You take all the risky assets ... and you analyze them first to get their-- you have to do a statistical analysis to get their expected returns, their variances, and their covariances.

你需要对所有的风险资产进行分析,首先要得到它们的-,你必须要做一个统计分析,算出它们的预期收益率，方差，和它们的协方差。

金融市场课程节选 : 耶鲁公开课

The way you would go about it, if you're a portfolio manager, is you have to come up with estimates of the inputs to these formulas-- that means the expected returns, the standard deviations, and the covariances.

你所要做的，如果你是一个资产经理，你要做的事情就是,对公式里面的一些参数进行估计-,那些参数包括预期收益，标准差，和协方差。

金融市场课程节选 : 耶鲁公开课

But, I've dropped that assumption and now I'm going on to assuming that they're taking account of their dependence on each other, taking account of their different expected returns, and taking account of their different covariances and variances; so that's what we've got.

不过我已经放弃了那个假定,我现在假定,我们需要考虑它们彼此间的相关性，它们有着不同期望收益，不同的协方差和方差;,这是我们所学到的。

金融市场课程节选 : 耶鲁公开课