Trend strengthLagging trend-strength and direction indicator

Aroon Indicator

Two lines that measure how recently price made its highest high and lowest low.

Quick answer: The Aroon indicator uses two lines — Aroon Up and Aroon Down — to measure how many periods have passed since the highest high and lowest low, revealing whether a trend is present, its direction and its strength on a 0–100 scale.

In simple words

Aroon (Sanskrit for 'dawn's early light') is built on a simple idea: in a strong uptrend, new highs happen recently and often; in a strong downtrend, new lows do. Aroon Up measures how recently the highest high occurred over the look-back, and Aroon Down how recently the lowest low did, each on a 0–100 scale. When Aroon Up is high (near 100) and Aroon Down is low, the market is trending up; the reverse means down. When both are low and tangled, there is no trend. It is a time-based way to spot the birth and death of trends.

Aroon Indicator — visual

How Aroon Indicator looks on a chart

Aroon Up (measuring time since the highest high) and Aroon Down (time since the lowest low) each range 0–100. Aroon Up near 100 with Aroon Down low signals an uptrend; the reverse signals a downtrend.

Professional explanation

A time-based, not price-based, measure

Most indicators measure how much price has moved; Aroon measures how recently it made an extreme. Aroon Up = 100 × (N − periods since highest high) / N. If the highest high of the last 25 bars was today, Aroon Up is 100; if it was 25 bars ago, Aroon Up is 0. Aroon Down does the same for the lowest low. This time-since-extreme logic makes Aroon good at detecting when a trend is starting or ending, because fresh extremes cluster at the start of trends and stop appearing when trends die.

Reading the two lines

The relationship between the lines tells the story. Aroon Up above 70 with Aroon Down below 30 signals a healthy uptrend — new highs are recent, new lows are stale. The mirror signals a downtrend. When both lines are below 50 and moving together, the market is consolidating with no new extremes, i.e. rangebound. Crossovers of the two lines flag potential trend changes: Aroon Up crossing above Aroon Down is bullish.

Strength from the levels

The individual levels grade strength. An Aroon Up pinned at 100 means the market is making a new high nearly every bar — a very strong uptrend. As the uptrend tires and new highs become less frequent, Aroon Up steps down from 100 toward 50, warning of weakening before price actually reverses. So the height of the dominant line is a strength gauge, much as ADX is, but expressed through recency of extremes.

Aroon vs ADX and DMI

Aroon overlaps with Wilder's Directional Movement system — both grade trend and, in Aroon's case, direction too. But Aroon's logic is different: it is purely about the timing of highs and lows, not the size of directional moves. This makes it quicker to flag a brand-new trend (the first fresh high snaps Aroon Up toward 100) but also more prone to reacting to a single extreme bar. Many traders use it alongside a momentum tool for confirmation.

Formula

Aroon Indicator formula

Aroon Up = 100 × (N − periods since highest high) / N; Aroon Down = 100 × (N − periods since lowest low) / N

N is the look-back period, default 25. Each line ranges from 0 (the extreme was N bars ago) to 100 (the extreme is the current bar).

Aroon Up — How recently the highest high occurred over N periods, scaled 0–100
Aroon Down — How recently the lowest low occurred over N periods, scaled 0–100
Periods since highest high — Number of bars back to the highest high within the look-back window
N — Look-back period, default 25 bars

How it is calculated

Choose a look-back N (default 25).
Find how many bars ago the highest high in the last N bars occurred.
Compute Aroon Up = 100 × (N − that number) / N; if the highest high is the current bar, Aroon Up is 100.
Find how many bars ago the lowest low occurred and compute Aroon Down the same way.
Read Aroon Up above 70 with Aroon Down below 30 as an uptrend, the reverse as a downtrend, and both low as a range; watch for crossovers.

Interpretation & signals

Traders read Aroon three ways: the dominant line's level (Aroon Up high = uptrend, Aroon Down high = downtrend), crossovers of the two lines (trend changes), and both lines low together (no trend, consolidation).

