So using the example above. You lost USD 10,000 and you get USD 10,000 Credit that you have to earn out. You happen to face bad luck and a series of bad trading decisions. Instead of earning USD 10,000, you actually lose USD 2000 more. The next month, the USD 2000 is credited given the period to earn back the USD 10,000 has lapsed and now you have a chance to earn back USD 2,000.
