ADX measures how strong a trend is, regardless of direction. Pick a pair below and get its live ADX reading with an instant interpretation of what the number actually means.
The Average Directional Index (ADX) is a technical indicator that measures the strength of a trend. It was developed by J. Welles Wilder Jr. and introduced in his 1978 book New Concepts in Technical Trading Systems. ADX reads on a scale from 0 to 100. The higher the number, the stronger the trend.
The single most important thing to understand about ADX is what it does not tell you. ADX does not tell you direction. It does not say whether price is going up or down. It only tells you whether a trend exists and how strong it is. A market crashing hard and a market rallying hard can both produce the same high ADX reading.
The one-line definition: ADX measures trend strength, not trend direction. A high ADX means a strong trend is present. It does not tell you which way that trend is pointing.
ADX is interpreted by where it sits on its scale and, just as importantly, by its slope. A rising ADX means the trend is strengthening. A falling ADX means the trend is weakening, even if the value is still high.
| ADX reading | What it means |
|---|---|
| 0–20 | Weak or no trend. The market is ranging or consolidating. |
| 20–25 | Ambiguous. A trend may be forming but is not yet established. |
| 25–50 | Strong trend. Trend-following approaches find their edge here. |
| 50–75 | Very strong trend. Powerful directional momentum. |
| 75–100 | Extremely strong trend. Rare, and often near exhaustion. |
The widely used threshold is 25. Above 25, most traders treat the market as trending. Below 20, the market is treated as ranging. The 20 to 25 band is the grey zone where a trend may be forming but has not confirmed.
ADX never travels alone. It is the headline line of a larger system Wilder called the Directional Movement Index (DMI). The DMI has three lines: ADX itself, plus two directional indicators that do tell you direction.
This is how you recover direction. When +DI is above −DI, upward movement dominates. When −DI is above +DI, downward movement dominates. ADX then tells you how strong that dominance is. The live tool above shows all three so you can read both strength and direction at once.
ADX is most useful as a filter, not a trigger. It does not generate entries on its own. It tells you which kind of strategy is appropriate for current conditions.
Trend-following approaches are favoured. Momentum signals, breakouts, and moving-average strategies tend to perform when ADX confirms a strong trend. Counter-trend and mean-reversion setups fight the prevailing force and tend to fail.
Mean-reversion approaches are favoured. Buying near support and selling near resistance works when there is no strong directional momentum. Breakout strategies produce false signals because moves do not follow through.
The common mistake: using ADX as a buy or sell signal. ADX rising does not mean buy. It means a trend is strengthening, in whatever direction the +DI / −DI lines indicate. Used alone as an entry trigger, ADX is an incomplete signal by design.
The standard ADX setting is 14 periods, the value Wilder originally specified. This is the default on most charting platforms and the most widely used. A 14-period ADX on a daily chart measures trend strength over roughly the last two weeks of trading.
Shorter settings (for example 7 periods) make ADX more responsive but noisier, producing more false readings. Longer settings (for example 21 or 30) smooth the line and reduce noise but lag further behind price. For most purposes the default 14 is the right starting point, and changing it should be driven by testing on your specific timeframe rather than preference.
ADX is a lagging indicator. It confirms a trend after it has begun, not before. By the time ADX crosses above 25, a meaningful part of the move may already have happened. This is the trade-off for reliability.
ADX also struggles during sharp, brief volatility spikes, such as those around major news events, where it can read a momentary spike as a developing trend. And in very low-liquidity markets, ADX cannot distinguish between genuine momentum and thin-order-book noise. It is a probabilistic filter that improves decisions in aggregate, not a guarantee on any single reading.
ADX is one input. RegimeLab combines it with directional analysis and EMA structure to classify the full market regime, live across 8 pairs.