Thank you. Didn't expect it but really appreciate this post.Upside flies benefit from vol-corr and lose to sticky D in index. This week is a prime example (where it fails) due to the risk of govt-shutdown.
Sep29 figures:
25D put: 19%
ATM: 16.3%
25D call: 14.6%
You cannot assume that ATM vols will converge to the 25D figure on a touch due to macro/political risk unless a deal is made. IOW, do not mark down vol due to vol-corr when there is specific macro-risk. Generally, you can ignore the vol line when you're betting on pinning as the things are all gamma this close to expiration.
When trading >1M out the vol-surface is dominant.
So I tell people to focus on achieving neutrality when trading long flies (natural/vert-flies) with 1W-1M. Go with upside flies when trading vol-corr (absent known events), and narrow OTM diagonals (locally long gamma) when trading into bear targets.
Into macro? Wide ATM flies strangled (guts) say, 4310-4410 bull and 4230/4330 bear. You can see that the skew is fairly substantial as the call fly is the revenue side of the reversal (reflects down/out skew) shown by the large debit.
View attachment 323677
I don't fully understand but there is enough for me to chew on so I won't pester you with more questions.
Best regards.
