SCO, the UltraShort DJ-AIG Crude Oil ProShares ETF, acts as an inverse ETF by tracking twice the daily performance of the Dow Jones AIG Crude Oil Sub-Index. If the underlying index rises, this oil ETF will decrease.
If you'd like to see more related funds, here is a thorough list of oil ETFs and ETNs.
If you'd like to see more inverse ETFs, here is a thorough list of inverse ETFs and ETNs.
Or if you are more interested in energy investments, here is a List of Energy ETFs.

