Quote from trade-ya1:
My guess is that IB is showing the actual Globex (?) electronic market session. Refco is probably running an internal system as they are market participants as well. My guess is that when you get filled through Refco the other side of the trade is Refco. When you get filled through IB, it is the actual electronic market that is filling you. I'm not too sure about these issues however, I mostly trade the spot and futures utilizing EFPs (Exchange for physical).
