Definition:
DBO, the PowerShares DB Oil ETF, tracks the price performance of the Deutsche Bank Liquid Commodity Index - Optimum Yield Oil Excess Return. The index consists of futures contracts on Light Sweet Crude Oil (WTI) and also reflects the price and performance of crude oil.
If you'd like to see more related funds, here is a thorough list of oil ETFs and ETNs. A List of Oil ETFs
Or if you are more interested in energy investments, here is a List of Energy ETFs.
