That depends on your time zone. And what you can want to trade. You can see that currencies such as eur / usd perform well in most seasons because when the European season sleeps, US traders start trading it so that it is one of the best pairs to trade and pair up like aud / jpy moves well in one season. and we have to know and learn all of them, they have their own functions I am a scalper but I use all the time frames and that makes me get more information..and this is important for my trade, and I think that is a wrong concept if we use one of them as a favorite if you think of low marginal profit in a short time and want a low risk free trade then go for a period of 15 minutes. On the other side