在做notes时,发现第五本书P128 Q10与P160 Q10是相互矛盾的。
矛盾如下:如果Z-spread > OAS , 即cost of option >0, 这种情况应该是put option 还是 call option ?
书中解释:for callable bonds, cost of option >0 ,you receive compensation for writing the option to the issuer, so OAS>z-spread;
还写道:in other word, you require more yield on the callable bond than for an opton-free bond, 如果要求的收益率更高的话,OAS应该大于z-spread才对呀?不太理解,哪位高手解释一二? 不胜感谢!!