roc
Rate of Change
roc(source, periods)
Parameters
| Name | Type | Description |
|---|---|---|
source |
field | Data series |
periods |
int | Lookback period |
Formula
```
ROC = ((value - value[periods]) / value[periods]) * 100
```Examples
// positive 12-period momentum
roc(close, 12) > 0;
// strong 25-period uptrend (>10% gain)
roc(close, 25) > 10;
// volume surge (>50% increase from 20 bars ago)
roc(volume, 20) > 50;
// momentum turning positive
crossover(roc(close, 12), 0);Returns
Percentage (positive = upward, negative = downward)