Risk is defined in the figure as the average Value-at-Risk over the six most commonly used risk methods, expressed in national currency units of a portfolio with a value of 1000. The forecasts are one trading into the future from the last observation, i.e. for 2018-08-17 Bitcoin, FTSE, SP-500, USD/EUR, JPY/EUR, GBP/EUR, CHF/EUR.
Average risk over the past month, quarter and year.
The risk according to each model, and hence captures model risk as shown here
It may be more clear with log on the y-axis, even if it seen as bad practice to have bar plots with log axis.