First, calculate the portfolio income after adding risk-free assets:10% * 7%+90% *15% = 14.2%, and the income calculated by CAPM is also14.2%, 7%+0.9 * (/kloc-) In other words, I only earned $7.2, and invested in the fund portfolio in order to obtain the risk premium. But I found that if I put all my assets into risk-free assets, I could get107+107 =114.49 USD. So I not only didn't get the risk premium, but also lost money.