Average Directional Index (ADX)
Non-directional trend-strength gauge (0–100); readings above 25 indicate a trending market, below 20 suggest a range.
DX = 100 × |+DI − −DI| / (+DI + −DI); ADX = smoothed average of DX over n periods (default 14)
The ADX is derived from the Directional Movement Index (+DI and −DI). It measures how strong a trend is, regardless of direction. A rising ADX means the trend is strengthening; falling ADX means it is weakening — even if price is still moving in the same direction.
Readings above 25 are typically considered trending; above 40 signals a strong trend. The ADX is best paired with +DI/−DI crossovers to determine direction: when +DI crosses above −DI and ADX is rising above 25, the bullish trend is gaining strength. ADX alone will not tell you which way the market is heading.