Commodities as an investment haven’t done well in recent years, but this year has been especially bad. They’ve been the worst-performing asset class in 2014, with a return of -16% year-to-date. Barring a rebound in the next month and a half, that would be their worst performance since the financial crisis in 2008. So is the pain now over for investors with exposure to commodities? The answer depends on the key factors that have driven down commodity prices.