What do the different colors represent?
The colors are a visual that enables you to better determine how many market makers, or ECNs are on the Bid or Ask at a particular price. You can change the display colors using the Market Maker Setup window - Colors & Fonts tab.
How can you tell the difference between a market maker and an ECN?
There are currently 10 ECN's - ARCA, ATTN, BRUT, BTRD, INCA, INET, MKXT, NTRD, REDI, and STRK. All the other four-letter symbols represent market makers.
What is an ECN?
An ECN (Electronic Communications Network) is a system for matching buys and sells without market maker intervention.
Does the number under the Size column need to be multiplied or is that the actual volume the market maker or ECN is there for?
The number is displayed in lots and must be multiplied by 100 for the actual volume.
What does the exchange letter in the Level I view (the upper right-hand corner of the Level II View) represent?
This letter represents the Exchange ID for the stock being traded.
On the Level II View Trade Ticker, why are some entries red and some entries green?
A red entry means the trade occurred on a down tick. A green entry means the trade occurred on an up tick.