I would go with e) None of the above.Quote from Optionspoet:
Hi everyone,
I remember most of you from the Yahoo days and was hoping to tap into the knowledge of the greeks that most of you have. A theoretical question has surfaced that I could not find any direct way of confirming the correct response. The analogy is as follows:
Which of the following best expresses a relationship similar to Delta : Price??
a) Gamma : Delta
b) Vega : Volatility
c) Theta : Time
d) Rho : Interest Rate
e) None of the above.
I have strong inclination towards (b) since delta measures the rate of change in option price relative to a change in the underlying's price and vega measures the rate of change in the option price relative to a change in the underlying's volatility.
I'm nixing the other choices because Gamma : Delta expresses an indirect effect on options price. Gamma affects delta which affects price, but does not relate directly to price as in the analogy. All the others measure a change relative to some other external factor (time decay, rates).
Please let me know if my logic is correct.
Many thanks in advance.
If my answer is wrong, then their are two other logical choices a) or b). Because like delta both of these define a change in their target parameter.
In summary, because one line of thinking has two possible answers I'd probably go with the logic that has only one answer "d)". Reinforcing "d)" might be that delta has nothing to do with theoretical price (okay it does define the change in TP).
Gotta say it's a poorly worded question.
Don

however a rather vivid example of the new BP we could have