Cboe exchange volume per symbol inside bid and ask and top of book.
Bats uses floor trader trading system.
He created tradebot and makes between 30k and 150k a day trading a type of lightening fast arbitrage system where he picks up discrepencies in stock prices on the exchanges.
Bats electronic trading technology was designed to make trading faster and easier and it has been incorporated into products on the cboe.
The better alternative trading system bats is a u s based stock exchange offering investors equities options and foreign exchange trading services.
Bats global markets originally began as an alternative exchange and is now part of the cboe one of the largest exchange operators in the world.
Bats global markets was a global stock exchange operator based in lenexa kansas with additional offices in london new york chicago and singapore bats was founded in june 2005 became operator of a licensed u s.
Trading in the debt instruments through its bond automated trading system bats.
I have not used bats but i have read all about dave cummings.