你好 请问下原版书后题 98页 第19问 为什么A选项不正确呢 根据老师的讲解 pooling method会把合并前的收益计算进去

老师您好，第一张图片是apt模型的数据表，第二张图片是宏观要素模型的数据表。 我的问题是。 表格中的第二列都是expected return ...那么上课的时候老师说expected return在apt中是真实收益率，但是在第二张图中好像又是指的是预期收益率或者期望？ 请老师对着两个模型的公式分别给我说一下，这到底是对应真实收益率还是预期收益，谢谢。

Hello, instructor. I still cannot understand that if multicollinearity exists, there is a high R square (and significant F-statistic) even though the t-statistics on the estimated slope coefficients are not significant. looking forward to your response. Thanks.

请老师解释下为什么是ex ante？ 谢谢，

这个还是请老师解释下流动性那一条，谢谢

请老师解释下第三条，流动性那一条，谢谢

 if individual securities are affected by an assumption or forecast that persists through multiple rebalancing periods, then breadth will be lower, reducing the information ratio and thus the expected active return. 老师您请解释这是为什么？

The information ratio is a measure of relative expected or realized reward to risk, whereas the Sharpe ratio measures the absolute risk–return trade-off of a portfolio. 老师您好，我想问一下为什么夏普比率是绝对的？

原版书课后题 Reading 10，Q12 Because the value of the Durbin–Watson statistic is less than 2, we can say that the regression residuals are positively correlated. Because this statistic is fairly close to 2, however, we cannot say without a statistical test if the serial correlation is statistically significant。 r=0，DW=2，怎么是相关呢？

老师您好，请您解释一下红色波浪线的地方。期权这里是什么关系呢？