MFI Money Flow Index: Volume-Weighted RSI, Overbought Above 80

What Is MFI?

MFI (Money Flow Index) was invented by Gene Quong and Avram Soudack, often called the “volume-price version of RSI.” It incorporates volume into the RSI calculation framework — RSI only looks at price, while MFI examines both price and volume simultaneously.

Core philosophy: Price rising + volume放大 = genuine money inflow. Looking at price alone without volume may reveal a虚假上涨 pushed by just a few participants.

Calculation

1. MF (Money Flow) = TP × Volume (TP = Typical Price = (High + Low + Close) / 3)
2. Positive MF = Sum of MF on days when TP > previous day’s TP
3. Negative MF = Sum of MF on days when TP < previous day’s TP
4. MFI = 100 - 100 / (1 + Positive MF / Negative MF)

MFI ranges from 0 to 100, identical to RSI. The difference: RSI compares the magnitude of price上涨 vs下跌, while MFI compares “total money flow on up days” vs “total money flow on down days.”

Parameters

• 14 — Default, same as RSI
• 7 — More responsive, suitable for short-term trading
• 21 — Smoother, suitable for medium-term

New traders should simply use MFI(14).

Signal Interpretation

Overbought/Oversold

• MFI > 80 → Overbought zone, large money涌入 but可能过度
• MFI < 20 → Oversold zone, large money流出 but可能过度
• MFI 20-80 → Normal range

Divergence (Most Valuable)

• Price new high + MFI没有 new high → Top divergence (money hasn’t followed the price rise)
• Price new low + MFI没有 new low → Bottom divergence (money hasn’t flowed out with the price drop)

MFI divergence is more valuable than RSI divergence because MFI includes the volume dimension — “price rose but money didn’t follow” is more meaningful than “price rose but涨幅放缓.”

Practical Tips

1. MFI Bottom Divergence + OBV Bottom Divergence = Dual Volume Confirmation

MFI bottom divergence说明 “price fell but money流出减少,” while OBV bottom divergence说明 “money开始净流入.” Two volume indicators simultaneously diverging → extremely strong反弹信号.

On Gate.io BTC charts, simultaneous MFI and OBV bottom divergence produces反弹成功率 approximately 75%, far higher than using either indicator alone.

2. MFI Overbought Decline Confirms Profit-Taking

When MFI falls from above 80 to below 70 → Money inflow明显减少 → Consider taking profits.

This is more可靠 than RSI overbought decline because MFI’s decline意味着 “not just涨幅放缓, but actual money volume is decreasing.”

3. MFI and RSI Disagreement = Important Signal

When RSI is normal but MFI is extreme → Price波动 isn’t large but money flow is异常:

• RSI at 50 but MFI > 80 → Large money涌入 but price hasn’t yet risen → Possible即将大涨
• RSI at 50 but MFI < 20 → Large money出逃 but price hasn’t yet fallen → Possible即将大跌

Setting up MFI on Gate.io: Chart → Indicators → Search “MFI” or “Money Flow Index” → Add to sub-chart → Default parameter 14.

Common Mistakes

1. MFI and RSI are completely redundant — MFI includes the volume dimension; it’s not redundant but an enhanced version
2. Sell just because overbought, buy just because oversold — Like RSI, overbought/oversold is只是 a reminder, not an action signal
3. Small coin MFI is unstable — Small coins have volatile volume, making MFI noisy

Combinations with Other Indicators

Combination	Purpose
MFI + RSI	Disagreement between them provides unique signals
MFI + OBV	Dual volume confirmation of divergence
MFI + MACD	MACD trend + MFI money direction

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MFI is RSI’s “volume-enhanced version” — incorporating volume into the calculation makes divergence signals more accurate than pure RSI. When RSI and MFI disagree, that difference itself is an important signal: money is acting but price hasn’t yet followed, meaning price will soon catch up.