问题如下图：
选项：
A. 
B. 
C. 
解释：
按照课程中介绍的OAS或者 OAY，Callable Bond权利执行后（剔除权利后）， OAY< YTM，但是27-30题可以看出，执行权利后的Yield to 1st/2nd call 都比YTM大啊，是不是和结论矛盾呢？
吴昊_品职助教 · 2019年03月05日
同学，这是完全不同的概念。这些题目中求得yield to first call，yield to second call只是说callable bond被发行人提前赎回以后可以得到的收益率。如果五年期的债券第一次可赎回在第三年，那我们算的就是在第三年债券赎回获得的收益率。
callable bond: OAS＜ZS。OAS是剔除掉权利影响之后的spread。callable bond中含有的是对投资者不利的权利，所以我们需要给投资者更高的补偿，那我们把这个不利的权利剔除掉之后，投资者就不会要求这么高的补偿了，所以OAS小于z-spread。
加油~
NO.PZ2016031001000080 问题如下 A bonwith 5 years remaining until maturity is currently trang for 101 per 100 of pvalue. The bonoffers a 6% coupon rate with interest paisemiannually. The bonis first callable in 3 years, anis callable after thte on coupon tes accorng to the following schele: The bons yielto-worst is closest to: A.2.88%. B.5.77%. C.6.25%. B is correct.The yielto-worst is 5.77%. The bons yielto-worst is the lowest of the sequenof yiel-to-call anthe yielto-maturity. From above, we have the following yielmeasures for this bonYielto-first-call: 6.25%Yielto-seconcall: 5.94%Yielto-maturity: 5.77%Thus, the yielto-worst is 5.77%.考点YTW解析本题让计算 yielto-worst，所以需要计算出每种情况下的收益再进行对比。1、对于 yielto-maturity:N=10；PV= -101；PMT=3；FV=100 → CPTI/Y =2.8835，但是要注意这是半年付息一次，所以年化后的 I/Y是5.767%2、对于 yielto-frist call:N=6；PV= -101；PMT=3；FV=102 → CPTI/Y =3.1229，所以年化后的 I/Y是6.246%3、对于 yielto-seconcall:N=8；PV= -101；PMT=3；FV=101 → CPTI/Y =2.97，所以年化后的 I/Y是5.94%所以对比最差的是yielto-maturity，即5.77%，故B正确。 call price对应的是FV，101是价格，对应的是PV。为啥不是call price对应的是PV，到期时的100是FV这样算呢？N也有所不同
NO.PZ2016031001000080 问题如下 A bonwith 5 years remaining until maturity is currently trang for 101 per 100 of pvalue. The bonoffers a 6% coupon rate with interest paisemiannually. The bonis first callable in 3 years, anis callable after thte on coupon tes accorng to the following schele: The bons yielto-worst is closest to: A.2.88%. B.5.77%. C.6.25%. B is correct.The yielto-worst is 5.77%. The bons yielto-worst is the lowest of the sequenof yiel-to-call anthe yielto-maturity. From above, we have the following yielmeasures for this bonYielto-first-call: 6.25%Yielto-seconcall: 5.94%Yielto-maturity: 5.77%Thus, the yielto-worst is 5.77%.考点YTW解析本题让计算 yielto-worst，所以需要计算出每种情况下的收益再进行对比。1、对于 yielto-maturity:N=10；PV= -101；PMT=3；FV=100 → CPTI/Y =2.8835，但是要注意这是半年付息一次，所以年化后的 I/Y是5.767%2、对于 yielto-frist call:N=6；PV= -101；PMT=3；FV=102 → CPTI/Y =3.1229，所以年化后的 I/Y是6.246%3、对于 yielto-seconcall:N=8；PV= -101；PMT=3；FV=101 → CPTI/Y =2.97，所以年化后的 I/Y是5.94%所以对比最差的是yielto-maturity，即5.77%，故B正确。 是不是callable bon的YTW一般都是YTM？
NO.PZ2016031001000080问题如下 A bonwith 5 years remaining until maturity is currently trang for 101 per 100 of pvalue. The bonoffers a 6% coupon rate with interest paisemiannually. The bonis first callable in 3 years, anis callable after thte on coupon tes accorng to the following schele: The bons yielto-worst is closest to:A.2.88%.B.5.77%.C.6.25%. B is correct.The yielto-worst is 5.77%. The bons yielto-worst is the lowest of the sequenof yiel-to-call anthe yielto-maturity. From above, we have the following yielmeasures for this bonYielto-first-call: 6.25%Yielto-seconcall: 5.94%Yielto-maturity: 5.77%Thus, the yielto-worst is 5.77%.考点YTW解析本题让计算 yielto-worst，所以需要计算出每种情况下的收益再进行对比。1、对于 yielto-maturity:N=10；PV= -101；PMT=3；FV=100 → CPTI/Y =2.8835，但是要注意这是半年付息一次，所以年化后的 I/Y是5.767%2、对于 yielto-frist call:N=6；PV= -101；PMT=3；FV=102 → CPTI/Y =3.1229，所以年化后的 I/Y是6.246%3、对于 yielto-seconcall:N=8；PV= -101；PMT=3；FV=101 → CPTI/Y =2.97，所以年化后的 I/Y是5.94%所以对比最差的是yielto-maturity，即5.77%，故B正确。 请问老师 为什么yeof 5 不用计算呢
NO.PZ2016031001000080 问题如下 A bonwith 5 years remaining until maturity is currently trang for 101 per 100 of pvalue. The bonoffers a 6% coupon rate with interest paisemiannually. The bonis first callable in 3 years, anis callable after thte on coupon tes accorng to the following schele: The bons yielto-worst is closest to: A.2.88%. B.5.77%. C.6.25%. B is correct.The yielto-worst is 5.77%. The bons yielto-worst is the lowest of the sequenof yiel-to-call anthe yielto-maturity. From above, we have the following yielmeasures for this bonYielto-first-call: 6.25%Yielto-seconcall: 5.94%Yielto-maturity: 5.77%Thus, the yielto-worst is 5.77%.考点YTW解析本题让计算 yielto-worst，所以需要计算出每种情况下的收益再进行对比。1、对于 yielto-maturity:N=10；PV= -101；PMT=3；FV=100 → CPTI/Y =2.8835，但是要注意这是半年付息一次，所以年化后的 I/Y是5.767%2、对于 yielto-frist call:N=6；PV= -101；PMT=3；FV=102 → CPTI/Y =3.1229，所以年化后的 I/Y是6.246%3、对于 yielto-seconcall:N=8；PV= -101；PMT=3；FV=101 → CPTI/Y =2.97，所以年化后的 I/Y是5.94%所以对比最差的是yielto-maturity，即5.77%，故B正确。 first call 是在 yeenof 3，那这个时候计算YTM , N 不是应该4吗，为什么是6？
5.77%. 6.25%. B is correct. The yielto-worst is 5.77%. The bons yielto-worst is the lowest of the sequenof yiel-to-call anthe yielto-maturity. From above, we have the following yielmeasures for this bon Yielto-first-call: 6.25% Yielto-seconcall: 5.94% Yielto-maturity: 5.77% Thus, the yielto-worst is 5.77%. 老师您好，您帮我看看看我错在哪里了？