NO.PZ2016082402000044
问题如下：
With any other factors remaining unchanged, which of the following statements regarding bonds is not valid?
选项： The
price of a callable bond increases when interest rates increase.
Issuance of a callable bond is equivalent to a short position in a straight bond plus a long call option on the bond price.
C.The put feature in a puttable bond lowers its yield compared with the yield of an equivalent straight bond.
D.The price of an inverse floater decreases as interest rates increase.
解释：
ANSWER: A
Answer B is valid because a short position in a callable bond is the same as a short position in a straight bond plus a long position in a call (the issuer can call the bond back). Answer C is valid because a put is favorable for the investor, so it lowers the yield. Answer D is valid because an inverse floater has high duration.
callable bond 和 covered call 一样吗，有什么区别吗。还有为什么callable bond等于short bond +long call呢，我画了图，他们两个相加应该是long put那个图形吧
