portiono Q4. (20 points) Find the beta of the four stocks using S&P 500 index ("GSPC) as the market portfolio. What can you tell from the four betas? 05. (20 points) Compute out-of-sample portfolio return of the minimum-variance portiono Q4. (20 points) Find the beta of the four stocks using S&P 500 index ("GSPC) as the market portfolio. What can you tell from the four betas? 05. (20 points) Compute out-of-sample portfolio return of the minimum-variance