Calculate the Money Flow Index (MFI) for a given price series.

The Money Flow Index is a momentum indicator that measures the strength and direction of money flowing in and out of a security by considering both price and volume.

The formula is as follows:

\[\text{MFI} = 100 - (100 / (1 + (\text{positive\_money\_flow} / \text{negative\_money\_flow})))\]

Also known as: MFI, volume-weighted RSI.

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Calculate the Money Flow Index in Python

The Money Flow Index is available in the Technicals module of the open-source Finance Toolkit. Install it with:

pip install financetoolkit -U

Then call get_money_flow_index as shown below.

from financetoolkit import Toolkit

toolkit = Toolkit(tickers=["AAPL", "MSFT"])

toolkit.technicals.get_money_flow_index()

Which returns:

Date AAPL MSFT Benchmark
2026-06-18 34.2012 17.0425 45.4099
2026-06-22 40.4098 6.0393 40.4024
2026-06-23 33.9909 13.2653 35.5328
2026-06-24 34.0195 13.2877 35.3632
2026-06-25 31.7751 12.5721 29.9219
2026-06-26 50.9525 34.8784 30.7073
2026-06-29 58.3251 40.8726 36.5958
2026-06-30 65.173 46.3834 44.023
2026-07-01 70.4341 51.8574 49.9149
2026-07-02 71.4645 57.9088 41.6417

Parameters

get_money_flow_index accepts the following parameters:

  • period (str, optional): The time period to consider for historical data. Can be “daily”, “weekly”, “quarterly”, or “yearly”. Defaults to “daily”.
  • close_column (str, optional): The name of the column containing the close prices. Defaults to “Adj Close”.
  • window (int, optional): The number of periods for calculating the MFI. Defaults to 14.
  • rounding (int | None, optional): The number of decimals to round the results to. Defaults to 4.
  • growth (bool, optional): Whether to calculate the growth of the indicator values. Defaults to False.
  • lag (int | list[int], optional): The lag to use for the growth calculation.
  • standardize (bool, optional): Whether to standardize (Z-Score) the result. When combined with growth=True, standardizes the growth values instead of the raw values. Defaults to False. Defaults to 1.
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The Technicals module page introduces the module, and the sidebar lists all of its functions.

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