VolumeLeading volume-weighted momentum oscillatorMFI

Money Flow Index MFI

A volume-weighted RSI — momentum that counts how much traded, not just how far price moved.

Quick answer: The Money Flow Index is a volume-weighted momentum oscillator that measures buying and selling pressure on a 0–100 scale, effectively an RSI that incorporates volume, flagging overbought above 80 and oversold below 20.

In simple words

MFI is often called 'volume-weighted RSI'. Like RSI it runs from 0 to 100 and flags overbought and oversold, but instead of looking at price changes alone it multiplies each move by volume, so a rise on heavy volume counts far more than a rise on thin volume. This makes MFI a stronger read of real buying and selling pressure than a price-only oscillator. Because it uses 80/20 rather than 70/30 levels, its extremes are more selective, and its divergences — where price and money flow disagree — are especially valued.

Money Flow Index — visual

How Money Flow Index looks on a chart

MFI oscillates between 0 and 100. Readings above 80 mark overbought conditions and below 20 oversold; because it is volume-weighted, its divergences from price are considered stronger warnings than a price-only oscillator's.

Professional explanation

Why it is 'volume-weighted RSI'

MFI shares RSI's structure — a 0–100 oscillator comparing up-pressure to down-pressure over a look-back — but replaces price change with 'money flow', which is the typical price multiplied by volume. Money flow on an up-day is positive, on a down-day negative, and MFI ratios positive to negative flow just as RSI ratios average gain to average loss. The effect is that a move backed by heavy volume moves MFI more than the same move on light volume, so MFI answers not just 'did price rise?' but 'did real money push it up?'.

The 80/20 levels

MFI conventionally uses 80 and 20 as overbought and oversold thresholds, tighter than RSI's 70/30. Because volume weighting makes MFI reach extremes only when both price and volume are stretched, hitting 80 or 20 is a more selective, higher-conviction event than an RSI 70 or 30. As with all such thresholds, in a strong trend MFI can remain overbought or oversold for a while, so the levels are context, not automatic triggers.

Divergence with volume behind it

MFI's most prized signal is divergence, and because volume is baked in, it carries more weight than price-only divergence. If price makes a new high but MFI makes a lower high, the new peak was made on weaker money flow — buyers are committing less capital even as price rises, a strong exhaustion warning. The bullish mirror at a low suggests selling is drying up. Traders treat MFI divergence as one of the more reliable reversal cues among volume tools.

Where it differs from RSI in practice

Because MFI incorporates volume, it can flag exhaustion that RSI misses — a rally on collapsing volume shows up as an MFI divergence while RSI may still look fine. Conversely, on days when volume data is distorted (expiry, block deals, rebalancing) MFI can be jerked around more than RSI. The two are often watched together: agreement between a volume-weighted and a price-only momentum read is a stronger signal than either alone.

Formula

Money Flow Index formula

MFI = 100 − 100 / (1 + Money Flow Ratio); Money Flow Ratio = Positive Money Flow / Negative Money Flow

Raw Money Flow = Typical Price × Volume, where Typical Price = (High + Low + Close) / 3. Flow is positive when the typical price rises versus the prior bar, negative when it falls. Default period is 14.

Typical Price — (High + Low + Close) / 3 for each bar
Raw Money Flow — Typical Price × Volume for the bar
Positive / Negative Money Flow — Sum of raw money flow on up-typical-price bars vs down-typical-price bars over N periods
Money Flow Ratio — Positive Money Flow divided by Negative Money Flow over the look-back

How it is calculated

For each bar, compute the typical price (High + Low + Close) / 3 and the raw money flow = typical price × volume.
Classify each bar's money flow as positive if its typical price rose versus the prior bar, negative if it fell.
Sum the positive money flows and the negative money flows separately over the last N periods (default 14).
Compute the Money Flow Ratio = positive money flow / negative money flow.
Compute MFI = 100 − 100 / (1 + Money Flow Ratio); read overbought above 80 and oversold below 20.

