Aroon¶
Indicators · Momentum
0-100 oscillator: bars-since-high vs bars-since-low.
Aroon (Sanskrit for "dawn's early light") spots the birth of trends. It does this by measuring something refreshingly simple: how recently price made its highest high and lowest low within a look-back window. Aroon Up is high when the most recent bar is at or near the period's high; Aroon Down is high when it's near the low. When one line is up near 100 and the other is crushed near 0, a fresh trend is underway — and the moment they cross is your early heads-up.
How it works¶
Over the Period (default 14) the block finds how many bars ago the highest high occurred and converts it to a 0–100 scale: if the high is the current bar, Aroon Up = 100; if it was the oldest bar in the window, it's near 0. Aroon Down does the same for the lowest low. Both plot in a sub-pane on a 0–100 scale. A reading near 100 means "we just made a new extreme"; a low reading means "it's been a while." The lines crossing, and either line pinning near 100 or 0, are the signals.
When to use it¶
Use Aroon to detect new trends early and gauge trend strength. The classic signals: Aroon Up crossing above Aroon Down flags an emerging uptrend (and vice-versa); Aroon Up holding above ~70 while Aroon Down sits below ~30 confirms a strong, healthy uptrend; both lines low and tangled in the middle means a range with no trend — stand aside. Because it's based on the timing of extremes rather than their size, it can flag a trend change a touch earlier than magnitude-based tools, but it also fires false starts in choppy conditions.
Example¶
Catch a new trend: wire bars into Aroon and take the Aroon-Up-crosses-Aroon-Down event via a Crosses Above into a Buy Signal, ideally requiring Aroon Up to then hold above 70 for confirmation. Filter ranges by skipping signals when both lines are mid-scale. Backtest in the Tester.
Tips & gotchas¶
- Based on timing of extremes, not their size — that's what lets it flag turns early.
- Both lines low + tangled = range. No trend; don't force a trade.
- A line pinned near 100 confirms a strong one-directional trend.
- False starts in chop — confirm the cross with a hold above 70, or gate with ADX / DMI.
Related blocks¶
Inputs¶
| Socket | Type | What to wire in |
|---|---|---|
| Bars | bars |
OHLC bars (high/low required) |
Outputs¶
| Output | Type | Plots as | Description |
|---|---|---|---|
| Aroon Up | series |
Line · sub-pane | Strength of upward trend (100 = high is current bar) |
| Aroon Down | series |
Line · sub-pane | Strength of downward trend (100 = low is current bar) |
Parameters¶
| Parameter | Type | Default | What it does |
|---|---|---|---|
| Period | number · 2–500 | 14 |
Lookback window length |
| Aroon Up color | colour | #26a69a |
|
| Aroon Down color | colour | #ef5350 |
Reference auto-generated from the block catalog · category Indicators.