True Strength Index¶
Indicators · Momentum
Double-smoothed price-change momentum oscillator.
The True Strength Index (TSI) is a momentum oscillator that double-smooths price changes to give a clean, trend-aware read of momentum. Because it smooths twice, it filters out most of the noise that makes raw momentum jumpy, while still oscillating around a zero line that tells you whether momentum is net positive or negative. It reads a bit like a smoother, more refined MACD.
How it works¶
The block takes the one-bar change in Source, then smooths it with two successive EMAs over the Long period (25) and Short period (13); it does the same to the absolute change, and divides — normalising the result so the TSI line oscillates in a bounded range around zero. A Signal line (EMA of TSI over Signal period, 7) provides a crossover trigger, and the block exposes Bull ↑ / Bear ↓ arrows for those crosses. Above zero, momentum is bullish; below, bearish.
When to use it¶
Use TSI for momentum direction, crossovers, and divergence, much as you would MACD, but with a steadier line. The zero-line cross is the trend-state signal; the signal-line cross is the earlier (still filtered) entry; and because the line is smooth, divergence between TSI and price reads clearly. It lags — double smoothing always does — so it confirms rather than predicts.
Example¶
A momentum-confirmed pullback long: define bias with a 200-EMA, wire bars into TSI, and feed Bull ↑ into a Buy Signal only while bias is up (via an And gate). Protect with a Fixed Stop-Loss and backtest in the Tester.
Tips & gotchas¶
- Smoother than MACD, and similar in use — zero cross for trend, signal cross for timing.
- Double smoothing = real lag. It's a confirmer; don't expect it to call the exact turn.
- Divergence reads cleanly thanks to the smooth line.
- Don't shorten the periods so far that you reintroduce the noise the double smoothing removes.
Related blocks¶
Inputs¶
| Socket | Type | What to wire in |
|---|---|---|
| Source | bars / series |
Price bars or any indicator series |
Outputs¶
| Output | Type | Plots as | Description |
|---|---|---|---|
| TSI | series |
Line · sub-pane | TSI value |
| Signal | series |
Line · sub-pane | EMA-smoothed TSI |
| Bull ↑ | signal |
Signal arrows | TSI crosses above signal |
| Bear ↓ | signal |
Signal arrows | TSI crosses below signal |
Parameters¶
| Parameter | Type | Default | What it does |
|---|---|---|---|
| Long period | number · 2–200 | 25 |
|
| Short period | number · 2–100 | 13 |
|
| Signal period | number · 1–100 | 7 |
|
| Source | choice (close, open, high, low, hl2, hlc3, ohlc4) |
close |
|
| TSI color | colour | #ef5350 |
|
| Signal color | colour | #ffee58 |
Reference auto-generated from the block catalog · category Indicators.