sinking fund structures and putables provide, protect, periods, against, understand

Chuckrox8

sinking fund structures allow issuers to execute a series of partial calls prior to maturity. investors use bonds with sinking fund structures to help protect against rising rates as a portion of the calls are mandatory. Thus this bonds may outperform bullets and callables during periods of rising rates.

putables are bonds where investors have a put option to demand full repayment at par. put structures provide investors with a defence against sharp increses in interst rates.


don understand1) why sinking fund structures help protect against rising rates
2) why putables provide investors with a defence against sharp increses in interst rates.
because if interest sink, putables will be putted, and what has this to do with increases in interst rates?