Market Facilitation Index (Bill Williams)
BW MFI measures how much price one unit of volume moved: volatility and volume combine into four colored states — Green/Fade/Fake/Squat — reading the quality of participation directly.
What it is
The Market Facilitation Index (BW MFI), created by Bill Williams: MFI = (High − Low) ÷ Volume — how much price moved per unit of volume. High = the market is "frictionless" (little volume moves price); low = "crowded" (heavy volume, no movement). Williams's genius is the four-quadrant combo: crossing the MFI's direction with volume's direction yields the Green/Fade/Fake/Squat states — a textbook framework for volume-price agreement.
Origin
BW MFI comes from Bill Williams's "Trading Chaos" (1995). Note: it shares a name with the Waner/Quong Money Flow Index (an RSI-like 80/20 volume oscillator) — they are entirely different tools, both built into MT5 (the Williams version is BWMFI). Williams used it to judge whether a price move has volume behind it — the framework's core breakout-quality tool.
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The reading and the four-color combo:
The reading is a raw per-bar value (unsmoothed) — the correct use is state-by-state color reading. Forex/CFD volume is tick volume; the four-color logic survives the tick convention but the scale differs from real-volume markets.
Worked example
A full cycle through the four states:
- Squat: heavy volume with a narrowing bar — bulls and bears changing hands fiercely; direction unresolved.
- Green: after the break, volume and range both expand — the trend confirmed and accelerating: the golden holding phase.
- Fade: price still drifts but volume and range shrink together — enthusiasm draining, the trend entering its late innings.
- Fake: range expands on insufficient volume — "a price move nobody is pushing": a reversal alarm.
The four-color frame turns the abstract "volume-price agreement" into a state machine readable bar by bar — a trend's birth (Squat → Green), maturity (Green), exhaustion (Fade) and hollowness (Fake) each have a distinct signature.
How to read it
The four-state interpretation table:
| Range | Common interpretation |
|---|---|
| Green (vol↑ range↑) | The healthiest state: real participants pushing — the safe window for trend trades |
| Squat (vol↑ range↓) | A standoff: the break is brewing — wait for direction, do not predict |
| Fade (vol↓ range↓) | Leaving the building: trend momentum spent — tighten stops, prepare to exit |
| Fake (vol↓ range↑) | A hollow move: no volume behind it — stand alert for reversal or wait for confirmation |
The states require bar-by-bar comparison of MFI and volume — MT5's BW MFI histogram colors itself, read it against a Volume sub-window. Single-bar calls are event-prone; read 3+ consecutive bars for reliable states.
Common signals & usage
Squat → Green sequence
A standoff followed by joint expansion — the classic break-and-launch sequence; direction is whatever the breakout bar says.
Consecutive fades exit
2–3 straight Fade bars in a trend — participation systematically falling: a quantified exhaustion warning; tighten stops.
Fake-move reversal alert
A price new high printing Fake — "an unsupported new high": watch for reversal; stronger with divergence signals.
Squat breakout brackets
Pre-place stop orders above and below during Squat — automatic follow-through at the moment the standoff resolves, one of Williams's original plays.
Limitations & common mistakes
- Do not confuse with the Money Flow Index: iMFI is a 0–100 RSI-like volume oscillator, BWMFI is a volume-price efficiency histogram — both live in MT5; check the prefix when reading material.
- The tick-volume caveat: forex "volume" is quote-tick count — the four-color logic holds under tick convention but the scale differs from real-volume markets.
- Event-bar interference: the giant bars of earnings/central-bank moments scramble the color sequence — wait 2–3 bars after events before calling states.
- The cost of being unsmoothed: bar-by-bar readings jitter — single-bar misclassification is common; multi-bar streaks plus trend structure are mandatory discipline.
- No direction information: the four colors describe participation quality, not direction — bull/bear always comes from price structure and trend tools.
BW MFI in MT5
BW MFI is a built-in MT5 Bill Williams indicator (a four-color sub-window histogram). The MQL5 function for programmatic use is iBWMFI:
| MQL5 function | iBWMFI() |
| Algorithm | (High − Low) ÷ Volume (per bar) |
| Volume type | VOLUME_TICK / VOLUME_REAL (selectable) |
| Buffers | 0=main buffer (MFI value); coloring is chart rendering |
| Display window | Sub-window (read against a Volume sub-window) |
The four-color state requires comparing the current bar's MFI and volume with the previous bar (the chart colors automatically; in code, compare the two series manually). applied_volume selects tick or real — forex usually only has tick volume; stocks depend on the broker's data feed.
Behavior across timeframes
15-minute
A high-frequency comparison field: color sequences switch fast intraday — read against a larger-trend direction
1-hour / 4-hour
The main swing period for volume-price states: the Squat → Green sequence is most classic here
Daily
Trend life-cycle calls (Fade/Fake) are most reliable on dailies
Weekly
Persistent weekly Green = real money continuously participating — a coarse health check for long-term trends
Indicator combinations
Common pairings for BW MFI:
- With Alligator: a mouth-open (structural expansion) + Green (volume-price both up) — double confirmation of trend health in-system. ALLIGATOR
- With Bollinger Bands: Squat (heavy volume, no range) often coincides with a Bollinger squeeze — the double signature of "the eve of a break". BOLL
- With MFI: BWMFI reads participation quality, MFI reads money-flow extremes — same-name-different-tool complementary use. MFI
FAQ
Q Are BW MFI and MFI (Money Flow Index) the same indicator?
No — the abbreviations merely collide: BWMFI is Bill Williams's Market Facilitation Index (a volume-price efficiency histogram with four color states); MFI is the Money Flow Index with 80/20 lines (an RSI-like money-flow oscillator, 0–100). Both are built into MT5 — iBWMFI and iMFI are different functions.
Q How do I see the four-color states in MT5?
The BW MFI histogram colors itself by the volume-price combo; mount a Volume sub-window and read bar by bar: the bar color plus volume direction gives the quadrant state. In code, compare the current/previous MFI and volume values manually.
Q What should I do during a Squat state?
Do not predict the direction. Squat = heavy volume with a narrowing bar — a standoff. The correct action is to wait: follow the breakout when it comes (the Squat → Green sequence), or use Williams's original play of pre-placed stop brackets for automatic follow-through.
Q Why is the Fake state dangerous?
Fake = range expanding on shrinking volume — price moves without new money behind it (often stop-loss cascades or program pushes). Such moves lack fuel and reverse easily — "an unsupported new high/low" is a common prelude to reversal.
Q How do I add BW MFI in MT5?
Menu: Insert → Indicators → Bill Williams → Market Facilitation Index, or drag it from the Navigator onto a sub-window. No period parameter (per-bar calculation); choose tick/real volume — and mount a Volume sub-window to read the colors against.
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