The ex-post real rate of return is a backward-looking measure calculated after the fact, using historical data. It reflects the actual nominal rate of return adjusted for the actual rate of inflation over the same period. The formula is:

Ex-postrealreturn=NominalreturnInflationratetext{Ex-post real return} = text{Nominal return} - text{Inflation rate}Ex-postrealreturn=NominalreturnInflationrate

This measure helps assess the purchasing power of returns after accounting for inflation.

Other options are incorrect:

A and C describe ex-ante measures (forward-looking expectations).

B calculates the nominal excess return above the risk-free rate, not the real return.