Bollinger Band Moving Average

The Bollinger Band Moving Average Indicator overlays the Price Chart. It consists of three lines, two of which (the Top and Bottom) are plotted at a standard deviation from a Simple Moving Average A single line that is calculated from the average Close price of a security over a specified number of days. – the Middle line. The standard deviation, specified through the NumDeviation parameter (see below) is a measure of volatility A statistical measure of the tendency of a market or security to rise or fall sharply within a short period of time.; the Top and Bottom lines adjust to market conditions, widening during volatile market periods and contracting during less volatile periods. By default, the standard deviation is +/- 2 the Simple Moving Average of 20 days. You can change each of these parameters.

Indicator Properties

Parameter	Description
TOP	The color of the (Top) line representing the standard deviation above the Simple Moving Average.
BOT	The color of the (Bottom) line representing the standard deviation below the Simple Moving Average.
MID	The color of the (Middle) line representing the Simple Moving Average.
Periods	The number of rolling periods [e.g., Historical (days), Intra-day (minutes, hours, etc.)] considered in the average calculation. The default value is 20.
NumDeviation	The standard deviation +/- the Simple Moving Average. The default value is 2.