Both, but most retail traders rarely consider it even though it is very important:Quote from erol:
I apologize in advance for my stupid question, but I recall in Natenberg's book stating that vega was supposed to be the sensitivity to the underlying . I'm confused, is it the underlying or the IV?
Thanks
Quote from nitro:
Both, but most retail traders rarely consider it even though it is very important:
Vanna = dVega/dSpot = dDelta/dVola = the rate of change in vega for a given change in spot (d means partial derivatives.)
Vomma = dVega/dVola (the "gamma" of vola)
etc...
It is imperative in skew plays.
Quote from erol:
I prefer books since they're more comprehensive and I find go into better details.