To be properly diversified, portfolios should have some allocation to Gold since the metal acts differently compared to other market influences. Gold is at an all time high so best to average in. That is, decide how much you want (5% to10% of the portfolio may be appropriate) and buy over a period of several months just in case there is a pullback in the short term.
An investment in gold will protect against political uncertainties, inflation, and higher demand form India and China. There are two ways to buy gold cheaply: one is through the ETF symbol GLD which is a pure investment in Gold, and also in another ETF symbol GDX which is an investment in a basket of gold mining stocks. Buy both.