The ADX (Average Directional Index) is a technical indicator developed by J. Welles Wilder Jr. and published in his 1978 book New Concepts in Technical Trading Systems. It measures the strength of a trend — not its direction — on a scale from 0 to 100. An ADX reading below 20 indicates a weak or absent trend; above 25 signals a strengthening trend; above 40 indicates a strong trend; above 50 signals an extremely strong trend. The ADX is always displayed alongside two companion lines — the +DI (Positive Directional Indicator) and -DI (Negative Directional Indicator) — which together reveal both trend strength and direction. The complete system is formally called the Directional Movement System (DMS) or DMI (Directional Movement Index). It is one of the most widely used trend-strength indicators in technical analysis and is available as a standard tool on every major trading platform.
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The Origin of the ADX Indicator
- Welles Wilder Jr. is one of the most influential figures in the history of technical analysis. In a single book — New Concepts in Technical Trading Systems, published in 1978 — he introduced five indicators that remain in widespread professional use today: the ADX, the RSI (Relative Strength Index), the ATR (Average True Range), the Parabolic SAR, and the Commodity Selection Index. The ADX was Wilder’s solution to a specific and practical problem: distinguishing between markets that are genuinely trending and markets that are ranging or consolidating.
Wilder observed that many technical trading systems — particularly trend-following systems using moving average crossovers — performed well during trending periods but produced repeated losses during ranging markets, where price oscillates without directional conviction. His goal with the ADX was to create a filter: a quantitative measurement of trend strength that could tell a trader whether the current market environment was suitable for trend-following strategies or whether a different approach was required.
This foundational insight — that market regime identification is as important as signal generation — remains one of the most valuable and underappreciated concepts in retail trading. Understanding whether the market is trending or ranging before applying any indicator is the prerequisite to using that indicator correctly. It directly supports the rules-based approach at the heart of every effective trading plan.
The ADX is a standard indicator on every major trading platform used by brokers reviewed on CompareBroker.io, including Pepperstone, ThinkMarkets, Eightcap, Capital.com, and XM Group.
The Three Components of the ADX System
The ADX is not a standalone indicator — it is the third component of Wilder’s complete Directional Movement System. Understanding all three components is essential to reading ADX signals correctly.
Component 1: +DI (Positive Directional Indicator)
The +DI measures the strength of upward price movement. It is calculated from the Positive Directional Movement (+DM) — which captures how much of today’s price range exceeds yesterday’s range on the upside — smoothed over the ADX period (default 14) and expressed as a percentage of the Average True Range.
What it signals: When +DI is rising, upward price movement is gaining strength. When +DI is above -DI, buyers are currently dominant. The absolute level of +DI and its relationship to -DI are the directional components of the system.
Component 2: -DI (Negative Directional Indicator)
The -DI measures the strength of downward price movement — the mirror calculation of +DI using downward price range extensions.
What it signals: When -DI is rising, downward price movement is gaining strength. When -DI is above +DI, sellers are currently dominant.
Component 3: ADX (Average Directional Index)
The ADX is calculated from the smoothed average of the absolute difference between +DI and -DI, divided by their sum, multiplied by 100. It is always positive regardless of trend direction — a rising ADX means trend strength is increasing whether the trend is up or down.
What it signals: The ADX measures how strong or weak the current directional movement is, without regard to whether that movement is upward or downward. A rising ADX means a trend is developing or strengthening. A falling ADX means the trend is weakening or the market is transitioning toward a range. The ADX line does not tell you which direction the trend is moving — the +DI and -DI lines provide that information.
How the ADX Is Calculated
Understanding the calculation clarifies why the ADX behaves the way it does and prevents common misinterpretations.
Step 1: Calculate the True Range (TR)
The True Range — also used in Wilder’s ATR indicator — captures the full price range of a period, accounting for gaps from the previous close:
True Range = Maximum of:
- Current High − Current Low
- |Current High − Previous Close|
- |Current Low − Previous Close|
Step 2: Calculate Directional Movement (+DM and -DM)
+DM (Positive Directional Movement): If today’s high minus yesterday’s high is greater than yesterday’s low minus today’s low, AND greater than zero: +DM = Today’s High − Yesterday’s High. Otherwise: +DM = 0.
