This post focuses on customizable Double Exponential Moving Average (DEMA) factory scans, which can be edited, modified, or rewritten and then scanned using ChartAlert’s native stock screener or technical analysis scanner, namely the Basic Scanner and Advanced Scanner.

## Display **DEMA Double Exponential Moving Average** Values

Tags: dema screener, double exponential moving average, double exponential moving average formula, double exponential moving average screener, double exponential moving average strategy, double exponential smoothing

```
List symbols
Add Column DEMA(21) as DEMA chart
Apply to NSE
```

This scan analyzes and shows the 21-period Double Exponential Moving Average (DEMA) for all symbols in the National Stock Exchange (NSE). By default, the DEMA is calculated based on the closing prices.

**OPTION 1**

The Double Exponential Moving Average (DEMA) is a distinct type of moving average and should not be confused with a Moving Average of a Moving Average. The following scan provides the 21-period DEMA values and also includes an Exponential Moving Average (EMA) of an EMA for the purpose of comparison.

```
List symbols
Add Column DEMA(21) as DEMA
Add Column EMA(21,EMA(21)) as Double_EMA chart(c=blue)
Apply to NSE
```

**OPTION 2**

This scan showcases the computation of DEMA (Double Exponential Moving Average) through a straightforward representation of mathematical statements in the ChartAlert scripting language. As you review the scan results, you will observe that the resulting columns will display the same values.

The formula for calculating DEMA(21) is as follows: (2 multiplied by EMA(21)) minus EMA(21, EMA(21)). Here, “2 multiplied by EMA(21)” refers to the product of 2 and the 21-period Exponential Moving Average of the Close price, while “EMA(21, EMA(21))” represents the 21-period Exponential Moving Average of the 21-period Exponential Moving Average of the Close price.

```
List symbols
Add Column DEMA(21) as DEMA1 chart
Add Column (2*EMA(21)) - EMA(21,EMA(21)) as DEMA2 chart(panel=price, c=blue)
Apply to NSE
```

**OPTION 3**

Typically, DEMA (Double Exponential Moving Average) is calculated based on the “Close” data. However, to calculate DEMA using a different data array, such as the 14-day Exponential Moving Average (EMA) of the “Close” values, you can modify the scan as follows:

```
List symbols
Add Column DEMA(21,EMA(14)) as DEMA_of_EMA chart(c=blue)
Apply to NSE
```

**DEMA Double Exponential Moving Average Bullish Crossover**

Tags: double exponential moving average bullish crossover screener, double exponential moving average crossover scanner, double exponential moving average crossover screener, double exponential moving average crossover stocks

```
List symbols where DEMA(10) has crossed above DEMA(21) after remaining below for 3 bars
Add Column DEMA(10) as DEMA10 chart(c=red)
Add Column DEMA(21) as DEMA21 chart(c=blue)
Apply to NSE
```

This scan identifies instances where a fast moving average (10-period DEMA) has recently crossed above a slow moving average (21-period DEMA) after being consistently lower for 3 bars. The scan also provides a visual display of both the 10-period and 21-period DEMA in the output.

**DEMA Double Exponential Moving Average Bearish Crossover**

Tags: double exponential moving average bearish crossover screener, double exponential moving average crossover scanner, double exponential moving average crossover screener, double exponential moving average crossover stocks

```
List symbols where DEMA(21) has crossed below DEMA(50) after remaining above for 3 bars
Add Column DEMA(21) as DEMA21
Add Column DEMA(50) as DEMA50
Add Column DEMA(21) a bar ago as DEMA21_1 chart(c=red)
Add Column DEMA(50) a bar ago as DEMA50_1 chart(c=blue)
Apply to NSE
```

This scan is designed to identify specific instances where a shorter-term moving average (the 21-period DEMA) has recently crossed below a longer-term moving average (the 50-period DEMA) after staying below it for 3 consecutive bars. The scan also provides information on the values of the 21-period and 50-period DEMA for the current and previous bars.

**Price DEMA Double Exponential Moving Average Bullish Crossover**

Tags: price double exponential moving average bullish crossover

```
List symbols where Close crossed above DEMA(21) after remaining below for 3 bars
Add Column DEMA(21) as DEMA21 chart
Apply to BSE500.B
Apply to Sensex.B
```

This scan is designed to identify specific stock symbols (components of BSE500 and Sensex) where the closing price of a stock has recently crossed above the 21-period DEMA (Double Exponential Moving Average). This crossing should occur after the price has remained below the DEMA for 3 consecutive bars.

**OPTION 1**

To enhance the previous scan, we can modify it to also include a condition for a bullish crossover above the 21-period DEMA, in addition to higher-than-average trading volumes. It’s important to note that the expression “CHG%( DEMA(21),Close)” calculates the percentage change in the DEMA value relative to the closing price.

```
List symbols where Close crossed above DEMA(21) after remaining below for 3 bars
And Volume > Average Volume(10)
Add Column DEMA(21) as DEMA21 chart
Add Column CHG%(DEMA(21),Close) as DEMA21%
Apply to BSE500.B
Apply to Sensex.B
```

**Price DEMA Double Exponential Moving Average Bearish Crossover**

Tags: price double exponential moving average bearish crossover

```
List symbols where Close crossed below DEMA(21) after remaining above for 3 bars
Add Column DEMA(21) as DEMA21 chart
Apply to NSE
```

This scan is designed to identify NSE symbols that exhibit a specific trading pattern. It focuses on situations where the Close price of a symbol drops below its 21-period DEMA (Double Exponential Moving Average) after staying above it for 3 consecutive bars.

**OPTION 1**

To enhance the previous scan, we can modify it to also consider bearish crossovers below the 21-period DEMA, in addition to higher-than-average trading volumes. It’s important to note that “CHG%(DEMA(21), Close)” measures the percentage change in the DEMA value compared to the Close price.

```
List symbols where Close crossed below DEMA(21) after remaining above for 3 bars
And Volume > Average Volume(10)
Add Column DEMA(21) as DEMA21 chart
Add Column CHG%(DEMA(21),Close) as DEMA21%
Apply to NSE
```

For comprehensive insights into the Double Exponential Moving Average (DEMA), including its computation methodology, how to use the DEMA in trading, as well as an exploration of its advantages and limitations as an indicator, click here.