I watch and trade 16 currencies, I'd be lost without all 16 on my screen at once. Sometimes for example no market is moving on M1 and USDSGD suddenly breaks, and so so long as I have a fundamental thesis for the trade and am in agreement I go long GBPUSD, the riskiest risk currency (because the BoE rate is so low, among other things), for example. Often then it'll pop, the Singapore dollar having already popped a few moments earlier.
You can specialize with one currency I know some better than others when it comes to trading but you should be lost if you don't have at least EURUSD USDJPY GBPUSD EURJPY USDCAD USDCHF AUDUSD EURCHF and perhaps USDSGD open on your screen, the rest is contextual, take the example of my last trade, if I thought oil was cheap and the BoE was inclined to do more QE maybe I would have gone short USDCAD instead of GBPUSD.
You can specialize with one currency I know some better than others when it comes to trading but you should be lost if you don't have at least EURUSD USDJPY GBPUSD EURJPY USDCAD USDCHF AUDUSD EURCHF and perhaps USDSGD open on your screen, the rest is contextual, take the example of my last trade, if I thought oil was cheap and the BoE was inclined to do more QE maybe I would have gone short USDCAD instead of GBPUSD.