Hedge funds are making the biggest bet ever against gold prices, signaling continued volatility for the metal after prices entered a bear market last month. The CHART OF THE DAY shows that gains in so-called short contracts are usually followed by increases in a gauge of price swings for the SPDR Gold Trust, the biggest bullion-backed exchange-traded fund. Yesterday, the value of the SPDR Gold ETF climbed as much as $1.5 billion before ending the day down $418 million. Bullion has tumbled 18 percent this year as some investors lost faith in the metal as a store of value and amid concern that the Federal Reserve may ... (full story)