Play the etheric fang contract, prevent so there are several ways of blowing up:
1, set up stop-loss check surplus
2, losers big margin
3, the options
Is simply, short contract, call option; Do more contracts, put options, vice versa, if the direction of the contract, contract profit, the most to lose a couple of dollars of option of the principal, if the contract in the wrong direction, options, so you can hedge the loss of the contract, in addition to very plate, as long as a little bit big fluctuation, after open options, can realize the stable income,