It seems as though my order waits until the ECN is gone, then executes with the MM. Is this how it's supposed to work?
For SuperSOES, yes, this is how it is supposed to work. ECN's are not SuperSOES'able. None of the ECN's have chosen to participate in the SuperSOES program, and therefore, if only ECN's are available at the inside market, you will not be able to execute a SuperSOES order until they are gone.
Most daytrading platforms, however, have some form of intelligent order routing. For example, on RT3 you have the ARCA order routing option. These systems automatically route your orders to a combination ECN's and/or MM's to fill your order quickly and efficiently. Now, with the SuperSOES system implemented, these intelligent order routing systems are much better and faster than ever.
Good luck, -Eric |