Which of the following statements regarding the option adjusted spread (OAS) is most accurate? The option adjusted spread: A is the spread added to the Treasury spot rate curve that the bond would have if it were option-free. B is the spread that accounts for non-option characteristics like credit risk, liquidity risk, and interest rate risk. C for a putable bond is the Z-spread plus the cost of the option putable coast=ZS-option cost 还是ZS option cost? callable cosat = 什么？

老师，我想问下这道题的题意和解析部分，看了视频也没看懂。

老师您好，我一直不太明白汇率对于通胀的影响，还有就是汇率影响进出口的机制是什么，本币和外币的升降值对通胀的影响是站在本币还是外币的角度来说的

老师您好，请问视频中讲样本方差的分母是n-1时讲到自由度举例说四个数1，2，3，x, 均值2.5，x=4,不理解怎么看出自由度是3的？

权证可以同时持有股票和期权，那股票和期权是否是等值的呢？？

税率改变不需要retrospective调整吗

老师，这里的SFAS和US.GAAP是不是都是表示美国会计准则？下面的IAS和IFRS都是国际会计准则的意思？

老师，请问disadvantage中第二，第三点讲的是什么意思？

老师，请问为什么structure portfoilo to be more sensitive to long-term interest rate and less sensitive to short-term interest rate？不是短期利率波动比长期大更敏感吗？

怎么区分原函数和反函数