Indicator reference › Elder Force Index
Elder Force Index
Volume What it measures
The Elder Force Index, from Alexander Elder, combines price change and volume into a single number: the change in closing price multiplied by the volume on that bar, smoothed with an EMA. The idea is direct — a price move on heavy volume represents real conviction ("force"), while the same price move on light volume represents far less.
How readings are interpreted
A large positive Force Index means price rose on strong volume — genuine buying force. A large negative reading means price fell on strong volume — genuine selling force. A price move accompanied by a weak Force Index reading (regardless of direction) suggests the move lacks real conviction and may not hold.
Conventional levels
- Force Index sharply positive: strong buying force behind the recent move
- Force Index sharply negative: strong selling force
- Force Index near zero despite a price move: the move is happening on weak conviction — treat with caution
- Force Index divergence from price (price rises, Force Index weakens) warns of a rally losing genuine backing
Where it works, and where it does not
Works across most conditions since it directly incorporates volume alongside price rather than inferring participation indirectly. Particularly useful for distinguishing genuine breakouts from low-conviction fakeouts.
Commonly read alongside
- Volume: Naturally related since Force Index is built directly from volume
- Balance of Power: Both come from Elder's toolkit and measure a related concept — combined agreement adds confidence
- Breakout signals (Donchian, resistance breaks): A breakout confirmed by a strong Force Index reading is considerably more trustworthy than one on a weak reading
Known limitations
- A single unusually large volume bar (news, index rebalancing) can distort the reading before smoothing catches up
- Doesn't distinguish between healthy accumulation and a single large block trade
- Less standardized threshold levels than more mainstream volume indicators like OBV
In practice
- Use as a conviction filter on breakouts or trend signals from other indicators — weak Force Index on a breakout is a caution flag
- Force Index divergence from price is conventionally read as an early warning that a trend may be losing genuine backing
- Particularly useful around earnings or news events to gauge whether the reaction has real volume conviction behind it
- More commonly used as a confirmation layer than in isolation
Plot it yourself. Add this indicator to a chart, change every
parameter and watch the line move, then backtest how the rule would have
behaved on historical data — free on the S&P 500 ETF, no card.
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indicator measures and how its readings are conventionally interpreted. Nothing
here is a recommendation to buy or sell anything, and no indicator predicts
future prices. GU Analyser is an analytical tool — no money is ever traded here.