Actually, it IS just one big distributed exchange since Reg NMS requires each ATS to route an order to a rival with a better price.
This is good, because new ATS's dont need to worry about network effects and can compete on features.
On the other hand, this required functionality could limit the set of possible new features. For example, it may be difficult to implement some way to discretize or slow down markets to remove any unnecessary advantages conferred on HFT traders, because of this mechanism.
This is good, because new ATS's dont need to worry about network effects and can compete on features.
On the other hand, this required functionality could limit the set of possible new features. For example, it may be difficult to implement some way to discretize or slow down markets to remove any unnecessary advantages conferred on HFT traders, because of this mechanism.