In our world , everything is relative , so we should not believe in everything 100% . And it is true for indicators . No have any indicators can give us 100% signals . This is the reason why we need to combine some indicators to get the more exactly signals .
From my point of view it is hard to say what could happen if you trust one indicator 100 % because I also follow fundamentals, however I think results might not be as good as you might expect and winning/losing ratio of 50 % would be great if you achieved I think.
I think that all indicator are the data in past time that has been calculated and used to predict future prices, so it is not always an indicator that makes a prediction right, there is no 100% accurate indicator
so we should try yourself so that we can contribute in here to gain a best position in here
Indicators helps us to develop a strategy,and to analyze the forex market to determine whether the conditions for a profitable are good. But it still empirical,nothing is sure.
i am an experienced trader till now i have never found any software or system or any indicator which is 100% accurate in forex trading.Some of them are accurate but to a limit maximum accuracy you can gain in market i think is just 80%.
I think that you are absolutely right that in here all of the indicator can not make profit all the time and it may be excellent at some times and very bad at some times also too and finally you loss your capital in here so i think you should learn more in here and increase your skill and make sure your profit without any kind of loss in here.