Quote from bevo96:
This is one of the most uninformed, idiotic statments I have ever read. Flash orders no longer exist anywhere except Direct Edge and the buy side traders choose to use them with hopes of price improvement.
Funny how it's always the ad hominem jerk who makes the most uniformed statements.
This is true for exchanges, but not dark pools. Dark pools use all sorts of different flash messages. The exact details vary. Sometimes they will give a price and a buy/sell indication, allowing the firm to take the other side. Sometimes they will give a price without a buy/sell indication and allow the firm to join either side. Sometimes, such as in the Getco dark pool, the order flow data remains private to Getco only. Other pools actively recruit "market makers" who trade for free and get flash quotes from the pool. Furthermore, if you look at a flow chart of some of the large execution services (like Redi Sigma X, or Knight execution) each order will make at least 5, usually more, stops BEFORE the trade ever hits a public exchange.
I have spoken with management of a proprietary options trading copany in Chicago that makes markets on dark pools, which gives them edge and information. They then lay off their positions as customers in public exchanges, where they get paid for their order flow. They literally quote each option half a penny wide, and trade huge size, though the only liquidity they provide comes from the public exchange market makers that they are canabalizing.