Reply to post: "well-known to be using exploits in the trading systems,"

"well-known to be using exploits in the trading systems,"

These are not exploits.

They rely on the use of special order types.

With a separate order sent on every share being traded.

How the exchange responds to this order tells the organization sending the order IE the HFT company,

These are not real orders.

They are in effect "pings" to the market to detect what is going on.

Apparently there are 150 order types supported by some (if not all) exchanges. These order types would not exist without the express support of the exchanges involved.

Once you're read "Flash Boys" you realize, this is no accident.