What is Position Size? Why is it important for professional traders? One of the keys to survival in the Forex market is not finding the most accurate trade entry signals... But it is risk management — And the heart of risk management is calculating the appropriate Position Size. What is Position Size? Position Size is the number of “lots” you open a market order for. which has a direct effect on Size of profit/loss per price movement Risk to the portfolio on each trade. Simpl