More impressively, the price of gold has outperformed the S&P 500 Index so far this century, returning 86 percent more than the market if we index both asset classes at 100 on December 31, 1999. Over the past 17 years, the S&P 500 has undergone two major contractions, both of them resulting in a loss of around 40 percent. Gold, meanwhile, has held its value well, boosting its appeal as a portfolio diversifier.