The chart below provides an excellent visual on the four years of commodity pain. After out-performing the rest of the commodity space over the last two years, oil has "caught down" to the rest of the crowd. As readers know I've been a steady buyer of precious metals and agriculture over the last 18 months and following the recent carnage in the oil market I've become a buyer in that space as well.
See: Oil Price Collapse: Buying Opportunity?
In those three markets prices are low, sentiment is catastrophic and long term fundamentals are incredible. It doesn't happen often when you get all three to align as it did with Chinese stocks back in late 2012 (unfortunately the Chinese market is now about 37% higher and positive sentiment has returned).
See China's Stock Market Continues To Plunge: Buying Opportunity?