DD= due diligence MM= Market Maker NITE = The name of 1 market maker THere are also ACSM AUTO ETC L2 is where you can see these guys buy and sell. L2 is level 2 and is a program where you can see a spread of buys and sells and current offers to buy and offers to sell! WELCOME to the board!!
DD = Due Diligence (research the company) MM = Market Maker (the people who run your orders from personal execution to the stock exchanges) NITE = Knight Capital Group (An MM or Market Maker...reference above)