Money Flow Index (MFI) is the technical indicator, which indicates the rate at which money is invested into a security and then withdrawn from it. Construction and interpretation of the indicator is similar to Relative Strength Index with the only difference that volume is important to MFI.
Usage: When analyzing the money flow index one needs to take into consideration the following points: divergences between the indicator and price movement. If prices grow while MFI falls (or vice versa), there is a great probability of a price turn; Money Flow Index value, which is over 80 or under 20, signals correspondingly of a potential peak or bottom of the market.
Common known variants of this type of indicator are the On Balance Volume, Chaikin Oscillator or Chaikin Money Flow.