Currency: SUM(loss * quantity * point value) of all losing trades / # of losing trades 

Percent: SUM(profit * quantity / entry price) of all losing trades  / # of losing traded lots

Points: SUM(profit * quantity) of all losing trades / # of losing trades

where loss is defined as (exit price – entry price) for long trades and as (entry price – exit price) for short trades, and point value  is defined as the monetary conversion of each point (e.g. 100 for currency pairs).

This statistic returns a value representing the average loss you experience from all of your losing trades. It is useful for getting an idea of how much you could expect to lose on losing trades.