An investor invested 10 million in long term companies bonds. The estimated annual return is 9% and the standard deviation is 10%. His financial advisor recommended to invest in a fund linked with an index which follows closely S&P 500 with estimated annual return 14% and standard deviation 16%. Maybe it's better to invest equal amounts at the portfolio of the companies' bonds and the fund which is linked to the index? The correlation between the portfolio of the companies' bonds and the fund is +0.1