There are lot of currency pair in forex market. But I prefer to trade in major pair like EURUSD, GBPUSD, USDJPY. They are quite volatile than other currency pair. Moreover, my broker Tpglobalfx provides low and tight spread in major pair. I am scalper, So, I need low spread for my trading strategy. However, trader should trade in all pair. Mastering one or two pair is enough to become successful.