If someone is using discretionary techniques to trade, how do they know if they have a positive expectancy? I'm thinking that they get on a simulator, practice their technique to ensure that they generate money, and then apply the same technique to the real market.
Does this mean that when the market changes, your technique will have to change and you'll have to get on a simulator again?
Is there any other way besides this to check for positive expectancy?
PS: I have been out of the "trading game" for some time, so I'm sorry if this is a stupid question