NO.PZ2015121801000083
问题如下：
A portfolio on the capital market line with returns greater than the returns on the market portfolio represents a(n):
选项：
A.
lending portfolio.
B.
borrowing portfolio.
C.
unachievable portfolio.
解释：
B is correct.
As one moves further to the right of point M on the capital market line, an increasing amount of borrowed money is being invested in the market portfolio. This means that there is negative investment in the risk-free asset, which is referred to as a leveraged position in the risky portfolio.
R = w(RF)*RF+w(RM)*RM，当组合资产的R在RF至RM之间时，weight 应该是一正一负啊，怎么会是都为正呢？请老师讲一下，不太懂
