amateurs should not be allowed to invest, page-7

all I am trying to say is that it is generally far better to set a price at which to sell or buy, and wait to see what transpires over the course of the day, rather than costing yourself money by placing "at market" orders that either drive the price up or down unnecessarily. Unless their is an urgent need to get out or in. otherwise it just costs you money and greatly diminishes the return that you would otherwise make.

It is a basic lesson for share investment