Use ADX Rules to Trade Strong Trends

This guide explains how ADX is calculated, rules you can test, a worked example on Nifty, and how to use ADX as a filter for other strategies.

At a glance

How ADX works

J. Welles Wilder introduced ADX in 1978, in the same book as RSI and ATR. The calculation has three steps:

1. Directional movement. +DM is today's high minus yesterday's high, when that is larger than yesterday's low minus today's low. −DM is the reverse. The smaller one is set to zero.
2. Directional indicators. +DM and −DM are smoothed over 14 periods and divided by the ATR to give +DI and −DI.
3. ADX. The difference between +DI and −DI, divided by their sum, is smoothed over 14 periods.

A rising ADX means the trend is strengthening, in whichever direction the DI lines show. A falling ADX means it is weakening, even if prices are still moving.

The rules

Long trades

1. ADX(14) is above 25 and higher than 3 candles ago.
2. +DI is above −DI.
3. The price closes above the highest high of the last 10 candles.
4. Stop: 2 times ATR(14) below the entry.
5. Exit: a trailing stop of 2 times ATR, or when −DI crosses above +DI.

Short trades

The mirror image, with −DI above +DI and a break below the 10-candle low.

A worked example

On a daily chart, Nifty futures trade at 25,180. ADX is 31, up from 26 three days ago. +DI is 29 and −DI is 14. The price closes above its 10-day high of 25,150. ATR(14) is 190 points.

• Entry: 25,180
• Stop: 25,180 − 2 × 190 = 24,800
• Risk per lot of 65: 380 points, ₹24,700

The wide stop reflects the daily timeframe. Size the position so that ₹24,700 is within your risk per trade, using the position size calculator. These numbers illustrate the rules, not a result.

ADX as a filter for other strategies

ADX is often more useful as a switch than as a signal:

• When ADX is above 25, use trend-following rules, such as a moving average crossover or Supertrend.
• When ADX is below 20, use range rules, such as RSI mean reversion or Bollinger Band mean reversion.
• For option sellers, a low and falling ADX suggests a quieter market for range strategies such as an iron condor, and a rising ADX is a warning.

When the strategy works, and when it does not

Works best when:

• A clear trend is building after a breakout, such as after an event or a long range.
• The instrument trends well, such as crude oil or metal futures during strong moves.

Struggles when:

• ADX lags. By the time it rises above 25, part of the move is over.
• The market swings sharply both ways. Volatile chop can lift ADX without a lasting trend.
• ADX above 40 often marks a late stage, where reversals are common.

Automating an ADX strategy

In QuantPower's strategy builder, set ADX, +DI and −DI as indicator conditions with a breakout of the 10-candle high as the trigger. Add the ATR stop and the trailing stop, and an MTM stop loss for the day. Run it in paper trading first.

Backtesting an ADX strategy

• Test the ADX threshold (20, 25, 30) and the breakout look-back (10, 20).
• Compare the strategy with the same breakout rules without the ADX filter. A filter that removes trades should improve the average trade.
• Trend strategies win less than half the time and rely on a few large winners. Judge them by the profit factor and drawdown, not the win rate.

See backtest performance metrics.

Common mistakes

• Reading ADX as direction. A high ADX in a falling market is a strong downtrend.
• Entering when ADX is above 40. The best part of the trend may be over.
• Using tight stops. Trends pull back. A stop inside normal volatility gets hit often.

Frequently asked questions

Sources

• Wilder, J. W. (1978). New Concepts in Technical Trading Systems. Trend Research
• Murphy, J. J. (1999). Technical Analysis of the Financial Markets. New York Institute of Finance