What it does
The Rank Correlation Index (RCI) applies Spearman rank correlation between time and price over a lookback window: it ranks the bars by date and by price, then measures how well the two rankings agree. The result is scaled to +/-100, where +100 means price rose in perfect order through the window and -100 means it fell in perfect order. It captures the consistency of a move, not its size.
How to add it
Click Indicators (ƒx) in the header.
Search “Rank Correlation Index” and click the result.
Hover its legend row and click the gear to open settings.
How traders use it
- Readings above +80 mark a persistently rising, overbought market; below -80 a persistently falling, oversold one.
- The classic signal is the hook: RCI turning down from above +80 suggests the orderly advance is breaking, and turning up from below -80 the reverse.
- Zero-line crosses give a simple trend-direction read: above zero bullish sequencing, below zero bearish.
- Run a short and a long RCI together and act when both agree (e.g., short-period hook while long-period is still rising for pullback buys).
- Because it ranks rather than measures, it works comparably across volatile and quiet instruments without re-tuning.
Inputs
| Input | Type | Default | Range / Options |
|---|---|---|---|
| Length | number | 12 | 1–200 |
Plots & styling
| Plot | Style | Default color |
|---|---|---|
| RCI | line | #2196F3 |
Every plot's color, line width and visibility can be changed on the Style tab. Precision (default 2 decimals), price-scale labels and status-line values are configurable at the bottom of the Style tab.
Reference levels
| Level | Value |
|---|---|
| Zero Line | 0 |
Level values, colors and line styles are editable in settings.
Tips
- Use Add to favorites in the legend menu; starred studies surface at the top of the picker.
- Reference levels (where the study has them) are editable — tune them to the instrument you're trading.
- Hide the study from the legend eye instead of removing it when you only want it out of the way temporarily.
Watch out for
- In strong trends RCI saturates at +/-100 and can hook briefly without any meaningful pullback, giving premature reversal signals.
- Rank-based math ignores magnitude entirely: a window of tiny consistent gains scores the same as a window of huge ones.