Nov 20, 2019 · Your position size, or trade size, is more important than your entry and exit points when day trading foreign exchange rates ().You can have the best forex strategy in the world, but if your trade size is too big or small, you'll either take on too much or too little risk. The former scenario is more of a concern, as risking too much can evaporate a trading account quickly. What is Margin Level? - BabyPips.com Margin Level is very important. Forex brokers use margin levels to determine whether you can open additional positions. Different brokers set different Margin Level limits, but most brokers set this limit at 100%.. This means that when your Equity is equal or less than your Used Margin, you will NOT be able to open any new positions.