Average Directional Index (ADX)

ADX measures how *strong* a trend is — but not which way it points. A high ADX means a market is trending powerfully, up or down; a low ADX means it's drifting or ranging.

In 30 Seconds

• ADX measures trend strength, not direction — high ADX = strong trend (either way), low ADX = weak/ranging.
• It's directionless. A powerful downtrend and a powerful uptrend can both show high ADX.
• Low ADX doesn't mean "about to reverse" — it means the market is currently trendless.
• MPM uses ADX to define "strong trend" objectively — a disclosed threshold, reported as context.

Definition

ADX was developed by J. Welles Wilder (the same author as ATR and RSI) as part of the Directional Movement system. It's derived from comparing the range of directional movement over a period, then smoothing it. The result is a single line, usually scaled 0–100, where:

• Low values — weak trend; the market is ranging or drifting.
• High values — strong trend; the move is powerful and committed.
• Rising ADX — the trend (whichever way) is strengthening.
• Falling ADX — the trend is weakening, regardless of direction.

The essential, easily-missed point: ADX is directionless. It's built to measure *how much* a market is trending, not *which way*. A market crashing hard and a market rocketing up can post identical ADX readings. Direction comes from other tools (or from the price itself); ADX only measures conviction.

"ADX measures how strong a trend is — never which direction it goes."

Why It Matters

Knowing whether a market is trending or ranging changes how you read everything else. A level that reliably holds in a ranging market may get sliced through in a strong trend; a momentum reading that means "overextended" in a range may mean "healthy trend" when ADX is high. ADX gives an objective handle on that "trending vs. ranging" question.

Its honest value is as a *regime descriptor*: it helps distinguish "the market is going somewhere with conviction" from "the market is chopping around." That context is genuinely useful — but only if you remember ADX adds no directional information. The mistake is asking ADX "which way?" It doesn't answer that. It answers "how strongly?"

How It Works (a simple example)

Imagine two markets. One grinds sideways in a tight range for days — lots of small up and down moves, no net progress. Its ADX will be low, correctly telling you there's no strong trend. The other market falls steadily, day after day, in a committed downtrend. Its ADX will be high — correctly telling you the trend is strong.

Now notice: the *high* ADX belonged to the *falling* market. High ADX didn't mean "up" — it meant "strong," and the strength happened to be downward. If you'd read high ADX as bullish, you'd have been badly wrong. That's the whole lesson: ADX told you the trend was powerful; the *chart* told you it was down.

How MPM Uses ADX

MPM uses ADX to give the phrase "strong trend" an objective, disclosed meaning:

• "Strong trend" is a defined threshold. Rather than a subjective judgment of whether a market is "really trending," HIE resolves a strong-trend condition to a disclosed ADX threshold and shows it in "What ran."
• It's a condition, not a signal. A strong-trend condition is reported beside the base rate — what history did under it — never as a directional instruction.

HIE uses a 14-period ADX (Wilder-smoothed). "Strong trend" resolves to ADX above 25, shown on the standard 0–100 ADX scale in the "What ran" line — for example:

'strong trend' → trend strength (ADX) above 25

The same 25 threshold defines the "trending" versus "ranging" regime language (ADX at or above 25 = trending; below 25 = ranging), so "strong trend" always means the same measured thing.

Interpretation

• Low ADX — weak or absent trend; market is ranging or drifting. NOT a reversal signal — just an absence of strength.
• High ADX — strong trend in force; the move is committed. Direction must come from price, not ADX.
• Rising ADX — the current trend is strengthening.
• Falling ADX — the current trend is losing steam (not necessarily reversing — could be pausing).

The honest reading: ADX is a strength meter. Pair it with the direction of price to know "strong up" versus "strong down" — ADX alone gives you only the "strong."

Common Mistakes

"High ADX is bullish."

The most common ADX error. High ADX means a strong trend in *either* direction. A powerful downtrend shows high ADX too.

"Low ADX means a reversal is coming."

Low ADX means no strong trend right now — ranging or drifting. It's an absence of trend strength, not a prediction of a turn.

"ADX tells me when to enter."

ADX describes regime (trending vs. ranging), not timing or direction. It's context for other decisions, not an entry signal.

What It Is Not

• Not a direction indicator. High ADX is directionless — strength only.
• Not a reversal signal. Low ADX means no trend, not an impending turn.
• Not an entry tool. It describes trend strength, nothing about timing.

Limitations

ADX is a lagging, smoothed indicator — it confirms trend strength after it's underway rather than anticipating it, and it can be slow to reflect a shift from trending to ranging or vice versa. Its readings depend on the period and threshold chosen, and common defaults are conventions, not laws. Most importantly, ADX measures only one dimension — strength — and adds nothing about direction, so it must always be combined with a directional read to be actionable.

How This Fits Into MPM

ADX underpins how MPM can talk about "strong trends" or "trending regimes" objectively rather than by feel — a disclosed number behind an otherwise subjective label.