Carhart Four-Factor Model
Calculate Carhart Four Factor model scores for a set of financial assets.
The Carhart Four Factor model extends the Fama and French Three Factor model with a momentum factor, based on the observation that stocks with high prior returns (winners) tend to keep outperforming stocks with low prior returns (losers) over the medium term:
- Market Risk Premium (Mkt-RF): The excess return of the market over the risk-free rate.
- Size Premium (SMB): The historical excess return of small-cap stocks over large-cap stocks.
- Value Premium (HML): The historical excess return of value stocks over growth stocks.
- Momentum (MOM): The historical excess return of prior winner stocks over prior loser stocks.
The model performs a Multi Linear Regression on all four factors and defines the regression parameters for each asset over time based on its exposure to these factors:
- Excess Return = Intercept + Beta1 * Mkt-RF + Beta2 * SMB + Beta3 * HML + Beta4 * MOM + Residuals
For more information about the method, see the following paper:
- Carhart, M.M. (1997). “On Persistence in Mutual Fund Performance.” The Journal of Finance, 52(1), 57-82.
Also known as: Carhart model, four-factor model, momentum-augmented Fama-French model.
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Calculate the Carhart Four-Factor Model in Python
The Carhart Four-Factor Model is available in the Performance module of the open-source Finance Toolkit. Install it with:
pip install financetoolkit -U
Then call get_carhart_four_factor_model as shown below.
from financetoolkit import Toolkit
toolkit = Toolkit(["AMZN", "TSLA"], api_key="FINANCIAL_MODELING_PREP_KEY")
toolkit.performance.get_carhart_four_factor_model(period="quarterly")["AMZN"]
Parameters
get_carhart_four_factor_model accepts the following parameters:
- period (str, optional): The period for the calculation (e.g., “weekly”, “monthly”, “quarterly”, “yearly”). Defaults to “quarterly” if the Toolkit is initialised with quarterly=True, otherwise “yearly”.
- rounding (int, optional): The number of decimals to round the results to. Defaults to 4.
- growth (bool, optional): Whether to calculate the growth of the ratio values. Defaults to False.
- lag (int or list of int, optional): The lag to use for the growth calculation. Defaults to 1.
- 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.
- show_columns (list of str, optional): Restrict the result to these top level columns. Defaults to None, which returns every column.
Related Performance Metrics
The Performance module page introduces the module, and the sidebar lists all of its functions.