Health care mutual funds have outperformed the S&P 500 by a wide margin in the past 15 years and have really taken off the past two years. You’d be sitting on $48,522 today if you’d invested $10,000 in the average health care fund on Sept. 30, 1999, according to Morningstar data. The same investment in the S&P 500, which tracks the broad stock market, would have grown to $21,149.