Bollinger Bands mid line


Dear Tomasz;
good evening.
The inbuilt Bollinger band chart shows the top and bottom curves but the mid line is missing.
As per Mr. Bollinger 9Inventor): Bollinger Bands consist of:

an N-period moving average (MA)
an upper band at K times an N-period standard deviation above the moving average (MA + Kσ)
a lower band at K times an N-period standard deviation below the moving average (MA − Kσ)

So like to know how to make mid line in the chart.

Same is with Keltner band also.
Please advice.


@rao, the middle line is a simple moving average with the same N-period of the Bollinger Bands® .

Typically, in AmiBroker, you will build your chart inserting a the price plot, (then overlay the MA if not altready present in the price formula), then overlay the BB setting the N-period for the MA and the BB at the same value. Here a more detailed description of these volatility bands.


Thanks for the reply.