EMA returns the Exponential Moving Average of the specified period.
EMA is similar to Simple Moving Average (SMA), in that it averages the
data over a period of time. However, whereas SMA just calculates a
straight average of the data, EMA applies more weight to the data that
is more current. The most weight is placed on the most recent data point. Because of the way it's calculated, EMA will follow prices more closely
than a corresponding SMA.