Gold has been one of the best performing assets these last two years, rising more than 40 per cent and even outpacing the S&P 500 index in the US. Long regarded as a safe-haven asset, it is traditionally favoured by those worried about the health of the global economy and financial system. However, gold has also proven to be a useful diversifier, making it a candidate for inclusion in mainstream investment portfolios. Let's discuss some of the things that can make gold prices rise and fall, then consider its investment credentials.