Assume you had the possibility to 50% of the time manage to pick a winning trade, and the other 50% of the times a losing trade, for same profit/loss. All of the trades would be short, and in Energy futures, or any future in a commodity that would have a storage cost in the premium over spot. (future price theoretically is spot + interest rate + storage cost). Would you be able to on average make money, as you would only short and you would earn all the storage costs, which vanish into thin air anyway? (Of course sometimes you would lose big, I am assuming here you would have the possibility to make 50% good 50% losing trades, as when it comes to predicting the cash prices. I am also assuming interest rate is equal to the inflation pushing up the commodity). What do you think?