missice1117 · 2020年11月06日
* 问题详情，请 查看题干
问题如下：
Based on Exhibits 1 and 2, the effective duration for the AI bond is closest to:
选项：
A.1.98.
B.2.15.
C.2.73.
解释：
B is correct.
The AI bond’s value if interest rates shift down by 30 bps (PV–) is 100.78. The AI bond’s value if interest rates shift up by 30 bps (PV+) is 99.487.
Effective duration=[(PV-)-(PV+)]/[2× (ΔCurve) × (PV0)]= (100.780 - 99.487)/ (2 × 0.003 × 100.200)=2.15
这题用二叉树算出来down的PV是101.0386，up的PV是99.8508，算了两遍都是这样，不知道是哪里出了问题，或者答案的这两个数是怎么算出来的。。
吴昊_品职助教 · 2020年11月06日
同学你好：
有可能是忘了加OAS导致的答案错误。
当利率下降30bp时算出来的就是PV-，而PV+的情况类似，下面讲解以PV-为例。表2panelA给出的是benchmark的二叉树，要将AI这个债券的OAS=13.95bp 加到benchmark上面才是AI的二叉树。
债券第三年到期，将第三年的面值加上coupon折现到第二年年末的各个节点。得到的价值需要和行权价进行比较，看看是否会行权。我们可以看到在第二年末只有100.39大于行权价，所以将其调整到行权价100。然后以此类推将第二年年末的现金流加权平均往第一年折现。具体计算步骤如下：
NO.PZ201712110200000401 问题如下 Baseon Exhibits 1 an2, the effective ration for the bonis closest to: A.1.98. B.2.15. C.2.73. B is correct. The bons value if interest rates shift wn 30 bps (PV–) is 100.78. The bons value if interest rates shift up 30 bps (PV+) is 99.487.Effective ration=[(PV-)-(PV+)]/[2× (ΔCurve) × (PV0)]= (100.780 - 99.487)/ (2 × 0.003 × 100.200)=2.15 bons value if interest rates shift wn 30 bps (PV–) 我算的不是 100.78，而是101.03854，算了两次都是这样，请问我哪里出错了？
NO.PZ201712110200000401 问题如下 Baseon Exhibits 1 an2, the effective ration for the bonis closest to: A.1.98. B.2.15. C.2.73. B is correct. The bons value if interest rates shift wn 30 bps (PV–) is 100.78. The bons value if interest rates shift up 30 bps (PV+) is 99.487.Effective ration=[(PV-)-(PV+)]/[2× (ΔCurve) × (PV0)]= (100.780 - 99.487)/ (2 × 0.003 × 100.200)=2.15 老师您好，我看原教材解析里面都懒得写计算全过程了...... 一般考试中会出现这么繁琐的计算么
NO.PZ201712110200000401问题如下Baseon Exhibits 1 an2, the effective ration for the bonis closest to:A.1.98.B.2.15.C.2.73.B is correct. The bons value if interest rates shift wn 30 bps (PV–) is 100.78. The bons value if interest rates shift up 30 bps (PV+) is 99.487.Effective ration=[(PV-)-(PV+)]/[2× (ΔCurve) × (PV0)]= (100.780 - 99.487)/ (2 × 0.003 × 100.200)=2.15对于含权债券如何判断题目给的现金流是否含权，什么时候需要在分母加oas
NO.PZ201712110200000401 问题如下 Baseon Exhibits 1 an2, the effective ration for the bonis closest to: A.1.98. B.2.15. C.2.73. B is correct. The bons value if interest rates shift wn 30 bps (PV–) is 100.78. The bons value if interest rates shift up 30 bps (PV+) is 99.487.Effective ration=[(PV-)-(PV+)]/[2× (ΔCurve) × (PV0)]= (100.780 - 99.487)/ (2 × 0.003 × 100.200)=2.15 老师上课说过，OAS是剔除了权利影响的sprea分子的现金流已经包含了权利影响了。那为什么还可以在二叉树的利率上直接加OAS，但是现金流又还是按照初始的coupon rate来计算呢？
NO.PZ201712110200000401 问题如下 Baseon Exhibits 1 an2, the effective ration for the bonis closest to: A.1.98. B.2.15. C.2.73. B is correct. The bons value if interest rates shift wn 30 bps (PV–) is 100.78. The bons value if interest rates shift up 30 bps (PV+) is 99.487.Effective ration=[(PV-)-(PV+)]/[2× (ΔCurve) × (PV0)]= (100.780 - 99.487)/ (2 × 0.003 × 100.200)=2.15 例如上图是辅导老师的解题过程，V+在year2，既然折现率4.9377%小于coupon rate，作为callable，为什么不直接取100呢而是99.7114？
