Commodity markets are volatile enough; the last thing we need is synthetic financial products making things more complicated. Commodity ETFs such as USO pool investor money to purchase futures contracts. However, a derivative of a derivative probably isn't a good idea.
Futures and Options Trading Booksby Carley Garner
What People are Saying about Our Commodity Trading Books
Choosing a Futures Broker and Brokerage Service
Full-Service or Online Trading?
The decision to trade online or through a full-service commodity broker will undoubtedly make a large impact on your bottom line.