.. The portfolio expected return-- x3 we have to choose three things now: x1, x2, and x3.

要计算投资组合的预期收益-,我们必须确定三个值x1，x2和。

耶鲁公开课 - 金融市场课程节选

is two, 10% it means that if the market goes up 10% in value, the stock tends to go up 20% in value and so on.

当β值等于2时，If，β,表明若市场组合增值，股票价值就增长了20%，以此类推。

耶鲁公开课 - 金融市场课程节选