# BBF (Bollinger bands flat)

Bollinger bands flat indicator provides the same data as Bollinger bands but is displayed in a separate field and thus makes it easy to determine whether prices are in or out of the band.

This indicator consists of:

* Positive deviation – shows the value of the positive standard deviation, shifted N times up;
* Negative deviation – shows the value of the negative standard deviation shifted N times down;
* Delta – shows the difference between the current value and the value of the moving average at a given point. 

## Calculation

As can be understood from the above, only three components of the indicator are calculated:

Delta = ClosePrice - MA, where

ClosePrice is the current value of the Close price,

MA - the value of the moving average.

Positive deviation = A \* D, where

A - deviation parameter value,

D - dispersion relative to the moving average,

Negative deviation = (-1) \_\_A \* D

## Main parameters

* Period – provides the ability to set the number of confidence intervals, 20 by default;
* Deviation – for setting the required deviation, 2 by default;
* Type of Moving average – moving average calculation type: Simple, Exponential, Modified, Linear weighted;
* Data type – type of price at which the indicator will be calculated: Close, Open, High, Low, Typical, Medium, Weighted.

This looks as follows on the chart:

![](/files/-MgF4OQ0Yrsi08qlsb_q)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://help.za.velocitytrade.com/mobile-applications/ios/phone/technical-indicators/channels/bbf-bollinger-bands-flat.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.