Eric...people tell me you're the man wrt figuring out best broker (looking for direct access, coupled with L2 or 3, not that I really know what L3 will do for me)...I currently use Schwab, but getting beaten up a bit on fills and the like...otherwise dependable as heck...some have suggested MyTrak, Executioner, CyberX, MBTrading and others...I've been to a number of sites on SI to do research, but all roads seem to lead here!!
Although there are many good direct access brokers for active traders, I would stick with a Real Tick III firm and personally prefer The Executioner (http://www.executioner.com). Real Tick III firms use data feed and software from Townsend Analytics, the worlds leader in this market. There are certainly a number of very good Real Tick III firms, but I really like the people at The Executioner and feel that they are on the cutting edge of new technologies for their customers.
Regarding Level 2 and 3 data. Level 2 data can be very useful for short term traders, while Level 3 screens are not even available to them. A Level 3 screen is used by market makers to accept and fill SelectNet and/or SOES orders using their direct Nasdaq connection. Level 3 screens are not relevant or available for the individual trader.
Good luck, -Eric |