larry, if people do not place their order in the buy/sell queue then how could you see it in market depth.
A lot of buyers/sellers simply buy or sell at the market price at the time, so their orders are executed as soon as they place them and never register in the market depth for more than a split second anyway.
This means that market depth is sometimes not a good indicator of support for a stock.
Also sometimes large buy or sell orders are placed in the market depth to make it look like there is a lot of interest in buying or selling a stock, but these orders are pulled before they are executed. It is easy to manipulate market depth to fool the gullible into buying or selling.
