These ETF's are really just for day trading or holding for a month at most. In December the ETF was getting too low so they did a 5 for 1 reverse split. When they change to the next months contract, if the next month oil is more than the current months oil, the ETF can't buy as much oil. So that will erode the value. They also reset everyday after the close. Even if the price of the commodity stays the same the ETF will loose money because of the daily reset and fees. I hope this helps, I'm not the best at explaining things. All I know if I were to play these again I would use stops if you don't you are asking for trouble.