So I guess now we'll only have two ECN's:
INCA/ISLD
REDI/ARCA
Will this be good or bad?
A lot of people like to put an order on an ECN without a lot of stock already sitting there. That way, when the "sweeper" programs kick in, Your stock will be picked off sooner than if you were behind 5000 shares on ISLD. If there are fewer ECN's to do this with, then there might be fewer fills.
However, if you just want to take the offer/hit the bid, it'll provide larger targets.
Sure there are others, but not that significant.
They say the deal could be worth $500 million. I wonder how many billion it would have been worth 2-3 years ago?