Momentum indicators
Money Flow Index
Volume-weighted momentum oscillator based on positive and negative money flow.
- Engine
- TA-Lib
- Function
MFI- Input series
- high, low, close, volume
- Outputs
- 1
How it works
MFI multiplies typical price by volume, classifies each bar's flow as positive or negative from the typical-price change, and normalizes the rolling flow ratio to a 0-to-100 oscillator.
Use case
Use MFI as a price-and-volume momentum feature for relative buying or selling pressure, divergences, and extreme conditions.
Parameters
| Parameter | Type | Default | Bounds or options | Description |
|---|---|---|---|---|
| Time Period | integer | 14 | 2…100000 | Number of bars used to accumulate positive and negative money flow. |
Outputs
| Output | Type | Description |
|---|---|---|
| MFI | number | Money Flow Index value for the bar, normally ranging from 0 to 100. |
Reading the result
MFI combines bar prices and volume to describe the balance of positive and negative money flow over the selected history. It can add context that a price-only oscillator does not contain.
Its usefulness depends on the meaning and consistency of the provider’s volume field. Crypto volume can differ by venue, symbol representation, aggregation, and provider methodology.
Common mistakes
- Assuming volume is directly comparable across providers or venues.
- Treating a bounded extreme as an automatic reversal.
- Using MFI without checking omitted or zero-volume periods.
- Interpreting provider volume as capital flow in a broader market.
DataCat workflow notes
Record provider provenance whenever MFI enters a feature set. If you compare datasets, first validate that their volume columns describe compatible units and market scope.