Step 12
Level: intermediate
Sortino Ratio focuses on downside volatility, so it is more suitable when investors care about downside rather than any volatility. If measured incorrectly, investors can easily reward lucky decisions and punish correct decisions but encounter an unfavorable environment.
Unlike Sharpe, Sortino only penalizes downside volatility relative to a target level. This is useful because upside volatility is usually not as unpleasant as downside volatility. However, Sortino still depends on historical data and cannot replace drawdown analysis or capital loss risk. A single return number is not enough to conclude whether a strategy is good or bad.
By knowing where the returns came from, what risks were taken, and whether the results exceeded the benchmark, investors can improve the process instead of just reacting to the final result.
Sortino Ratio focuses on downside volatility, so it is more suitable when investors care about downside rather than any volatility.
Measuring performance is not just about showing off results. The goal is to understand whether the strategy worked as expected, whether the risk was worth it, and whether the results came from skill, environment, or luck. A portfolio with high returns but too much risk may not be as good as a more stable portfolio with lower returns and suitable for your goals.
Unlike Sharpe, Sortino only penalizes downside volatility relative to a target level. This is useful because upside volatility is usually not as unpleasant as downside volatility. However, Sortino still depends on historical data and cannot replace drawdown analysis or capital loss risk.
A performance metric always has a range of uses. CAGR does not indicate drawdown. Sharpe does not see all tail risks. The wrong benchmark leads to wrong conclusions. Attribution requires sufficiently good data. So use multiple complementary metrics instead of finding a single number to represent the entire quality of an investment.
Use Sortino when you want to evaluate performance per unit of downside risk, especially with strategies that have asymmetric ups and downs.
During each review period, record the absolute return, return relative to the benchmark, drawdown, volatility and main drivers of performance. This helps you distinguish strategic issues from short-term noise, and detect early when the portfolio deviates from its original goals.
Assuming Sortino is high means there is no risk of a deep decline in the future.
A common mistake is to measure results in the way that is most favorable to the story you want to believe. Serious investors need to accept consistent metrics, appropriate benchmarks, and long enough data. Good measurement does not make the results better, but it makes the lessons clearer.
Profit exceeding target divided by downside deviation.
The fluctuation level of the results is lower than the target threshold.
The minimum acceptable return is used as a benchmark to measure downside.
There are measures of absolute returns, risk-adjusted returns, benchmark-relative returns, drawdowns, and return attribution.
Some metrics are used to compare strategies, some are used to understand investor experience, some are used to check risk.
Performance metrics depend on data quality, measurement period length, and benchmark suitability.
Application in performance measurement
The two strategies have similar overall returns and volatility, but the strategy with fewer months of steep declines usually has better Sortino.
Risk performance analysis
Assuming Sortino is high means there is no risk of a deep decline in the future. This causes investors to draw the wrong lesson and can increase risks in the next cycle.
Changing the start or end date for better results compromises the integrity of the review.
Inappropriate benchmarking makes a portfolio appear better or worse than it actually is.
Assuming Sortino is high means there is no risk of a deep decline in the future. Returns are only meaningful when accompanied by volatility, drawdown, liquidity and targets.
Exercise 1 - reflection
Get portfolio results in the most recent 12 months and analyze them from a sortino ratio perspective.
Exercise 2 - case_study
The two strategies have similar overall returns and volatility, but the strategy with fewer months of steep declines usually has better Sortino. Identify the correct conclusion, the likely wrong conclusion, and the additional data needed.
Exercise 3 - action_plan
Create a performance review sheet of 5 metrics you will track each quarter.