Money flow in
technical analysis is typical price multiplied by volume, a
kind of approximation to the dollar value of a day's trading.
Money flow index (MFI) is an oscillator calculated over an
N-day period, ranging from 0 to 100, showing money flow on up
days as a percentage of the total of up and down days.
Money flow is the product of typical price and the volume on
that day.
Totals of the money flow amounts over the given N days are
then formed. Positive money flow is the total for those days
where the typical price is higher than the previous day's
typical price, and negative money flow where below. (If
typical price is unchanged then that day is discarded.) A
money ratio is then formed
From which a money flow index ranging from 0 to 100 is formed.
MFI is used as an oscillator. A value of 80 is generally
considered overbought, or a value of 20 oversold. Divergences
between MFI and price action are also considered significant,
for instance if price makes a new rally high but the MFI high
is less than its previous high then that may indicate a weak
advance, likely to reverse.
It will be noted the MFI is constructed in a similar fashion
to the relative strength index. Both look at up days against
total up plus down days, but the scale, ie. what is
accumulated on those days, is volume (or dollar volume
approximation rather) for the MFI, as opposed to price change
amounts for the RSI.
It's important to be clear about what "money flow" means. It
refers to dollar volume, ie. the total value of shares traded.
Sometimes finance commentators speak of money "flowing into" a
stock, but that expression only refers to the enthusiasm of
buyers (obviously there's never any net money in or out,
because for every buyer there's a seller of the same amount).
For the purposes of the MFI, "money flow", ie. dollar volume,
on an up day is taken to represent the enthusiasm of buyers,
and on a down day to represent the enthusiasm of sellers. An
excessive proportion in one direction or the other is
interpreted as an extreme, likely to result in a price
reversal. |