Buy / bullish signals

Aroon Up crosses above Aroon Down, signalling a shift toward an uptrend.
Aroon Up rises above 70 while Aroon Down falls below 30, confirming a strong uptrend.
Aroon Up reaches 100 and stays there, showing the market makes new highs almost every bar.
After a consolidation with both lines low, Aroon Up breaks upward first (new-trend birth).

Sell / bearish signals

Aroon Down crosses above Aroon Up, signalling a shift toward a downtrend.
Aroon Down rises above 70 while Aroon Up falls below 30, confirming a strong downtrend.
Aroon Up steps down from 100 toward 50 as new highs become infrequent (uptrend weakening).
After a consolidation, Aroon Down breaks upward first (new downtrend beginning).

False signals to beware

A single extreme bar can snap a line to 100, giving a premature trend signal.
When both lines hover near 50, crossovers whipsaw with no real trend behind them.
In a fast reversal Aroon can lag because it depends on the look-back window of extremes.

Settings, timeframe & conditions

Best settings

25 periods (Chande default), 70/30 as trend thresholds

Avoid

Acting on crossovers when both lines are low and the market is ranging

Works best in

Markets transitioning from range to trend and back

Struggles in

Choppy markets that make scattered, isolated extremes

Advantages & limitations

Advantages

Detects the birth and death of trends earlier than size-based tools, via fresh extremes.
Gives both direction and strength from two easy-to-read 0–100 lines.
Clearly identifies consolidation when both lines are low.
The dominant line's level is an intuitive trend-strength gauge.

Limitations & disadvantages

A single new high or low can jerk a line to 100, producing premature signals.
Crossovers whipsaw when neither line is dominant.
Time-based logic ignores the size of moves entirely.
Less widely known and supported than ADX or moving averages.

Combining Aroon Indicator with other indicators

Average Directional Index — Aroon flags the direction and timing of a new trend while ADX confirms it has enough strength to trade, filtering Aroon's premature single-extreme signals.
Relative Strength Index — RSI adds momentum and overbought/oversold context to Aroon's timing-of-extremes read, confirming trend births.
Moving Average — A moving-average trend filter validates Aroon crossovers, keeping you aligned with the larger trend.

Practical examples (Nifty & Bank Nifty)

NIFTY example

Nifty has been consolidating and both Aroon lines sit below 50 — no trend. Then Nifty prints a fresh 25-day high and Aroon Up snaps to 100 while Aroon Down slides toward 20. That combination — Aroon Up at 100, Aroon Down low, after a period of both lines being tangled — signals a new uptrend is being born, days before a lagging moving average would confirm it. As long as Aroon Up holds above 70, the uptrend is intact.

BANKNIFTY example

Bank Nifty has been rallying with Aroon Up pinned near 100, but over two weeks new highs come less often and Aroon Up steps down from 100 to 60 while Aroon Down begins climbing from 10 toward 40. That fading of Aroon Up warns the uptrend is losing vigour before price rolls over. When Aroon Down finally crosses above Aroon Up, it confirms sellers have taken timing control — Bank Nifty's volatility means these transitions can be sharp.

Common mistakes

Acting on a line hitting 100 from a single extreme bar without confirmation.
Trading crossovers when both lines are low and there is no trend.
Reading Aroon like a momentum oscillator — it measures timing of extremes, not price change.
Using too short a look-back, which makes the lines jump erratically.

Professional usage

Professionals use Aroon mainly as an early trend-detection and regime tool. Because a fresh extreme snaps the dominant line toward 100, Aroon can flag a new trend at its birth — but that same sensitivity produces false starts, so it is paired with a strength filter like ADX or a momentum indicator for confirmation. The most valued read is the step-down of a dominant line from 100, which warns a mature trend is losing its supply of new extremes before price confirms the turn.

Key takeaway

Aroon measures how recently price made its highest high and lowest low: Aroon Up near 100 with Aroon Down low is a strong uptrend, the reverse a downtrend, and both low a range. Its strength is spotting trends at birth and death through the timing of extremes — but a single spike can mislead, so confirm its signals with strength or momentum.

