The market portfolio is efficient if and only if all investors hold mean-variance efficient portfolios.
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。
The historian is a prophet looking backward.
我无法了解懒惰的人,因为我们说的是不同的语言。我不了解懒惰的人,我也不想去了解。
Running a business requires social responsibility. We must not only pursue economic benefits but also pay attention to food safety and environmental protection.