为什么期货价格下降，保证金账户会下降？

不太明白为什么FRA的价格利率图是个曲线，老师是用损益来考虑的，但损益公式也不是个二次曲线啊？

Three months ago (90 days), Kim purchased a bond with a 3% annual coupon and a maturity date of seven years from the date of purchase. The bond has a face value of US$1,000 and pays interest every 180 days from the date of issue. Kim is concerned about a potential increase in interest rates over the next year and has approached Riley for advice on how to use forward contracts to manage this risk. Riley advises Kim to enter into a short position in a fixed-income forward contract expiring in 360 days. The annualized risk-free rate now is 1.5% per year and the price of the bond with accrued interest is US$1,103.45.这道题是协会官网题目，有点搞不清楚各种时间。case说90天以前买了债券，现在想买1年的远期合约，为什么定价还是给360天的远期合约定价呢？不应该是450天以后吗？

卖出时，看基金的持仓来交税是指卖出的份额交税吗？

这老师这道题的视频讲解还不如看文字解析，表达很不清楚

视频里老师对c答案的解析不对

𝑓(𝑨,𝑩−𝑨)=100−(100×𝑀𝑅𝑅(𝐴,𝐵−𝐴))这个报价公式来源和原理没有介绍，只是了解一下就好么？

Q4, 想问一下这句话 "The log price differential referred to as the spread of their share prices shows mean reversion over the last decade. The spread is currently two standard deviations from the moving average. " 是什么意思？ 以及和moving average有两个标准差应该如何理解？

没太明白，为什么期货合约的估值，要减去futures price at the last mark- to- market time？

老师，费用为什么可以加回net income。我的理解是，应该从net income里减去费用吖？