The graph shows the balance each time an order is closed, but take into account that it is when an operation close. That is, balance materialized, it does not mean that the floating has not been lower.
Soon in tradEAsy, you will also see the floating balance, which means you could configure the maximum loss, even in the period in which an order has not been closed.
As an alternative, in metatrader4 you can make simulations analysing the floating of the opened orders. If you are going to work simulations in metatrader4, you may upload high-quality data to make sure the reliability of the results. In tradEAsy we offer them here.
