Suppose that there are many stocks in the security market and that the characteristics of stocks A and B are given as follows:
Stock Expected Return Standard Deviation
A 14 % 4 %
B 19 12
Correlation = –1
Suppose that it is possible to borrow at the risk-free rate, rf . What must be the value of the risk-free rate? (Hint: Think about constructing a risk-free portfolio from stocks A and B.)