How to calculate the Money Flow Index for cryptocurrency?

The Money Flow Index (MFI) combines price and volume to gauge crypto market momentum, with readings above 70 signaling overbought conditions and below 30 indicating oversold levels.

Aug 01, 2025 at 07:43 pm

Understanding the Money Flow Index (MFI) in Cryptocurrency Trading

The Money Flow Index (MFI) is a technical oscillator that measures the flow of money into and out of a cryptocurrency over a specified period, typically 14 days. It combines price and volume data to assess buying and selling pressure. The MFI ranges from 0 to 100, with readings above 70 generally indicating overbought conditions and readings below 30 suggesting oversold conditions. Unlike the Relative Strength Index (RSI), which uses only price, MFI incorporates volume, making it a more robust indicator for cryptocurrencies, where volume can significantly influence price movements.

To apply MFI effectively, traders must first understand the components that contribute to its calculation: typical price, raw money flow, and money ratio. These elements are derived from historical candlestick data, including open, high, low, close prices, and trading volume. Each of these values plays a crucial role in determining the final MFI score.

Step-by-Step Calculation of Typical Price

The first step in computing the MFI is determining the typical price for each trading period. This value represents the average price point during a given timeframe, such as a 1-hour or daily candle. The formula for typical price is:

Typical Price = (High + Low + Close) / 3

For example, if a cryptocurrency has a high of $30,000, a low of $29,000, and a closing price of $29,500 on a given day, the typical price would be:

(30,000 + 29,000 + 29,500) / 3 = $29,500

This calculation must be repeated for each of the 14 periods used in the standard MFI computation. The typical price serves as the foundation for calculating raw money flow in the next step.

Calculating Raw Money Flow Using Volume

Once the typical price is established for each period, the next step is to calculate the raw money flow. This is done by multiplying the typical price by the trading volume for that period:

Raw Money Flow = Typical Price × Volume

Using the previous example, if the trading volume for that day was 1,000 BTC, the raw money flow would be:

29,500 × 1,000 = 29,500,000

This process is repeated for all 14 periods. The resulting values represent the total monetary value traded at the average price level during each timeframe. These raw values are then classified as either positive or negative money flow based on price movement direction.

Differentiating Positive and Negative Money Flow

To determine whether money flow is positive or negative, compare the current period’s typical price to the previous period’s typical price:

• If the current typical price is higher than the previous one, the raw money flow is classified as positive money flow.
• If the current typical price is lower, the raw money flow is considered negative money flow.
• If the typical price remains unchanged, the flow is typically assigned to neither category or treated as zero.

After categorizing each period’s flow, sum the positive money flows over the 14-period window to get Total Positive Money Flow. Do the same for negative flows to obtain Total Negative Money Flow. These aggregated values are essential for computing the money ratio.

For instance, suppose over 14 days, the sum of positive money flows is 350,000,000 and the sum of negative money flows is 150,000,000. These totals will be used in the next phase of the calculation.

Computing the Money Ratio and Final MFI Value

With the total positive and negative money flows calculated, the next step is to derive the money ratio:

Money Ratio = Total Positive Money Flow / Total Negative Money Flow

Using the example values:

350,000,000 / 150,000,000 = 2.333

Once the money ratio is obtained, the final MFI value is calculated using the following formula:

MFI = 100 – (100 / (1 + Money Ratio))

Plugging in the money ratio:

MFI = 100 – (100 / (1 + 2.333)) = 100 – (100 / 3.333) ≈ 100 – 30.00 = 70.00

Thus, the MFI value is 70, which may indicate an overbought condition depending on context and market behavior.

Implementing MFI Calculation in Python for Cryptocurrency Data

To automate MFI calculation, traders can use Python with libraries like pandas and numpy. Below is a step-by-step guide:

• Install required packages:
  pip install pandas numpy

• Import libraries:

  import pandas as pd
  import numpy as np

• Load cryptocurrency OHLCV data (Open, High, Low, Close, Volume) into a DataFrame.

• Calculate typical price:

  df['Typical_Price'] = (df['High'] + df['Low'] + df['Close']) / 3

• Compute raw money flow:

  df['Raw_Money_Flow'] = df['Typical_Price'] * df['Volume']

• Determine positive and negative flows:

  df['Price_Change'] = df['Typical_Price'].diff()
  df['Positive_Flow'] = np.where(df['Price_Change'] > 0, df['Raw_Money_Flow'], 0)
  df['Negative_Flow'] = np.where(df['Price_Change'] < 0, df['Raw_Money_Flow'], 0)

• Sum flows over 14 periods:

  df['Positive_Money_Flow'] = df['Positive_Flow'].rolling(window=14).sum()
  df['Negative_Money_Flow'] = df['Negative_Flow'].rolling(window=14).sum()

• Calculate money ratio and MFI:

  df['Money_Ratio'] = df['Positive_Money_Flow'] / df['Negative_Money_Flow']
  df['MFI'] = 100 - (100 / (1 + df['Money_Ratio']))

This script outputs a DataFrame with MFI values for each period, enabling real-time analysis.

Interpreting MFI Signals in Crypto Markets

Traders use MFI to identify potential reversals. A reading above 80 may suggest strong overbought pressure, while below 20 could signal oversold conditions. Divergences between price and MFI are also significant. For example, if Bitcoin reaches a new high but MFI fails to surpass its previous peak, this bearish divergence may indicate weakening momentum. Conversely, a rising MFI during a price dip may signal accumulating buying pressure.

Frequently Asked Questions

What is the ideal period setting for MFI in cryptocurrency trading?

The standard setting is 14 periods, commonly applied to daily or hourly charts. Shorter periods like 9 increase sensitivity and generate more signals, while longer periods like 21 reduce noise but may lag behind price action.

Can MFI be used on all cryptocurrencies?

Yes, MFI can be applied to any cryptocurrency with reliable volume data. It works best on major coins like Bitcoin and Ethereum, where volume is high and less prone to manipulation. Low-volume altcoins may produce misleading signals due to erratic volume spikes.

How does MFI differ from RSI in crypto analysis?

While both are momentum oscillators, MFI includes volume, making it more sensitive to capital inflows and outflows. RSI relies solely on price, so MFI can provide earlier warnings of trend exhaustion, especially during high-volume breakouts or sell-offs.

Is MFI effective during crypto bull or bear markets?

MFI remains functional in all market conditions. In bull markets, overbought readings may persist longer, so traders watch for divergences rather than absolute levels. In bear markets, oversold conditions can deepen, requiring confirmation from price action before assuming reversals.