What is the benefit of maintenance margin?

By using funds from your available balance to buffer the trade, the maintenance margin helps to increase your level of protection during times of market volatility, when prices can swing up and down by large increments. With this feature, you will never lose more than you have invested in a single trade.

Therefore, in the event that you set your Stop Loss to 100% of the invested amount and there is a sudden market spike, you may lose more than you originally invested.