Moving Average Envelope

MovingAverageEnvelopeTop(Periods, MA Type, Shift) or
MAET(Periods, MA Type, Shift)

MovingAverageEnvelopeBottom(Periods, MA Type, Shift) or
MAEB(Periods, MA Type, Shift)

Overview
Moving Average Envelopes consist of moving averages calculated from the
underling price, shifted up and down by a fixed percentage.

Interpretation
Moving Average Envelopes (or trading bands) can be imposed over an actual price or another indicator. When prices rise above the upper band or fall below the lower band, a change in direction may occur when the price penetrates the band after a small reversal from the opposite direction.

Recommended Parameters
Periods: 20
MA Type: SIMPLE
Shift: 5

Example
set BUY = CLOSE > MAET(20, SIMPLE, 5)
Evaluates to buy when the close is greater than a 20-day Moving Average
Envelope Top calculated by 5% using a simple moving average.