含权债券的久期更低，但callable bond相当于给对方一个权利，可以额外收期权费，所以选callable，这个思路哪里不对

NO.PZ2021120102000004 问题如下 investment manager is consiring creasing portfolio rationversus a benchmark inx given her expectations of upwarparallel shift inthe yielcurve. If she ha choibetween a callable, putable, oroption-free bonwith otherwise comparable characteristics, the most profitableposition woulto: ownthe callable bon B.own the putable bon own the option-free bon B is correct. The value of a bonwith anembeeoption is equto the sum ofthe value of option-free bonplus the value to the embeeoption.With a putable bon the embeeput option isownethe boninvestor, who cexercise theoption if yiel-to-maturity increase, in this scenario.Unr the embeecall option is ownebythe bonissuer, who is more likely to exercise ifyiel-to-maturity crease (this, the boninvestor is short the calloption). for the option-free bonunrperformsthe putable bongiven the rise in value of theembeeput option. 老师讲过option free bonration比callable和putable bon大。同时，基础班讲义51页的例题问most profitable，老师说也就是选ration最大的。请问这道题为什么不是选ration的思路？以及这两道题结合在一起，什么时候根据ration最大、什么时候选含权债？

NO.PZ2021120102000004问题如下 investment manager is consiring creasing portfolio rationversus a benchmark inx given her expectations of upwarparallel shift inthe yielcurve. If she ha choibetween a callable, putable, oroption-free bonwith otherwise comparable characteristics, the most profitableposition woulto: ownthe callable bonB.own the putable bonown the option-free bon B is correct. The value of a bonwith anembeeoption is equto the sum ofthe value of option-free bonplus the value to the embeeoption.With a putable bon the embeeput option isownethe boninvestor, who cexercise theoption if yiel-to-maturity increase, in this scenario.Unr the embeecall option is ownebythe bonissuer, who is more likely to exercise ifyiel-to-maturity crease (this, the boninvestor is short the calloption). for the option-free bonunrperformsthe putable bongiven the rise in value of theembeeput option. 含权债券价格中callable bon利率升高的时候，call option价值下跌，负call option就相当于上升，为什么不能选？跟put option相比也没说那个价值大啊

NO.PZ2021120102000004 问题如下 investment manager is consiring creasing portfolio rationversus a benchmark inx given her expectations of upwarparallel shift inthe yielcurve. If she ha choibetween a callable, putable, oroption-free bonwith otherwise comparable characteristics, the most profitableposition woulto: ownthe callable bon B.own the putable bon own the option-free bon B is correct. The value of a bonwith anembeeoption is equto the sum ofthe value of option-free bonplus the value to the embeeoption.With a putable bon the embeeput option isownethe boninvestor, who cexercise theoption if yiel-to-maturity increase, in this scenario.Unr the embeecall option is ownebythe bonissuer, who is more likely to exercise ifyiel-to-maturity crease (this, the boninvestor is short the calloption). for the option-free bonunrperformsthe putable bongiven the rise in value of theembeeput option. 答案和题干中的降低ration有啥关系

NO.PZ2021120102000004问题如下 investment manager is consiring creasing portfolio rationversus a benchmark inx given her expectations of upwarparallel shift inthe yielcurve. If she ha choibetween a callable, putable, oroption-free bonwith otherwise comparable characteristics, the most profitableposition woulto: ownthe callable bonB.own the putable bonown the option-free bon B is correct. The value of a bonwith anembeeoption is equto the sum ofthe value of option-free bonplus the value to the embeeoption.With a putable bon the embeeput option isownethe boninvestor, who cexercise theoption if yiel-to-maturity increase, in this scenario.Unr the embeecall option is ownebythe bonissuer, who is more likely to exercise ifyiel-to-maturity crease (this, the boninvestor is short the calloption). for the option-free bonunrperformsthe putable bongiven the rise in value of theembeeput option. 对于含权债券来讲，profit的意思是行权才能获得profit，不行权就没有profit，是这样吗？