-DM (Negative Directional Movement): If yesterday’s low minus today’s low is greater than today’s high minus yesterday’s high, AND greater than zero: -DM = Yesterday’s Low − Today’s Low. Otherwise: -DM = 0.
If both conditions are equal or both are zero, both +DM and -DM = 0.
Step 3: Smooth TR, +DM, and -DM Over 14 Periods
Wilder uses a specific smoothing method — not a simple moving average — that weights recent data more heavily:
Smoothed TR₁₄ = Previous Smoothed TR₁₄ − (Previous Smoothed TR₁₄ ÷ 14) + Current TR
The same formula is applied to +DM and -DM.
Step 4: Calculate +DI and -DI
+DI = (Smoothed +DM₁₄ ÷ Smoothed TR₁₄) × 100 -DI = (Smoothed -DM₁₄ ÷ Smoothed TR₁₄) × 100
Step 5: Calculate the DX and ADX
DX = (|+DI − -DI| ÷ (+DI + -DI)) × 100
ADX = 14-period Wilder smoothed average of DX
The ADX therefore measures the average dominance of one directional force over the other — expressed as a percentage of their combined strength — smoothed over time.
How to Read the ADX Indicator
ADX Trend Strength Scale
The ADX reading translates directly into a market regime assessment:
ADX Value | Market Condition | Implication for Traders |
0 – 20 | Weak or absent trend | Avoid trend-following strategies; ranging conditions |
20 – 25 | Trend beginning to develop | Watch for trend-following signals; confirmation needed |
25 – 40 | Trending market | Trend-following strategies are appropriate |
40 – 50 | Strong trend | High-conviction trend-following; manage exits carefully |
50 – 75 | Very strong trend | Exceptionally strong directional move |
75 – 100 | Extremely strong trend | Rare; typically associated with major breakouts or news events |
These thresholds were Wilder’s original guidelines. The most commonly used practical thresholds in modern trading are 20 and 25 as the boundary between ranging and trending, with 40 as the indicator of a genuinely strong trend.
The Direction of the ADX Line
The direction the ADX is moving is as informative as its absolute value:
Rising ADX: Trend strength is increasing — the existing directional move is gaining momentum. This is a signal to stay in or initiate trend-following trades in the direction indicated by +DI and -DI.
Falling ADX: Trend strength is decreasing — the existing directional move is losing momentum. Even if the ADX is above 25, a falling ADX warns that the trend may be exhausting. This is not a signal to trade in the opposite direction — it is a signal to tighten exits, reduce position size, or prepare for a transition to ranging conditions.
ADX Peaking and Turning Down: When the ADX reaches a high reading (above 40 or 50) and begins turning downward, this signals potential trend exhaustion. The trend is not necessarily reversing — it may simply be decelerating into a consolidation phase. Many traders use ADX peak-and-turn as an exit signal for trend-following positions.
+DI and -DI Relationship
The relationship between +DI and -DI provides the directional context that the ADX itself lacks:
+DI above -DI: Buyers are currently dominant; the directional bias is bullish. In a trending market (ADX above 25), this confirms an uptrend.
-DI above +DI: Sellers are currently dominant; the directional bias is bearish. In a trending market (ADX above 25), this confirms a downtrend.
+DI and -DI close together: Neither buyers nor sellers are dominant; the market lacks clear directional conviction. This typically corresponds with a low ADX reading and ranging conditions.
The Four Primary ADX Trading Signals
Signal 1: ADX Trend Strength Filter
The most fundamental ADX application is as a market regime filter. Before applying any trend-following indicator — moving averages, the Ichimoku Cloud, or momentum breakout systems — check the ADX:
- If ADX is above 25 and rising: the market is trending. Trend-following signals from other indicators are reliable.
- If ADX is below 20: the market is ranging. Trend-following signals are unreliable and prone to whipsaws. Mean-reversion signals from oscillators like the Stochastic Oscillator, CCI, or Williams %R are more appropriate.
This simple application of the ADX as a regime filter dramatically improves the performance of most technical trading systems. The losses traders experience from applying trend-following strategies in ranging markets — and mean-reversion strategies in trending markets — are among the most common causes of trading losses. The ADX directly addresses this.
