1
vote
1answer
64 views

Why doesn't VG flatten volatility skew for short term options?

The VG process, from my inexpert point-of-view, seems to nearly perfectly model equity distributions. For longer term options, there is little to no volatility, skewness, or kurtosis parameter skew. ...
1
vote
0answers
274 views

Interpolate option volatility in delta space in R

I have a bunch of deltas and option implied vols at those deltas. I would like to interpolate them in R. Interpolating them in delta space seems difficult, since normally you would like the ATM calls ...
3
votes
1answer
390 views

Why does Skew measure remain more-or-less constant for Listed Expiries?

I have looked at the Variance Swap Papers published by GS-VarSwap and JPM-VarSWap where they talk about approximation to VarSwap strike using ATMF vol and Skew (slope of the volatility skew for 90-110 ...
8
votes
1answer
399 views

Option Portfolio Risk - Volatility/Skew - practical implementation

I'm trying to improve my methods for calculating real-time US Equity option portfolio risk. My main problem is volatility "stability" across all strikes in an option series. The current ...
9
votes
5answers
5k views

What is the implied volatility skew?

I often hear people talking about the skew of the volatility surface, model, etc... but it appears to me that a clear standard definition is not unanimously in place among practitioners. So here is ...