What Is ADX and How Do You Read It?
ADX (Average Directional Index) measures how strong a trend is, not its direction. Here is how to read the 0 to 100 scale, what the plus DI and minus DI lines mean, and how traders use it. Educational, not financial advice.
ADX (Average Directional Index) is an indicator that measures the strength of a trend on a scale of 0 to 100 — it does not tell you the direction. A low ADX means price is ranging or drifting; a rising ADX means a trend is gaining strength, whether up or down. Direction comes from two companion lines, plus DI and minus DI. This is educational, not financial advice.
Reading the ADX line (strength only)
A common rule of thumb for the ADX value:
| ADX reading | What it suggests |
|---|---|
| Below 20 | Weak or no trend (ranging) |
| 20 to 25 | Trend may be starting |
| 25 to 50 | Established trend |
| Above 50 | Very strong trend |
Remember: a high ADX in a downtrend is just as "strong" as in an uptrend — the number says nothing about up or down.
The plus DI and minus DI lines (direction)
ADX is usually plotted with two directional-indicator lines:
- Plus DI measures upward pressure.
- Minus DI measures downward pressure.
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When plus DI is above minus DI, buying pressure is dominant; when minus DI is above plus DI, selling pressure is dominant. Traders read the two together: rising ADX with plus DI on top describes a strengthening uptrend; rising ADX with minus DI on top, a strengthening downtrend.
What ADX is good and bad at
ADX is a lagging measure — it confirms strength that has already built, so it is better at describing conditions than predicting turns. It can stay low for long stretches in choppy markets and is slow to react at the very start of a move. It works best as one input among several (structure, price action), not a standalone trigger.
Common mistakes
- Treating a high ADX as "buy" — it is not directional.
- Expecting ADX to call tops and bottoms — it lags by design.
- Reading it in isolation instead of alongside market structure.
If you want objective, non-repainting trend and structure markers on your TradingView charts to pair with strength reads like ADX, VASA Trend AI is a set of educational indicators that mark trend and structure — it does not place trades or give buy or sell advice.
Takeaway
ADX answers one question well: how strong is the trend? Use the ADX line for strength, the plus DI and minus DI lines for direction, and confirm both against price structure rather than trading ADX on its own.
Educational only — not financial advice. Nothing here is a recommendation to buy or sell.
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Educational content only — not financial advice. Trading involves substantial risk of loss and is not suitable for everyone.