ADX Indicator Explained: How to Tell a Trend From Chop

ADX answers exactly one question: is this market trending, or just chopping around? It doesn't tell you up or down. That sounds like a limitation, but it's what makes ADX useful: trend-following trades lose most of their money in sideways markets, and ADX is one of the simplest ways to stay out of them.

What ADX measures

The Average Directional Index was introduced by J. Welles Wilder in 1978, in the same book that gave us RSI and ATR. It's built from two directional lines:

• +DI measures how strongly price has been pushing to new highs,
• −DI measures how strongly it has been pushing to new lows.

When one of them clearly dominates, the market is moving in a direction. ADX takes the gap between the two (relative to their sum), smooths it over 14 periods, and scales the result from 0 to 100. A big, persistent gap means a strong trend; two lines tangled together means chop.

How to read ADX values

These are conventions traders use, not laws of physics, but they're a sensible starting point:

ADX	What it usually means
Below 20	No real trend. Ranges, chop, false breakouts.
20 to 25	A trend may be forming.
25 to 40	A strong trend.
Above 40	A very strong trend, often stretched and prone to a pause.

Two details matter as much as the level. Rising ADX means the trend is gaining strength. ADX falling from a high level means the trend is losing steam; that's a warning, not necessarily a reversal. Price can drift sideways while ADX deflates.

ADX says nothing about direction

This trips up a lot of people. A crash produces a high, rising ADX, just like a rally. So ADX is always paired with something that gives direction: the +DI/−DI lines, or simply where price sits relative to a slow moving average such as EMA 200. In our rules, the EMAs decide the direction and ADX only decides whether the trend is strong enough to trade. More on that in the EMA pullback strategy.

Best ADX settings for crypto

Period: 14. It's Wilder's original setting and the default on TradingView and most other platforms. Shorter periods react faster but flick above and below your threshold constantly; longer ones lag more.

Threshold: 20 or 25. This is the real decision. A lower threshold lets in more trades, including weaker trends; a higher one filters harder and trades less. Our live rules use ADX 14 with a minimum of 20 on the 4-hour chart. We tested a stricter 25 as well: it cut the number of trades, and the improvement we saw came mostly from one stretch of the market rather than holding up across the whole history, so we kept 20.

Here's the strength check on Ethereum (the highlighted row), updated every 4 hours:

ADX in a trading system

ADX works best as a gate, not a trigger:

1. Direction from the trend (price and EMA 50 above EMA 200 for longs).
2. Gate: ADX at or above your threshold, otherwise no trades at all.
3. Entry from something else: a pullback and a confirming candle, a breakout, a level.

Used that way, ADX doesn't tell you when to buy; it tells you when not to bother. That's often the more valuable answer. It's also a good example of confluence: trend strength is a separate thing from trend direction and momentum, so it adds real information.

Common ADX mistakes

• Treating a high ADX as a buy signal. It only says "trending". In which direction, and whether now is a good entry, are separate questions.
• Forgetting the lag. ADX is smoothed twice. By the time it confirms a trend, part of the move has happened, which is one reason to enter on pullbacks rather than at the confirmation itself.
• Reading it on very low timeframes. On a 1-minute chart, "trend strength" changes with every burst of orders. ADX is far more stable on 4h and daily charts.

The takeaway

ADX is a chop filter. Use it to switch your trend trades on and off, take direction from something else, and keep the threshold you choose. If you want to see it next to the other checks on real coins, every coin page shows the ADX reading, updated every 4 hours.