Money Flow Index (MFI): formula and how to read it

A volume-weighted cousin of RSI, from 0 to 100. Compares the money flowing in on up days with the money flowing out on down days over 14 days, where a day's money flow is its typical price times its volume. Above 80 is traditionally called overbought and below 20 oversold.

Stock Meadow groups it under Price trend, and shows it in tables as MFI 14.

Raw money flow = typical price × volume; MFI = 100 − 100 ÷ (1 + sum of up-day flow ÷ sum of down-day flow) over 14 days

If, over 14 days, $300 million of trading came on days the typical price rose and $100 million on days it fell, MFI = 100 − 100 ÷ (1 + 3) = 75. The numbers are made up for illustration.

It runs from 0 to 100. Traders traditionally call above 80 overbought and below 20 oversold. Because it includes volume, it can confirm or contradict what RSI says. It is a filter only, because neither end is better.

It can be used as a filter and as a column, but not for scoring: it describes a company rather than making it better or worse.

• Like RSI, it can stay at an extreme in a strong trend.
• It classifies a day as up or down by the typical price alone, whatever the size of the move.
• Blank if volume data is missing; it needs 15 trading days of prices.

How Stock Meadow handles gaps. Usually blank when volume figures are missing, or there are fewer than 15 days of prices.

Treat any single metric as one clue, and read the company's financial statements before drawing a conclusion. Stock Meadow's figures are research tools based on reported data, not investment advice.

No scoring model uses it. It is a filter and a table column only.

Read about every scoring model in How scores work.

• Relative Strength Index (RSI): recent buying momentum; 50–70 is healthy.
• Chaikin Money Flow: whether days tend to close near their highs or their lows, weighted by volume.
• On-Balance Volume Trend: whether volume has flowed in on up days or out on down days.

How is MFI different from RSI?

RSI only uses price changes. MFI multiplies each day's typical price by its volume, so a move on heavy volume counts for more than the same move on thin volume.

Can I score stocks on MFI 14?

It can be used as a filter and as a column, but not for scoring: it describes a company rather than making it better or worse.

Why is MFI 14 blank for some stocks?

It is usually blank when volume figures are missing, or there are fewer than 15 days of prices. Stock Meadow leaves the figure blank rather than guessing it.