@bennpeifert By fixed strike I assume you mean the same initial strike; if you redraw the skew curve at a higher atm vol and lower spot (equity skew) or lower atm vol and higher spot, the implied fix strike vol will be higher either way so I suppose the cov sign depends on spot up or down
@investinvol @bennpeifert Someone else made that point; I was thinking of the underlying that you use to measure delta. If it’s stock and not a future expiring on or close to the expiry of the option (or some calculation of forward), the delta of the call minus put doesn’t have to equal 1.
@bennpeifert 1) short wings in a short dated iron fly vs long wings in a long dated iron fly?
I feel like 2) is simpler in that it’s just long wings in an iron fly in a single expiry