i am pretty sure the big dow (25) *is* fungible with the mini dow (5).
this would offer the same opp that the original trader desired, in terms of commissions saving - they would be very nice
consider that if you buy 2 big dows (equivalent of 10 minis) you pay about $4 to be long 10 contracts vs. $20. that is a MAJOR commissions savings
the problem is that commission is only really a big issue when you are scalping. if you are going for 3-8 points or so, it's much more significant than if you are going for 15+
and since the big dow has such terrible spread, it's non scalpable
i am also pretty sure that the big dow is fungible with the mini through IB. not 100% sure though
