Originally written by Revolutionary FX
If you know that any trade may be a loser, you will always set a stop loss at a fair point. Sure, sometimes it will but on the occasions when it does not, you can just go on losing more and more till your broker closes out your trade because there is very little left in your account. Never let that happen! Irrespective of how powerful the signals, always set a stop loss. Sometimes our currency trading education will tell us to stick with a system through losses and gains, but infrequently, naturally, there could be a lesson to learn something from a series of losses. If you have a bad run right after starting to trade live, it may be a sign that you were not ready to go live and you are making mistakes, or your system was not adequately tested in demo.
Now and then, market behavior may change in a way that implies a system stops working for a while. Even this is an opportunity for learning. If you decide that your system might need modifying, go into demo mode or stop trading for some time and look for more fx trading education.