What is challenging part of trading? Why someone close day in loss even after a couple of successful trades?

The answer is very simple and clear. A trader needs to set rules about when to close trading for the day regardless of profit or loss.

Why we saying regardless of profit or loss. Over trading destroy account even if you have best forex forecast or accurate trading signals.

Excess of everything is bad, controlling your trading activity is equally important to generate the accurate trading forecast. You can have best forex signals but it won’t be that useful until you set rules of not over trading.