What do you notice about the alphas and betas calculated using the various methods? Using the alpha and beta you calculated for stock 4 along with the average excess return on the S&P index, what is your prediction of the excess return for stock 4?
Look at the investment opportunity set for stocks 1 and 2. Suppose that you produced a similar graph for portfolios of stocks 1 and 3. Where would the investment opportunity set for stocks 1 and 3 lie relative to the investment opportunity set for stocks 1 and 2? Why?
Look at your correlation table. What is the relationship between the R-squared for each stock and the correlation between that stock's returns and the S&P index returns? What do these statistics tell you about the breakdown between market risk and unique risk for each stock?
Would any combination or "weighting" of these 4 stocks result in a portfolio that is superior to the S&P 500? Explain. Do you expect this relationship in the historical data to be repeated in future periods? Explain.