What it does
The True Strength Index (TSI) double-smooths price momentum: it takes the bar-to-bar price change, applies a long EMA (typically 25) then a short EMA (typically 13), and divides by the same double-smoothing of the absolute price change, scaled to +/-100. The division normalizes momentum so the line oscillates around zero regardless of price level. The result is a smooth momentum oscillator that tracks trend direction with fewer false wiggles than raw momentum.
How to add it
Click Indicators (ƒx) in the header.
Search “True Strength Index” and click the result.
Hover its legend row and click the gear to open settings.
How traders use it
- Zero-line crosses define trend: TSI above zero supports longs, below zero supports shorts.
- A signal-line cross (TSI versus its 7-13 period EMA) is the standard entry/exit trigger, traded in the direction of the zero-line bias.
- Commonly used overbought/oversold guides are around +25 and -25; turns from beyond those levels carry more weight than mid-range crosses.
- TSI divergence against price at new highs or lows is a reliable exhaustion warning thanks to the double smoothing.
- Combine with a longer-timeframe TSI or moving average so you fade only counter-trend extremes, not trend-side ones.
Inputs
| Input | Type | Default | Range / Options |
|---|---|---|---|
| Long | number | 25 | 1–4999 |
| Short | number | 13 | 1–4999 |
| Signal Period | number | 13 | 1–100 |
Plots & styling
| Plot | Style | Default color |
|---|---|---|
| TSI | line | #2196F3 |
| Signal | line | #E91E63 |
Every plot's color, line width and visibility can be changed on the Style tab. Precision (default 4 decimals), price-scale labels and status-line values are configurable at the bottom of the Style tab.
Reference levels
| Level | Value |
|---|---|
| 0 | 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
- The smoothing that makes it clean also makes it late; fast V-turns are largely over before TSI confirms.
- Overbought/oversold levels are not standardized and drift by instrument and timeframe, so fixed thresholds need calibration.