Interpretation & signals

Traders read MFI above 80 as overbought and below 20 as oversold, use the 50 line as a money-flow bias, and prize MFI divergence against price — because volume is included — as a stronger reversal warning than price-only divergence.

Buy / bullish signals

MFI crosses back up through 20 from oversold, signalling selling pressure is exhausting.
Bullish divergence: price makes a lower low but MFI makes a higher low, showing selling money is drying up.
MFI crosses above 50, confirming money flow has turned net positive.
In an uptrend, MFI pulls back toward 40–50 on light volume and turns up (continuation entry).

Sell / bearish signals

MFI crosses back down through 80 from overbought.
Bearish divergence: price makes a higher high but MFI makes a lower high, showing buying money is fading.
MFI crosses below 50, confirming money flow has turned net negative.
In a downtrend, MFI rallies toward 50–60 on light volume and rolls over.

False signals to beware

In a strong trend MFI can stay above 80 or below 20 for many bars while price keeps going.
Expiry-day, block-deal or rebalancing volume can distort money flow and produce false extremes.
Divergence can repeat several times in a powerful trend before price finally turns.

Settings, timeframe & conditions

Best settings

14 periods, 80/20 levels (Quong & Soudack default)

Avoid

Trading 80/20 crosses blindly in a strong trend

Works best in

Liquid markets with reliable volume, range-bound or gently trending

Struggles in

Thin instruments and distorted-volume days (expiry, rebalancing)

Advantages & limitations

Advantages

Incorporates volume, so it reflects real buying/selling pressure better than RSI.
Bounded 0–100 scale makes overbought/oversold easy to read.
Volume-weighted divergence is a stronger reversal warning than price-only divergence.
Selective 80/20 extremes reduce noise versus RSI's 70/30.

Limitations & disadvantages

Needs reliable volume data — unusable or misleading on thin instruments.
Distorted-volume days (expiry, block deals) can throw off the reading.
Like RSI, it stays pinned at extremes in strong trends.
Fewer signals than RSI because its extremes are more selective.

Combining Money Flow Index with other indicators

Relative Strength Index — MFI and RSI agreeing on a divergence — volume-weighted and price-only momentum both warning — is far stronger than either alone.
Volume Weighted Average Price — In intraday trading, an MFI oversold turn while price holds above VWAP aligns money-flow exhaustion with a bullish session bias.
Bollinger Bands — An MFI extreme coinciding with a tag of the outer Bollinger Band marks a high-probability, volume-confirmed mean-reversion point.

Practical examples (Nifty & Bank Nifty)

NIFTY example

Nifty rallies from 24,000 to 24,500 and prints a new high, but MFI(14) makes a lower high, reaching only 74 versus 82 at the prior peak — a bearish divergence with volume behind it. The new price high was made on weaker money flow; buyers are committing less capital. A trader treats this as a stronger warning than an RSI divergence alone and waits for price to break the prior swing low to confirm the money-flow exhaustion is showing up in price.

BANKNIFTY example

Bank Nifty sells off to 50,000 and MFI(14) drops to 16 — oversold on heavy selling volume. Rather than catching the knife, a trader waits for MFI to climb back above 20 while price holds the prior session's low, confirming selling money has dried up. Because Bank Nifty's volume is heavy and volatile, its MFI reaches 80/20 extremes faster than Nifty's, so the trader also checks that the day is not an expiry that could distort the volume input.

Common mistakes

Treating MFI overbought as an automatic sell — in a trend it signals strong money inflow, not a top.
Acting on divergence alone without waiting for price to confirm.
Using MFI on thin instruments or distorted-volume days where the volume input is unreliable.
Forgetting MFI uses 80/20, not RSI's 70/30, and mis-reading its extremes.

Professional usage

Professionals use MFI as a volume-confirmed momentum tool, valuing it above RSI when they specifically want volume in the read. They grade trend strength by whether new price highs are backed by matching MFI highs, hunt volume-weighted divergences at potential turning points, and use the 80/20 extremes as selective, higher-conviction overbought/oversold signals. It is combined with price structure and trend context, and they stay alert to expiry and rebalancing days that can distort its volume input.

