What Is ADX?

The Average Directional Index (ADX) is a technical indicator developed by J. Welles Wilder. It measures the strength of a trend, regardless of whether the trend is bullish (upward) or bearish (downward).

• ADX values range from 0 to 100.
• A higher value indicates a stronger trend.
• A lower value suggests a weak or sideways market.
• ADX measures trend strength only, not trend direction.

To determine direction, traders use the accompanying indicators: 

• +DI (Positive Directional Indicator)
• -DI (Negative Directional Indicator)

ADX > 25 - Strong Trend

When ADX rises above 25, it signals that the market is in a strong trend. 

• Bullish Trend: If price is moving upward and +DI is above -DI while ADX > 25, the uptrend is strong.
• Bearish Trend: If price is moving downward and -DI is above +DI while ADX > 25, the downtrend is strong.
• ADX itself does not indicate direction  only strength.

Example

Example 1: Strong Bullish Trend

• A stock climbs steadily from $500 to $600.
• ADX rises to 30.
• The +DI line is above the -DI line.

This confirms a strong bullish trend. Traders may consider buying or holding positions. 

Example 2: Strong Bearish Trend

• A stock falls from $600 to $500.
• ADX rises to 28.
• The -DI line is above the +DI line.

This confirms a strong bearish trend. Traders may consider selling or shorting.

ADX Value Ranges

ADX Value	Trend Strength	Market Condition
0-20	Very Weak	Sideways/No Clear
20-25	Building Strength	Possible Trend
25-50	Strong Trend	Trending Market
50-75	Very Strong Trend	Powerful Momentum
75-100	Extremely Strong	Rare, Overextended Move

Important Notes

• ADX > 25 confirms a strong trend.
• ADX below 20 suggests a ranging or sideways market.
• ADX rising means trend strength is increasing.
• ADX falling means trend strength is weakening (even if price is still rising or falling).
• Works best in trending markets, not in choppy or sideways conditions.
• Often combined with other indicators such as MACD, RSI, or Moving Averages for confirmation.

When ADX Can Mislead

• ADX may rise during sharp volatility spikes.
• A falling ADX does not mean trend reversal it only shows weakening momentum.
• In low-volume markets, signals may be unreliable.

Proper risk management is always essential.

Final Takeaway

When ADX rises above 25, it indicates that the market is trending strongly. By checking whether +DI or -DI is dominant, traders can determine whether the trend is bullish or bearish and plan their trades accordingly. Since ADX measures strength and not direction, it should always be used alongside other indicators for confirmation.