Suppose that an investor holds a portfolio consisting of 10 shares of firm X and 10 shares of firm Y. Securities X and Y are traded at 10$ each and their prices are negatively correlated with the correlation coefficient being equal to -0.5. The annual expected retum equals x = 10% and ry = 5%, while the standard deviation of the retums equals to ox = 20% and oy = 15%, respectively. 4.1 Assuming that transaction costs are zero, how this portfolio should be rebalanced (self-financing strategy, i.e. increase/decrease the number of securities X and Y accordingly without changing the total market value of the portfolio) in order to minimize the portfolio risk? (35%) 4.2 Evaluate your findings and comment on the risk-return profile of the rebalanced portfolio (15%)