当且仅当所有投资者都持有均值-方差有效的投资组合时,市场组合才是有效的。
Denying or deflecting a compliment is rude. Accept it with thanks, even if you believe it is not deserved.
The only man who behaves sensibly is my tailor; he takes my measure anew every time he sees me, while all the rest go on with their old measurements.