Trade Plan is to define which stocks needs to brought/sold, which instrument to be used, what is the margin( to understand the risk) and when to exit. It is essential to understand and minimize the risk and monitor the market movement to the plan to determine the exit.If we buy a stock expecting the price of the share to go high then is said to be creating long position. On the contrary if we sell a stock expecting the price to go down it is called Short Position.Selling the stock that is already bought is long unwinding and Buying a stock that has been already sold is Short covering.