Frequently asked questions

What is the Aroon indicator?

The Aroon indicator, created by Tushar Chande in 1995, uses two lines — Aroon Up and Aroon Down — to measure how many periods have passed since the highest high and lowest low. It reveals trend presence, direction and strength on a 0–100 scale.

What do Aroon Up and Aroon Down mean?

Aroon Up measures how recently the highest high occurred and Aroon Down how recently the lowest low occurred, each scaled 0–100. Aroon Up near 100 with Aroon Down low signals an uptrend; the reverse signals a downtrend.

What are the best Aroon settings?

The default is 25 periods, as Chande designed it, with 70 and 30 as the common trend thresholds. Shorter look-backs make Aroon more reactive and prone to jumping; longer ones smooth it for positional use.

What is an Aroon crossover?

An Aroon crossover is when Aroon Up and Aroon Down cross. Aroon Up crossing above Aroon Down is a bullish signal that an uptrend may be starting; Aroon Down crossing above Aroon Up is bearish. Crossovers are most reliable when the lines then separate strongly.

Does Aroon show trend strength or direction?

Both. The dominant line shows direction — Aroon Up on top means up, Aroon Down on top means down — and its level shows strength: a line pinned near 100 indicates a very strong trend making frequent new extremes.

How is Aroon different from ADX?

Both grade trends, but Aroon measures the timing of new highs and lows while ADX measures the size of directional movement. Aroon also gives direction directly through its two lines, whereas ADX needs the separate DI lines for direction.

What does it mean when both Aroon lines are low?

When both Aroon Up and Aroon Down are below 50 and moving together, the market is not making significant new highs or lows — it is consolidating or ranging with no clear trend. Trend signals in this state are unreliable.

Is Aroon a leading or lagging indicator?

Aroon is technically lagging, since it depends on past extremes, but its time-based logic lets it flag brand-new trends quickly when a fresh extreme snaps the dominant line toward 100, giving it a somewhat leading feel at trend births.

Why does Aroon Up hit 100?

Aroon Up reaches 100 when the highest high of the look-back window is the current bar — the market just made a new high. If it makes new highs repeatedly, Aroon Up stays pinned at 100, signalling a strong, persistent uptrend.

Can Aroon be used for Nifty and Bank Nifty?

Yes. Aroon works on any liquid instrument. On Nifty and Bank Nifty it is useful for spotting when a range is giving way to a new trend, though Bank Nifty's volatility can make the lines move sharply, so confirmation is advisable.

What is the difference between Aroon and the Aroon Oscillator?

The Aroon indicator plots the two separate lines, while the Aroon Oscillator subtracts Aroon Down from Aroon Up into a single line oscillating between −100 and +100. Above zero is bullish, below zero bearish; it is a condensed version of the same information.

Does Aroon give false signals?

Yes. A single extreme bar can snap a line to 100 and trigger a premature trend signal, and crossovers whipsaw when both lines are near 50. Aroon is best confirmed with a strength filter like ADX or a momentum indicator.

Voice search & related questions

Natural-language questions people ask about Aroon Indicator.

What is the Aroon indicator in simple words?

Aroon has two lines that measure how recently the market made a new high and a new low. When the up line is high and the down line is low, the trend is up; when the opposite is true, the trend is down.

Is an Aroon crossover a buy signal?

Aroon Up crossing above Aroon Down can be a buy signal that an uptrend is starting, but it is more reliable when the lines then separate strongly and both were not stuck near the middle.

What does Aroon Up at 100 mean?

It means the market just made a new high for the look-back period. If it stays at 100, the market keeps making new highs, which signals a strong uptrend.

Is Aroon good for spotting new trends?

Yes, that is its main strength. Because a fresh high or low snaps the dominant line toward 100, Aroon can flag a new trend early, though a single spike can mislead, so confirmation helps.

What does it mean when both Aroon lines are low?

It means the market is not making fresh highs or lows — it is stuck in a range or consolidating. In that state Aroon's crossover signals are unreliable.

Sources & references

Last reviewed 8 July 2026. Educational content only — not investment advice.