Signal 2: The DI Crossover
The +DI/-DI crossover was Wilder’s original primary trading signal for the Directional Movement System:
Bullish DI Cross: +DI crosses above -DI. Upward directional strength has overcome downward directional strength — a potential buy signal. Most reliable when ADX is above 20 and rising at the time of the crossover.
Bearish DI Cross: -DI crosses above +DI. Downward directional strength has overcome upward — a potential sell signal. Most reliable when ADX is above 20 and rising.
Wilder’s original rule included an important refinement called the Extreme Point Rule: when a +DI/-DI crossover occurs, the entry is triggered only when price subsequently breaks above the high of the crossover bar (for a long) or below the low of the crossover bar (for a short). This price-confirmation filter significantly reduces false crossover signals.
DI crossovers in low-ADX environments (below 20) produce frequent false signals and should generally be ignored. The DI crossover is most valuable when the ADX is already rising through the 20–25 zone, confirming that a new trend is beginning to develop.
Signal 3: ADX Rising Through 20 or 25
When the ADX has been below 20 — indicating a ranging market — and then begins rising decisively toward and through 25, this signals the potential beginning of a new trend. Combined with a +DI/-DI crossover, an ADX breakout above 25 from below is one of the earliest and most reliable signals that a significant directional move is developing.
This signal is particularly valuable for traders who use the ADX to switch between strategies: when ADX rises through 25, they transition from mean-reversion trading to trend-following. When it falls back below 20, they transition back. This adaptive approach — using the ADX to identify the appropriate strategy for current conditions — is one of the most sophisticated and practically effective applications of the indicator.
Signal 4: ADX Peak-and-Reversal (Trend Exhaustion Warning)
When the ADX has been rising strongly (above 40 or 50) and begins to turn downward from a peak, this signals potential trend exhaustion. The trend may continue — but at a slower pace — or it may transition into consolidation before a possible reversal.
This signal is most useful as an exit or position management trigger for existing trend-following positions. When a strongly rising ADX peaks and turns down, tightening stop-losses, reducing position size, or taking partial profits preserves gains accumulated during the trend’s strongest phase. It is not a reliable standalone reversal entry signal — it indicates weakening trend strength, not a confirmed change of direction.
ADX in the Context of a Complete Trading System
The ADX does not generate entry and exit prices on its own. It is a context indicator — it tells you what kind of market you are in. The complete trading system using ADX integrates it with entry and exit tools:
ADX as the filter: Determines whether trend-following or mean-reversion strategies are appropriate. +DI/-DI crossover as the direction signal: Identifies which direction the developing trend is moving. Price action, support/resistance, or other indicators as the entry trigger: Provides specific entry price confirmation. ATR or price structure as the stop-loss methodology: Defines how much risk is taken on the trade.
This four-layer structure — regime filter, direction signal, entry trigger, risk definition — is the architecture of a professional-grade trading system. Building this architecture into a written trading plan before any live trading begins is the structural foundation that separates systematic traders from emotional ones.
The fear and greed that drives most retail trading losses is most powerful when traders are operating without a defined system — reacting to every price move without the context that an indicator like the ADX provides. Knowing whether the market is trending or ranging before acting removes a significant category of emotionally-driven mistakes.
ADX Settings: Choosing the Right Period
Wilder’s original ADX used a 14-period smoothing, which remains the most widely used default. The period selection affects the indicator’s sensitivity and the frequency of signals:
Short periods (7–10): More sensitive ADX that reacts faster to changes in trend strength. Produces more signals but with more noise — particularly useful for short-term and intraday traders who need faster regime identification.
Standard period (14): Wilder’s original setting. The industry standard across all timeframes. Provides a well-validated balance between sensitivity and reliability.
Long periods (20–30): Slower, smoother ADX that identifies only the most significant trend strength changes. Fewer signals with higher average quality — appropriate for swing and position traders on daily and weekly charts.
As with any indicator, the period should be validated through backtesting on a demo account before live application. Brokers including Pepperstone, Eightcap, and Equiti provide full demo environments with complete historical data for this process.
