Force Index
The Force Index is one of the few momentum tools that includes volume: direction × magnitude × volume — it measures the real thrust behind every move.
What it is
The Force Index, invented by Alexander Elder, computes FI = (Close today − Close yesterday) × Volume. It fuses the three essentials of price movement — direction, magnitude and volume — into one reading: a big, fast, high-volume rise means real buying thrust; a falling market consumes thrust just the same. MT5 approximates volume with tick count for forex (no central exchange), and the raw reading is smoothed with EMA(13) for trend confirmation.
Origin
The Force Index comes from Alexander Elder's 1993 classic "Trading for a Living". Elder's premise: markets are driven by three components — price direction, extent and volume — and any indicator missing one of them is half-blind. It belongs to the same family as his Bulls/Bears Power and the Triple Screen trading system.
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Two layers — raw and smoothed:
Raw FI swings hard (volume is in the product), so the EMA-smoothed version is what traders actually use. MT5 defaults to 13 periods. Note: forex/CFD "volume" is tick count, not real traded value — it tracks participation intensity but is dimensionally different from stock-market volume.
Worked example
Why volume matters, in one example:
- Case A: price rises $1 on tripled volume — FI is strongly positive: real money endorses the move.
- Case B: price rises the same $1 on shrinking volume — FI near zero: it rose, but nobody followed — hollow thrust.
- Case C: price dips just $0.20 on huge volume — FI is deeply negative: sellers are using the still-high price to unload — a warning.
The same price change can hide completely different thrusts — that is the extra dimension the Force Index adds over pure-price momentum tools. Many "beautiful breakouts" are exposed by absent volume.
How to read it
Reading FI(13) around zero:
| Range | Common interpretation |
|---|---|
| FI > 0 and rising | Buying thrust dominant and strengthening — a healthy uptrend |
| FI > 0 but falling | Price may still rise, but thrust is fading — early exhaustion cue |
| FI < 0 and falling | Selling thrust dominant and strengthening — a healthy downtrend |
| FI < 0 but rising | Price may still fall, but selling pressure eases — early exhaustion cue |
| Zero-line cross | Thrust direction flipped; filter by the larger trend (Triple Screen usage) |
FI has no fixed overbought/oversold levels (units differ per instrument) — the correct read is relative change within the trend: new highs/lows and divergences matter far more than absolute values.
Common signals & usage
FI(13) new high confirming the trend
In an uptrend, FI(13) printing a matching new high = healthy buying thrust; a failure to make new highs = a thrust divergence — the rally's quality is deteriorating.
Pullback entry (Elder's use)
In an uptrend, FI(2) turning negative (a pulse of selling) = the timing signal for a pullback entry — the classic second screen of Elder's Triple Screen.
FI/price divergence
Price new high without a FI(13) new high — the rise lacks volume support; watch the top. Bullish divergence mirrors it.
Zero cross + trend filter
FI(13) crossing above zero while price holds above MA200 — thrust turns positive in agreement with the macro trend.
Limitations & common mistakes
- Forex tick-volume limits: MT5 forex volume is tick count, broker-dependent — different brokers can print different FI values for the same session. Direction is valid; precise values are not comparable.
- Event-volume distortion: FI explodes after NFP, earnings and central-bank decisions — such readings do not persist; do not treat them as trend signals.
- No OB/OS levels: FI is a relative-change tool — new highs/lows and divergences are the correct read; drawing fixed thresholds on FI is a beginner error.
- Smoothing period matters: 13 is for trend confirmation, 2 for entry timing — different jobs, do not mix the reads.
- Do not confuse with Momentum: Momentum is pure price change (no volume) — FI's volume dimension adds information but also depends on data quality.
Force Index in MT5
The Force Index is a built-in MT5 oscillator (histogram plus line). The MQL5 function for programmatic use is iForce:
| MQL5 function | iForce() |
| Default period | ma_period=13 |
| Default smoothing | MODE_EMA (Elder's recommended convention) |
| Volume type | VOLUME_TICK (tick count) / VOLUME_REAL |
| Display window | Sub-window (around zero) |
applied_volume chooses VOLUME_TICK (tick count) or VOLUME_REAL (real traded volume) — forex and CFD symbols usually only have tick volume; stocks/futures with real volume from the broker can use VOLUME_REAL for a reading closer to Elder's original definition.
Behavior across timeframes
15-minute
The FI(2) timing use is most active here, but demands strict trend filtering
1-hour / 4-hour
FI(13) confirmation + FI(2) pullback entries is the standard Elder swing configuration
Daily
The classic convention: FI(13) new highs and divergences are most meaningful on dailies
Weekly
Extreme weekly FI readings often mark long-term momentum turns, but samples are sparse — reference only
Indicator combinations
Common pairings (Elder's own system included):
- With MA (Elder Triple Screen): the first screen filters the trend on a higher timeframe; FI(2) pullbacks are the second screen's timing tool — systematic trend-following. MA
- With ATR: FI signals enter, ATR places stops — direction, timing and risk in one closed loop. ATR
- With RSI: FI reads thrust-with-volume, RSI reads price force — two momentum dimensions cross-checking; divergence agreement is the strongest signal. RSI
FAQ
Q Are "Force Index" and its Chinese names the same indicator?
Yes. Force Index is translated inconsistently in Chinese — 强力指数/强力指标/劲道指数/推力指数 (MT5's official Android translation) all refer to Alexander Elder's indicator with the formula (close − previous close) × volume.
Q Does FI still work for forex without real volume?
Yes, with the right expectations: MT5 uses tick count as a proxy for participation intensity — dimensionally different from real traded value but directionally correlated (active sessions tick more). Trend confirmation and divergence reads remain valid under tick volume; just never compare absolute values across brokers.
Q What is the difference between FI(2) and FI(13)?
FI(2) is extremely sensitive, catching short pulses of selling/buying pressure — Elder uses it to time pullback entries. FI(13) is smooth, used for trend confirmation and divergence analysis. One is a timing tool, the other a confirmation tool.
Q How is FI different from Momentum?
Momentum is pure price change (close vs. n periods ago) with no volume at all; FI multiplies the price change by volume. Thrust with volume and thrust without it are different animals — FI carries more information but depends on volume data quality.
Q How do I add the Force Index in MT5?
Menu: Insert → Indicators → Oscillators → Force Index, or drag it from the Navigator onto a sub-window. Defaults: 13-period EMA smoothing on tick volume — stock symbols can switch to real volume where the broker provides it.
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