Kevin,
I think you mentioned in another post that market makers at IB's IdealPro do not have to honor their bid/asks..
is this really so? What are the technicals of this? How long do they have to withdraw a bid after an order has been placed against it?
I understand that EBS's platform requires all bid and asks to remain active for at least 2 or 3 seconds for the explicit purpose of allowing manual trades to be made in time against them. Without this, they would lose much of their (manual) business.