ADX Across Different Markets
Forex
The ADX is one of the most widely used trend-strength filters in Forex trading. It is particularly valuable in a market that alternates frequently between trending sessions — the London and New York overlap — and ranging sessions — the Asian session for most major pairs. A Forex trader who applies ADX as a session filter, only taking trend-following signals during confirmed trending conditions, avoids a large category of losing trades that occur in choppy, directionless markets.
On major pairs such as EUR/USD, GBP/USD, and USD/JPY, the 14-period ADX on the 4-hour and daily charts provides reliable regime identification. Platforms at Pepperstone and ThinkMarkets provide full ADX access on MT4 and MT5 with adjustable period settings.
Cryptocurrency
In cryptocurrency markets — accessible through Binance and Bybit — the ADX frequently reaches extreme readings (above 50 or 60) during the parabolic moves that characterise crypto bull markets. These extreme readings confirm exceptional trend strength and warn traders against mean-reversion strategies during these periods. A rising ADX above 40 on a Bitcoin or Ethereum daily chart has historically preceded some of the most significant sustained price moves in those assets.
The 24/7 nature of crypto markets means the ADX can also remain at very low levels for extended periods during consolidation phases — sometimes for weeks. An ADX below 20 on a daily crypto chart during these phases is a reliable signal to wait for trend development rather than attempting to trade the range.
Stocks and CFDs
For equity traders, the ADX is a valuable tool for identifying stocks that are in strong directional moves versus those that are consolidating. A stock screener filter combining ADX above 25 with +DI above -DI identifies equities in established uptrends — a standard component of many momentum equity strategies. eToro, Capital.com, and Markets.com all provide ADX access across their equity and CFD ranges.
Commodities
Wilder developed the ADX primarily for commodity markets, and it retains a strong track record in this asset class. Oil, gold, and agricultural commodities frequently enter extended trending phases driven by supply-demand imbalances, geopolitical events, or weather disruptions — precisely the conditions where a high, rising ADX confirms the strength of a directional move and supports a trend-following approach.
Combining the ADX With Other Indicators
ADX + Moving Averages
The most classic ADX combination. Use a 50-period or 200-period moving average to identify the dominant trend direction, and the ADX to confirm that the trend is strong enough to trade. Enter long trades when price is above the MA, the MA is rising, and ADX is above 25 and rising. This three-condition filter eliminates weak-trend false signals and counter-trend entries simultaneously.
ADX + Ichimoku Cloud
Combining ADX trend-strength confirmation with the Ichimoku Cloud’s comprehensive trend framework creates a particularly robust system. Use the Ichimoku Cloud for directional bias (price above Cloud = bullish, below = bearish) and the TK Cross for entry timing — but only execute entries when the ADX is above 25 and rising, confirming that the trend has sufficient strength to sustain the move.
ADX + Momentum Oscillators
Momentum oscillators — the Stochastic Oscillator, CCI, or Williams %R — are genuinely complementary to the ADX because they measure something different. The ADX measures trend strength; oscillators measure overbought/oversold conditions and momentum extremes. When ADX is above 25 (trending market), use oscillator pullbacks to the oversold zone as trend-following entry opportunities. When ADX is below 20 (ranging market), use oscillator overbought/oversold signals as mean-reversion entries. This adaptive approach switches the interpretation of oscillator signals based on the market regime the ADX identifies.
ADX + Volume
Volume confirms whether the trend strength the ADX identifies is supported by genuine market participation. A rising ADX accompanied by expanding volume indicates institutional involvement in the move — the most reliable trend signal combination. A rising ADX with declining volume is a warning that the trend may lack conviction and be susceptible to reversal.
Common ADX Trading Mistakes
Using the ADX as a directional indicator. The ADX tells you how strong the trend is — not which direction it is going. A rising ADX does not indicate an uptrend. A falling ADX does not indicate a downtrend. Many traders misread the ADX line as a price direction indicator, which leads to incorrect trade bias. Always read the +DI and -DI lines for direction — the ADX provides only strength.
Acting on DI crossovers in low-ADX environments. +DI/-DI crossovers below ADX 20 produce constant false signals in ranging markets. Every whipsaw crossover in a ranging, choppy market looks identical to a genuine trend-beginning signal. The ADX level is the essential qualifier: DI crossovers only carry weight when ADX is above 20 and rising.
