18. There are two ways to correctly answer this question so we will work through both. First, we can use
the CAPM. Substituting in the value we are given for each stock, we find:
It is given in the problem that the expected return of Stock Y is 11.1 percent, but according to the
CAPM the expected return of the stock should be 11.04 percent based on its level of risk. This means
the stock return is too high, given its level of risk. Stock Y plots above the SML and is undervalued.
In other words, its price must increase to reduce the expected return to 11.04 percent.
For Stock Z, we find:
The return given for Stock Z is 7.85 percent, but according to the CAPM the expected return of the
We can also answer this question using the reward-to-risk ratio. All assets must have the same
The reward-to-risk ratio for Stock Y is too high, which means the stock plots above the SML, and the
stock is undervalued. Its price must increase until its reward-to-risk ratio is equal to the market
reward-to-risk ratio. For Stock Z, we find:
The reward-to-risk ratio for Stock Z is too low, which means the stock plots below the SML, and the
19. We need to set the reward-to-risk ratios of the two assets equal to each other, which is:
We can cross multiply to get: