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？

老师您好，请您解释一下优点的第二条。就是相关系数的那条。

老师您好，请您解释一下为什么标准差的换算是除以根号12或者根号52？ 不是直接应该不用开根号了吧？？方差是平方，但是标准差就直接不需要平方也就是应该是线性关系啊！

老师，Reading21 课后题38题，答案是B，但是在算MVA时，答案中给的数字44,055 好像错了，应该是37,245吧？答案中第五年的EP算错了，寻求证！