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。

耶鲁公开课 - 金融市场课程节选

Because of the way that we deal with taxes and mutual funds, you can get a tax bill for gains that were realized by the investment manager turning over the portfolio even though you might not have held the shares during the period when the gains were realized.

因为共同基金的收益还涉及到缴税的问题,所以你会有张税单,上面写着基金的收益部分该缴多少税,即使在实现收益的期间,你并不持有基金股份,但还是要缴税

耶鲁公开课 - 金融市场课程节选