Aroon

The Aroon indicator, developed by Tushar Chande, measures how much time has passed since the highest high and lowest low over a given period. It consists of two lines — Aroon Up and Aroon Down — each oscillating between 0 and 100. Aroon helps identify whether an asset is trending and how strong the trend is.

Aroon Up   = ((N - bars since highest high in N periods) / N) × 100
Aroon Down = ((N - bars since lowest low in N periods) / N) × 100

• When the highest high was just 1 bar ago, Aroon Up = 100.
• When the highest high was N bars ago, Aroon Up = 0.

• Time-based — measures when the last extreme occurred, not the magnitude of price moves.
• Two lines — Aroon Up and Aroon Down provide a complete picture of trend state.
• Range 0-100 — easy to interpret at a glance.

Strong uptrend

• Aroon Up above 70 and Aroon Down below 30.

Strong downtrend

• Aroon Down above 70 and Aroon Up below 30.

Consolidation

• Both lines below 50 — no clear trend.

Crossovers

• Aroon Up crosses above Aroon Down — bullish.
• Aroon Down crosses above Aroon Up — bearish.

| Parameter | Default | Description | |-----------|---------|-------------| | Period | 25 | Lookback window for highest high / lowest low |

| Component | Description | |-----------|-------------| | AROON_UP(25) | Aroon Up line (0-100) | | AROON_DOWN(25) | Aroon Down line (0-100) |

| Condition | Meaning | |-----------|---------| | AROON_UP(25) > 70 | Strong uptrend — recent high is very recent | | AROON_DOWN(25) > 70 | Strong downtrend — recent low is very recent | | AROON_UP(25) cross_over AROON_DOWN(25) | Bullish crossover | | AROON_UP(25) > 50 | Moderate uptrend |

• Aroon is excellent at catching the start of new trends — it signals as soon as a new high/low appears.
• Combine with ADX: Aroon identifies trend direction, ADX confirms trend strength.
• Period 25 works well for daily charts; reduce to 14 for intraday.
• When both Aroon lines are near 50, the market is transitioning — wait for a clear signal.