How to Add ADX Indicator in MT4 Charts - Adding MT4 ADX CFDs Chart Indicator
Step 1: Open Navigator Window Panel on CFDs Trading Software
Open Navigator window panel as illustrated below: Navigate to 'View' menu (click on it), then select 'Navigator' window panel (click), or From Standard Toolbar click the 'Navigator' button key or press keyboard shortcut key 'Ctrl+N'
On Navigator window, choose 'Technical Indicators', (Double-Click)

How to Add ADX Indicator in MT4 - MT4 ADX Technical Indicator
Step 2: Expand the Indicators Menu on the Navigator - Adding ADX MT4 Chart Indicator
Expand the menu by clicking the expand button marker (+) or double click the 'indicators' menu, after this the button will appear as (-) and will now display a list as shown below - select the ADX cfds chart indicator from this list of cfds indicators so as to add the ADX indicator on the cfd chart.

How to Add ADX Indicator - From the Above window you can then place ADX indicator that you want on the CFDs chart
How to Add Custom ADX Indicator to MT4
If the technical indicator you want to add is a custom indicator - for example if the ADX technical indicator you want to add is a custom indicator you will need to first add this custom ADX indicator on the MetaTrader 4 software & then compile the custom ADX indicator so that the newly added ADX custom indicator pops up on the list of custom indicators in MetaTrader 4 software.
To learn how to install ADX indicators on MT4, how to add ADX indicator window to MT4 and how to add ADX custom indicator in MT4 - How to add a custom ADX indicator in MT4.
About ADX Technical Indicator Explained
ADX Technical Analysis and ADX Trading Signals
Developed by J. Welles Wilder
This a momentum indicator used to determine the strength of a price trend: it's derived from the DMI - Directional Movement Index which has 2 lines.
+DI - Positive Directional Movement Index
–DI - Negative Directional Movement Index
ADX is calculated by subtracting these 2 values & applying a smoothing function.

The ADX isn't a directional technical indicator but a measure of the strength of the trend which has a scale of Zero to 100.
Higher the technical indicator value the stronger the trend.
A value of below 20 indicates that the market is not trending but heading in a range.
A value of above 20 confirms a buy or sell signal & indicates a new trend is emerging.
Values above 30 indicates a strong trending market.
When ADX indicator turns down from above 30, it indicates that the current trend is losing momentum.
ADX combined with DMI - Directional Movement Index Indicator
Since the ADX alone is a directionless indicator it is combined with the DMI index to figure out the direction of the cfds pair.

DMI
ADX & DMI Index

When the ADX is combined with DMI index a trader can determine the direction of the trend and then use the this indicator to determine the momentum of the prevailing trend direction.
CFDs Technical Analysis and Generating Trading Signals
Buy Trading Signal
A buy trading signal is generated when +DI is above –DI, and the ADX technical indicator is above 20
The Exit signal is generated when indicator turns down from above 30.

Buy Trading Signal
Sell Trading Signal
A short signal is generated when –DI is above +DI, and the ADX technical indicator is above 20
The Exit signal is generated when indicator turns down from above 30.

Sell Trading Signal


