Calculate the Gain-to-Pain Ratio of an investment portfolio or asset’s returns.

The Gain-to-Pain Ratio, popularized by Jack Schwager, divides the sum of all returns by the sum of the absolute value of all losses, summarizing the entire return history into a single measure of return earned per unit of pain endured.

The formula is as follows:

\[\text{Gain-to-Pain Ratio} = \operatorname{SUM}(\text{Returns}) / \operatorname{SUM}(| \text{Losses} |)\]

No programming experience? With the Finance Toolkit MCP server, AI assistants such as Claude and ChatGPT can calculate the Gain-to-Pain Ratio for you. Just ask in plain English.

Calculate the Gain-to-Pain Ratio in Python

The Gain-to-Pain Ratio is available in the Performance module of the open-source Finance Toolkit. Install it with:

pip install financetoolkit -U

Then call get_gain_to_pain_ratio as shown below.

from financetoolkit import Toolkit

toolkit = Toolkit(["AAPL", "TSLA"], api_key="FINANCIAL_MODELING_PREP_KEY")

toolkit.performance.get_gain_to_pain_ratio()

Which returns:

  AAPL TSLA
2021 0.2354 0.1945
2022 -0.108 -0.1871
2023 0.4034 0.3043
2024 0.2462 0.2098
2025 0.0873 0.0871
2026 0.2062 -0.0642

Parameters

get_gain_to_pain_ratio accepts the following parameters:

  • period (str, optional): The period to use for the calculation. Defaults to “quarterly” if the Toolkit is initialised with quarterly=True, otherwise “yearly”.
  • within_period (bool, optional): Whether to calculate the Gain-to-Pain Ratio within the specified period or for the entire period. Thus whether to look at the Gain-to-Pain Ratio within a specific year (if period = ‘yearly’) or look at the entirety of all years. Defaults to True.
  • 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 ratios. Defaults to False.
  • lag (int | str, 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.

The Performance module page introduces the module, and the sidebar lists all of its functions.

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