What Do the Graphs Show Me?
The below two graphs illustrate the two halves of the Sortino ratio. The numerator is identical to the numerator in the Sharpe ratio. It is the rolling excess return above and beyond the risk-free rate, as displayed in the upper graph. The lower graph illustrates how the Sortino ratio uses downside deviations, or the “bad” occurrences in a data stream as its measure of volatility risk.