What it does
William Blau's Stochastic Momentum Index refines the classic stochastic by measuring where the close sits relative to the midpoint of the recent high-low range rather than relative to the range extremes, then double-smoothing the result with EMAs. The output oscillates between roughly +100 and -100 with a signal line, producing a smoother, less erratic oscillator than a standard %K/%D stochastic.
How to add it
Click Indicators (ƒx) in the header.
Search “Stochastic Momentum Index” and click the result.
Hover its legend row and click the gear to open settings.
How traders use it
- Readings above about +40 are commonly treated as overbought and below about -40 as oversold.
- SMI crossing above its signal line from oversold territory is a buy setup; crossing below from overbought territory is a sell setup.
- The zero line separates bullish from bearish midpoint positioning; sustained readings on one side support the prevailing trend.
- In strong trends, take only the signals aligned with the trend: buy oversold dips in uptrends, sell overbought bounces in downtrends.
- Divergences between SMI and price at extremes strengthen reversal cases.
Inputs
| Input | Type | Default | Range / Options |
|---|---|---|---|
| %K Length | number | 10 | 1–200 |
| %D Length | number | 3 | 1–200 |
| EMA Length | number | 3 | 1–200 |
Plots & styling
| Plot | Style | Default color |
|---|---|---|
| SMI | line | #2962FF |
| SMI-based EMA | line | #ff9800 |
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 |
|---|---|
| Overbought | 40 |
| Middle | 0 |
| Oversold | -40 |
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
- Like any bounded oscillator it can stay pinned at overbought or oversold levels for long stretches in strong trends, punishing premature counter-trend trades.
- The double smoothing that cleans the signal also adds lag versus the raw stochastic.