If your free margin drops to zero, your broker will send you a margin call in order to protect the used margin on your account. Always monitor your free margin to prevent margin calls from happening, and calculate the potential losses of your trades (depending on their stop-loss levels) to determine their impact on your free margin. With some experience, you’ll find it significantly easier to follow your margin ratio and understand the meaning of margin in Forex trading.
Back tests – You can read my forex robot reviews to see if the forex robot has back tests which will give you a good idea how it performed historically, some forex robots even back test as for as 15+ years! Ideally, you would want back tests to have been done using real tick data and spreads, thus making the forex robot back test results as accurate as possible in the mt4 strategy tester