PwC wrote:In fact, over a five-, ten-, and twenty-year basis, gold has provided one of the best diversifications against stocks, with a correlation of 0.04, -0.05, and -0.07 respectively. ... In addition to being a hedge against crises, gold outperformed all traditional asset classes on a ten- and twenty-year basis, with annualised returns of 6.7% and 6.8% respectively, making it an important consideration for long-term investments.
The above is from the executive summary; a more detailed section on gold begins on page 29.