Forex data vary from one provider/ECN/MM to another. Traders that hit a stop in one seris from one provider do not in another and vis versa. So you must know what you are doing and also know that you must know what you are doing.
always we are making backtest.... but the price doesnt care with this backtest.. because when you make back with the bar and find some of the point out of your indicators you soon modify them to make the price icluded... that will be in the past area.. and you say now it is good i will go ahead it is ok... but when you start you will find another point which causes losses... and you going to modify again... the price doesnt confess with pack test ... it confesses with it self... there is nothing will rule the price...else your tichnical analization. but you can depend on the indicators to see where you are... get the situation of the price by them ,, analyze,,,, but your TRGT,,,and get your pips.... lets imagine that we got an expert indicator and made a backtest... and we found it good.... and all the traders have started to use it.... and opened the same kind of position.. do you think that the price will go ahead as well as the traders wish ??