trading with Interactive Brokers: suppose I have a position in ym and globex goes down. If I want to hedge my ym contracts with the pit-traded dow contracts (indu), do i need additional funds in my account to pay margin for these pit-contracts? what i´m doing is neutralizing my risk, so it wouldn´t seem logical. For example if I am long 2 ym-contracts, globex goes down and I hedge my position going short one indu-contract (one indu equals two ym), margin requirement should actually go back down to zero. is this the case?