老师好，这里不明白，为什么回归里为什么X与残差有关系，异方差就存在？ 同样，为什么自回归里，残差t与残差t-1有关系，得出异方差就存在？异方差不是指残差的方差不恒定吗？

请问Jason‘s alpha 是哪里讲过的？在哪里能看到

prediction3中为什么是higher

目前为止，组合的题目的正确率最差，有点不知道这门课怎么学了，哎。。。 图片里的题目，经济衰退时候不是应该选非周期行业的大盘价值股才能有比较满意的结果吧，三个选项我选不出。。。

realized return韩老师说是年化的。课后题答案却是非年化

题干见图片 Q. Based on Quantum’s economic forecast and the data in Exhibit 1, which bond is Coombs most likely to recommend as the short position for the hedge fund? Bond 3 Bond 1 Bond 2 请老师比较下bong1和2，我没有明确的判断出选择项，这两个比较有的指标好有的指标差。

mark-to-market value 里面的r 为什么是标价货币的利率？远期汇率定价公式里是（基础货币拆解利率-标价货币拆解利率）

A macro topic for this week’s fixed-income committee is the possibility that the US Federal Reserve Board (Fed) will raise the federal funds rate (FFR) 25 bps at their next meeting. Quantum’s committee believes that the Fed is likely to hold off raising the FFR for at least six months because of weak economic data, and that weakness will be seen in the upcoming payroll numbers. Quantum expects the monthly non-farm payroll report to show that the US labor market added only 90,000 jobs this month, roughly in line with consensus expectations. The committee is debating what will happen to the short end of the US yield curve (and what will happen subsequently to short-dated bond prices) if the payroll report comes in at the level they expect. 题干部分如上，题目如下 Q. Which of the following is the most likely impact on short-term bond prices if Quantum’s expectations regarding the payroll report are correct? No change Fall Rise 这题我选的是fall，但是答案是no change哎，请老师解答，不太懂经济下行期为啥不是fall

老师好，fintech和machine learning的干货，知识框架有嘛？我课也听了 ppt也打印了 题也做了 （虽然基本都蒙对了） 但是依然不知道要记什么？

老师好 为什么先用DF检验再用DF-EG检验呢？前一个是干什么用的 后一个是干什么用的？