, making them the top performer in U.S. stock funds, according to Standard & Poor's. In fact, small-cap funds of all types far outperformed other cap stocks. The best performer among large caps was the Large-Cap Blend at 3.23%, while the Mid-Cap Growth was tops in that category, posting 6.22%. Domestic Equity funds started off the year with 4.76% by the end of January. S&P mutual funds strategist Rosanne Pane predicts "mid- and small-caps will continue to lead returns over the short term, as recent earnings disappointments have been in the large-cap arena." The S&P 500-Stock Index rose by only 2.65% last month.