I see quite often different robots being made to trade on any currency pair. They’re never made or even tested on all major pairs. Typically there’s just one pair and it’s created and tested on it. But traders still use it on different currencies and see absolutely different results. However, I I think it is only logical to have a robot created for one pair and trade with it on that one actual pair all the time. That’s what Forex Brilliance developers think too and they have made a suit of expert advisors that trade on specific currency pairs. There is not any perplexity as to what to trade it on and on which pair it should work better. I think more developers should use this practice.
Not only that, when you’re trading by hand you must consider that for your manual system as well . It’s a matter of chance, after you test and tweak a system on one major pair, it’s likely to perform better on it. Of course, I’m not saying that there are no systems that are universal, but it’s’s a lot more hard to develop and run such a expert advisor.