Envelope - Another indicator that is very similar to bollinger bands is the Envelope.

We use the Envelope the same way as bollinger bands.

The difference is the Envelope is an indicator which is a compilation of moving averages rather than bands using standard deviation.

Both moving averages calculate the security price using the same time frame period.

The only difference is the location are shifted so that one line located above the security price, and one is located below.

This creates boundaries of a securities normal trading range.