A risk of an investment trust and a standard of a return

One of the standards that standardized a risk of an investment trust and degree of a return has the sharp ratio that Nobel prize economist Sharp developed.
I subtract an interest rate of no risk asset from a prospective return and broke this in a risk, standard deviation undertaking, and, as for the thing having a big value with plus, use will be effective.
In addition, I become gauging of a sweat shirt when I assume a denominator a beta risk.
In the case of an investment trust, an evaluation index has many the cases which a sharp ratio is used for.