What Is Force Index (FI)?
Force Index combines price change and volume to measure the strength of bulls and bears behind each move.
Quick Answer
Force Index combines price change and volume to measure the strength of bulls and bears behind each move.
What Does FI Measure?
Force Index was developed by Alexander Elder. The raw value is simply the change in price multiplied by volume — positive when price rises on volume, negative when price falls on volume. A smoothed version (typically 13-period EMA) filters the raw values into a readable oscillator. Large positive Force Index readings show strong buying conviction; large negative readings show strong selling pressure. Zero-line crossovers and divergences provide trade signals. VaultCharts includes Force Index as a free subpane indicator on desktop charts.
Raw Force Index = (Close - Previous Close) × Volume; Smoothed FI = EMA of Raw Force IndexHow to Read FI
- 1Positive Force Index indicates buying pressure dominates
- 2Negative Force Index indicates selling pressure dominates
- 3Large spikes show strong conviction behind a move
- 4Divergence between Force Index and price signals weakening momentum
How to Use FI in Trading
FI Settings
| Setting | Default | Description |
|---|---|---|
| Period | 13 | EMA smoothing period for Force Index |
Common Mistakes to Avoid
Use FI in VaultCharts
VaultCharts includes Force Index with customizable settings. Combine it with our automated pattern detection and trade signals for better analysis.