Duration of bond option

= (delta of call option) × (duration of underlying) × (price of underlying) / (price of call option)

trying to make sure I understand this intuitively.

the 1st 2 segments make sense to me. You multiply a sensitivity factor (delta) to the underlying’s duration.

why do you then include the third component? Thanks.

Think of of this way…

delta = Dollar duration of options/ dollar duration of underlying

Here is the intuition behind the formula but it’s better just memorize the formula:

Bond Option Duration = - %delta_BOpt / delta_Y = - (delta_BOpt / BOpt) / delta_Y =

= (delta_BOpt / delta_B) * [-(delta_B / B) / delta_Y] * (B / BOpt) =

= BOpt_Delta * Bond_Duration * B / BOpt

B - bond price

BOpt - Bond option price

Y - interest rate