Studies · Trend
Directional Movement Index (DMI / ADX)
directionalMovement · Wilder's directional movement system — +DI/−DI, DX, ADX, ADXR
Drawn in its own panelReads high, low, close
Hover the chart to read values · practice data: a seeded random walk with no overnight gaps
What it measures
Wilder's system for separating trend direction from trend strength. +DI and −DI measure how much each bar pushed beyond the previous bar's high or low, as a share of the true range. ADX smooths how lopsided those two are into one strength reading that does not care which way the trend goes.
How traders use it
- Trend or no trend: ADX above about 25 is usually read as a trending market, below about 20 as a range. Many traders only use trend-following rules when ADX says there is a trend.
- Direction: +DI above −DI says buyers are in control, the reverse sellers. A crossover of the two is the classic entry signal.
- A rising ADX means the trend is strengthening, whichever way it points; a falling ADX from a high level often marks a trend running out of steam.
Parameters
| Name | Value | Default | Allowed | What it does |
|---|---|---|---|---|
| period | 14 | ≥ 1 usual 5–50 | The smoothing length used for every line. Wilder used 14. |
Outputs
| PlusDi | +DI: upward movement as a percent of true range. |
| MinusDi | −DI: downward movement as a percent of true range. |
| Dx | DX: how one-sided the two DI lines are, 0 to 100. Noisy; ADX is its smoothed form. |
| Adx | ADX: smoothed DX, the trend-strength line most people mean by "ADX". |
| Adxr | ADXR: the average of today's ADX and the ADX period − 1 bars earlier. Wilder used it to rank markets by how trending they were. |
Drawn in one colour, one line per output, told apart by line texture. Hover the chart to read each one.
Good to know
All five lines share one panel. Most traders read just +DI, −DI and ADX together.