# Technical Studies Reference

- Technical Studies Reference
- Common Study Inputs (Opens a new page)
- Using Studies (Opens a new page)

# Bands/Envelope

### Description

This study calculates and displays Bands based on the **Input Data**. The Bands are referred to as the Top Band and Bottom Band, and they are drawn, respectively, above and below the Main Price Graph.

Let \(X\) be a random variable denoting the **Input Data**, and let \(X_t\) be the value of the **Input Data** at Index \(t\). Let the Input **Percentage/Fixed Value/Ticks** be denoted as \(v\). Then we denote the values of the Top Band and Bottom Band at Index \(t\) for the given Inputs as \(TB^{(E)}_t(X,v)\) and \(BB^{(E)}_t(X,v)\), respectively. The methods of calculating these values depends on the value of the **Bands Type** Input. We describe each method below.

** Bands Type = Percentage**:

The

**Bands**are drawn above and below the Main Price Graph by a Percentage of the

**Input Data**. If the Percentage is to be 5%, then a value of \(v = 0.05\) should be entered.

\(TB^{(E)}_t(X,v) = X_t + X_t \cdot v\)

\(BB^{(E)}_t(X,v) = X_t - X_t \cdot v\)

** Bands Type = Fixed Value**:

The

**Bands**are drawn above and below the Main Price Graph by a Fixed Value \(v\).

\(TB^{(E)}_t(X,v) = X_t + v\)

\(BB^{(E)}_t(X,v) = X_t - v\)

** Bands Type = Number of Ticks**:

We denote the Tick Size as \(s\), and it appears as a third argument of the

**Band**functions. This value is set through

**Chart >> Chart Settings >> Main Settings**. The

**Bands**are drawn above and below the Main Price Graph by a Fixed Value \(v \cdot s\). With this Band Type, the band functions have an extra parameter, \(s\).

\(TB^{(E)}_t(X,v,s) = X_t + v \cdot s\)

\(BB^{(E)}_t(X,v,s) = X_t - v \cdot s\)

#### Inputs

- Input Data
**Percentage/Fixed Value/Ticks**: This Input sets the Percentage, where 1 percent is .01, to multiply the**Input Data**by. Or sets the Fixed Value to add or subtract from the**Input Data**.**Bands Type**: Sets the bands type to either a**Percentage**,**Fixed Value**, or**Number of Ticks**.

#### Spreadsheet

The spreadsheet below contains the formulas for this study in Spreadsheet format. Save this Spreadsheet to the Data Files Folder.

Open it through **File >> Open Spreadsheet**.

*Last modified Tuesday, 31st January, 2023.