ADX (Average Directional Index)

ADX is a single line that oscillates between 0 and 100. It measures how STRONG the current trend is, not which way it's going. Readings below 20 mean the market is choppy and trendless. Readings above 25 mean a real trend is in play. Above 40 and you're in a strong, sustained move. ADX is a filter, not a signal. You don't trade ADX directly — you use it to decide whether to take other signals. A breakout signal in a market with ADX 15 is probably going to fail (no trend energy). The same breakout in a market with ADX 35 has a much higher win rate. The two companion lines (+DI and -DI) tell you direction. +DI above -DI = bullish trend. -DI above +DI = bearish trend. Crossovers between the two are early trend-change signals.