If the yield curve moves up, putable bonds decrease in value, just not by as much as a comparable straight bond would. Putable bonds are composed of 2 parts: the straight bond and the embedded put option. Although it is true that increasing rates would cause the value of the put option to increase, there is still the inverse relationship between interest rates and bond prices, which would cause the straight bond portion of the putable bond to decrease. So, the put option will increase in value, but not by enough to offset the decrease in price of the bond as a whole. The net effect is that as interest rates go up, putable bond prices still go down.