Key takeaway

MFI is a volume-weighted RSI: a 0–100 oscillator that counts how much money moved price, not just how far price moved. Overbought above 80 and oversold below 20 are more selective than RSI's levels, and because volume is baked in, MFI divergence is one of the more reliable reversal warnings — read in the context of the trend and clean volume data.

Frequently asked questions

What is the Money Flow Index?

The Money Flow Index, created by Gene Quong and Avrum Soudack, is a volume-weighted momentum oscillator on a 0–100 scale. It measures buying and selling pressure by combining price and volume, and is often described as a volume-weighted version of RSI.

How is MFI different from RSI?

RSI is based on price change alone, while MFI multiplies each move by volume, so a move on heavy volume affects MFI more than the same move on light volume. This lets MFI reflect real money flow and catch exhaustion that a price-only oscillator can miss.

What are the overbought and oversold levels for MFI?

MFI conventionally uses 80 as overbought and 20 as oversold, tighter than RSI's 70/30. Because volume weighting makes MFI reach these extremes only when price and volume are both stretched, hitting 80 or 20 is a more selective signal.

What are the best MFI settings?

The standard is a 14-period MFI with 80/20 levels. Shorter periods make it more sensitive for intraday use; longer periods smooth it for positional trading. The 14-period default works well across timeframes on liquid instruments.

What is MFI divergence?

MFI divergence is when price and MFI move in opposite directions — a higher price high with a lower MFI high (bearish) or a lower price low with a higher MFI low (bullish). Because volume is included, it is considered a stronger reversal warning than price-only divergence.

Is MFI a leading or lagging indicator?

MFI is generally a leading indicator because money flow can shift before price, especially through divergence. However, it relies on past price and volume, so its signals still need confirmation.

What does MFI above 80 mean?

MFI above 80 means the market is overbought — buying pressure, weighted by volume, has been strong. It flags a potentially stretched move, but in a strong trend MFI can stay above 80, so it is not an automatic sell.

Can MFI be used for Nifty and Bank Nifty?

Yes, MFI works well on Nifty and Bank Nifty futures, which have reliable, heavy volume. Bank Nifty's higher volatility means its MFI reaches 80/20 extremes faster, and traders should be cautious on expiry days when volume can be distorted.

Why does MFI need volume data?

MFI's money-flow calculation multiplies typical price by volume, so it cannot be computed meaningfully without reliable volume. On thin or illiquid instruments the volume input is unreliable and MFI can give misleading readings.

Which is better, MFI or RSI?

Neither is universally better. MFI adds volume, so it better reflects real buying and selling pressure on liquid instruments, while RSI is simpler and unaffected by volume-data distortions. Many traders watch both, treating agreement between them as a stronger signal.

Does MFI work on intraday charts?

Yes, MFI can be applied intraday on liquid instruments, often on 5- or 15-minute charts, where its volume weighting helps confirm momentum. Intraday volume is noisier, so it is best combined with VWAP and price structure.

Voice search & related questions

Natural-language questions people ask about Money Flow Index.

What is MFI in simple words?

MFI is like RSI but it also counts volume, giving a number from 0 to 100 that shows how strong buying or selling pressure is; above 80 is overbought and below 20 is oversold.

Is MFI better than RSI?

MFI adds volume, so it can better reflect real money flow and catch exhaustion RSI misses, but it needs reliable volume data; many traders use both together for confirmation.

What does MFI above 80 mean?

MFI above 80 means the market is overbought with strong volume-backed buying, warning the move may be stretched, though in a strong trend it can stay high, so it is not an automatic sell.

Is MFI good for day trading?

Yes, MFI is useful intraday on liquid instruments because its volume weighting confirms momentum, but intraday volume is noisy, so day traders pair it with VWAP and price action.

What is MFI divergence in simple terms?

MFI divergence is when price makes a new high or low but MFI does not follow, showing the money behind the move is fading, which warns that a reversal may be coming.

Sources & references

Last reviewed 8 July 2026. Educational content only — not investment advice.