ADX Thresholds: Measuring Trend Strength Without Direction
Posted: Tue Oct 27, 2026 11:27 pm
The Average Directional Index condenses the difference between positive and negative directional movement into a single line, typically on a 14-bar basis. It measures trend strength, not direction, so a high value can accompany a steady decline just as easily as a steady advance.
Common guidance treats readings under roughly 20 as weak and above roughly 25 as trending, but those figures are conventions rather than laws. Because ADX is itself a smoothed average of smoothed values, it responds slowly. A trend may be well underway before the line rises above a threshold, and the line frequently keeps climbing, or turns down only late, after the strongest portion has passed. A falling ADX from a high level means momentum is slowing, not that price has reversed.
A more careful approach is to use ADX as a regime filter rather than an entry signal, for instance enabling a breakout rule only when the line is rising and disabling a mean-reversion rule under the same condition. Thresholds deserve testing per pair and timeframe, since a level that separates regimes on one chart may separate nothing on another. Slope often adds more than level, because a fixed cut-off applied mechanically tends to confirm trends late.
Common guidance treats readings under roughly 20 as weak and above roughly 25 as trending, but those figures are conventions rather than laws. Because ADX is itself a smoothed average of smoothed values, it responds slowly. A trend may be well underway before the line rises above a threshold, and the line frequently keeps climbing, or turns down only late, after the strongest portion has passed. A falling ADX from a high level means momentum is slowing, not that price has reversed.
A more careful approach is to use ADX as a regime filter rather than an entry signal, for instance enabling a breakout rule only when the line is rising and disabling a mean-reversion rule under the same condition. Thresholds deserve testing per pair and timeframe, since a level that separates regimes on one chart may separate nothing on another. Slope often adds more than level, because a fixed cut-off applied mechanically tends to confirm trends late.