The Sortino ratio examines the downside risk of returns. It is calculated as the portfolio return minus the minimum acceptable return (MAR) divided by a standard deviation that only uses returns below the MAR. It is similar to the target semivariance. Since Rouse’s portfolio has had consistently higher returns, she should not be penalized for any variability on the upside. The range (the difference between the highest and lowest values), standard deviation, and Sharpe ratio (which uses the standard deviation in the denominator) examine all returns, whether they correspond to positive or negative alphas. The use of these measures would result in risk measurements that are unfairly high in Rouse’s case. |
