Can someone explain, for a non-trader, what do these EMAs stand for? Why 10 and 21 and not 14 and 47? Just curious, I've been watching these averages for the past few days and the accuracy at which they predict where the prices are going next is pretty striking.
Its a moving average from the last X periods where the most recent data is weighted more heavily.
http://www.investopedia.com/terms/e/ema.asp