The money flow index (MFI) is an oscillator that ranges from 0 to 100.
In other words, the money flow index shows how much a stock was traded.
MFI is constructed in a similar fashion to the relative strength index (RSI).
Marek and Čadková (2020)[1] studied different settings of MFI parameters.
The testing was randomised in time and companies (e.g., Apple, ExxonMobil, IBM, Microsoft) and showed that MFI can beat simple buy-and-hold strategy; therefore, it can be useful for trading.