Treating any ADX reading above 25 as a buy signal. The ADX can be above 25 and falling — which means a trend was strong but is now weakening. A falling ADX above 25 is not a continuation signal; it is a warning that the trend is losing strength. The ADX must be both above the threshold AND rising to confirm active trend development.
Ignoring the ADX when it is below 20 and continuing trend-following strategies. Low ADX is the market’s clearest signal that trend-following approaches will produce losses. Continuing to apply moving average crossovers or momentum breakout strategies in a confirmed low-ADX environment, because “a trend must develop eventually,” is a discipline failure that ignores objective market feedback. The overtrading that results from forcing trend trades in ranging conditions is one of the most measurable and avoidable sources of trading losses.
Using a period that is too short on higher timeframes. A 7-period ADX on a weekly chart is measuring directional strength over only 7 weeks — potentially too short to capture the meaningful trend cycles of that timeframe. Period selection must be appropriate to both the instrument and the timeframe.
Not combining the ADX with price-based entry confirmation. The ADX identifies regime and trend strength, but it does not provide precise entry levels. Entering trades purely on DI crossovers without price-based confirmation — a breakout above a resistance level, a pullback to a moving average, a reversal candlestick pattern — increases the probability of poorly-timed entries even when the trend direction is correct.
ADX Compared to Related Indicators
Feature | ADX | Stochastic Oscillator | CCI | Ichimoku Cloud |
Primary function | Trend strength | Momentum/overbought-oversold | Momentum/mean deviation | Trend direction, S/R, momentum |
Measures direction? | No (needs +DI/-DI) | Yes (implied by level) | Yes (above/below zero) | Yes (multiple components) |
Measures strength? | Yes (primary function) | Partially | Partially | Partially (Cloud thickness) |
Bounded scale | 0 to 100 | 0 to 100 | Unbounded | N/A (multiple scales) |
Best used in | All market conditions (as a filter) | Ranging markets primarily | Ranging and trending | Trending markets |
Standalone completeness | No (needs direction tool) | Moderate | Moderate | Yes (designed as complete system) |
Wilder creation | Yes | No | No | No |
Frequently Asked Questions
What does ADX stand for? ADX stands for Average Directional Index. It is the third component of J. Welles Wilder’s complete Directional Movement System, which also includes the +DI (Positive Directional Indicator) and -DI (Negative Directional Indicator).
What is a good ADX reading for a trending market? Wilder originally defined a reading above 25 as indicating a trending market. Most modern traders use 20 as the minimum threshold for any trend activity and 25 as the threshold for a confirmed trend worth following. Readings above 40 indicate a strong trend; above 50, an exceptionally strong trend. Readings below 20 indicate ranging or trendless conditions.
Does a high ADX mean the price is going up? No. The ADX measures trend strength, not trend direction. A high ADX reading of 50 means the market is in a very strong trend — but that trend could be up or down. To determine direction, look at whether +DI is above -DI (uptrend) or -DI is above +DI (downtrend).
Can ADX be used for all asset classes? Yes. While Wilder developed the ADX primarily for commodity markets, it has been applied effectively across Forex, equities, cryptocurrencies, and indices. Its core function — measuring the strength of directional movement — is equally valid across all markets that exhibit trending and ranging behaviour.
What is the difference between ADX and RSI? The ADX measures trend strength — how strongly price is moving in one direction. The RSI measures momentum — specifically the ratio of average gains to average losses over the lookback period, used to identify overbought and oversold conditions. They measure fundamentally different things and are genuinely complementary: ADX confirms whether a trend is strong enough to follow; RSI identifies pullback entry opportunities within that trend.
Why does the ADX lag behind price moves? The ADX uses Wilder’s smoothing method — a type of exponential smoothing — applied over 14 periods to multiple calculated values. This multi-step smoothing produces a noticeable lag between actual changes in trend strength and the ADX’s reflection of those changes. This lag is a known characteristic of the indicator. It means the ADX confirms trend development rather than predicting it — making it most useful as a confirming filter rather than a leading signal.
