A true national market system would have the following property. There are clearly defined points of entry to the system: that is, when an order is placed on specific exchanges, ECNs or ATSs, they will count as part of the system. These orders are time-stamped by a perfectly synchronized process. In other words, it doesn’t matter where your point of entry is, the time-stamp on your order will put it in the correct order relative to every other part of the system.
Order matching engines are, then, required to take the time to check that time-priority is respected across the national market system as a whole.
This structure would eliminate many of the nefarious aspects of speedy trading, while at the same time allowing high-speed traders to provide liquidity within the constraints of a strictly time priority system. Speedy orders couldn’t step in front of existing orders, because time-priority would be…
View original post 128 more words