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。
富家子弟因求官位而倾家荡产,贪污的官吏因贪财而失职守。
The challenge of climate change requires collaboration between governments, businesses, and civil society.
I don't make music for the charts. I make music for the people.
Writing is making sense of life. You work your whole life and perhaps you've made sense of one small area.