Sortino Ratio Calculator

Like Sharpe but only penalizes downside volatility.

How the Math Works

The Sortino Ratio is a financial metric that measures the risk-adjusted return of an investment, focusing specifically on downside risk rather than total volatility. Unlike the Sharpe Ratio which penalizes all volatility equally, the Sortino Ratio only considers returns that fall below a specified target or minimum acceptable return, typically the risk-free rate or zero. The calculation divides the excess return (actual return minus target return) by the downside deviation, which is the square root of the probability-weighted squared deviations of negative returns from the target. This approach provides a more accurate assessment of risk-adjusted performance for investors who are primarily concerned with losses rather than overall market fluctuations.

Practical Applications

To apply the Sortino Ratio in investment analysis, first determine your minimum acceptable return (MAR) - often set at the risk-free rate or zero. Calculate the average return of your investment over the period, subtract the MAR to find the excess return. Then compute the downside deviation by identifying all periods where returns fell below the MAR, squaring those deviations, multiplying by their respective probabilities, and taking the square root of the sum. A higher Sortino Ratio indicates better risk-adjusted performance with less downside risk, making it particularly useful for comparing investments with different return profiles or evaluating portfolio adjustments.

Day-to-Day Use

In your daily financial decision-making, the Sortino Ratio helps you evaluate investment opportunities beyond simple return comparisons. When reviewing your portfolio or considering new investments, this metric reveals whether higher returns come with excessive downside risk or if you're being adequately compensated for taking on risk. It's especially valuable for risk-averse investors who want to understand if an investment's volatility is primarily upward or downward in nature. By incorporating this calculation into regular portfolio reviews, you can make more informed decisions about rebalancing, identifying investments that consistently deliver positive returns with minimal downside deviation, and ultimately building a more resilient investment strategy that aligns with your risk tolerance.

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