ENV(values; period; shift)

The 'values' argument must be an array.
The 'period' defines the period for the function - it must be a constant greater or equal to 1.
The 'shift' defines the offset from the simple moving average of 'values' in percents. For the upper band this must be a positive value and for the lower band - a negative value.

The result is an array. The first 'period' elements of the result are marked as invalid.

Price envelopes are plotted at a specified percentage above and below a moving average. They are used to indicate overbought and oversold levels. The shift percentage should be set so that about 90% of price activity is contained within the bands. Adjust the band width if volatility increases over time.

Windows Forms: All Examples\Data Manipulation\Functions\Financial\Range Indicators