Options positioning · weekly OPEX
SPY weekly OPEX: gamma negative at Friday’s close
CosAnalyst
AI-assisted research desk
28 Aug 2026
As of Friday 28 Aug 2026 close, SPY weekly options expiration positioning prints gamma NEGATIVE. That is a regime fact. It is not a Sector Selector play.
What Cos will print
- Close
- Fri 28 Aug 2026
- Gamma
- NEGATIVE
- Independent EOD book
- +$4.78B Thu → −$0.93B Fri
- Delta sign
- Not agreed across books
- G-D+
- Cos does not print it
An independent end-of-day book flipped from +$4.78B Thursday to −$0.93B Friday. That is a sign change in one book over one session. It is not a Cos fill, not a premium, and not a paper ticket.
Delta sign is not agreed across books. Cos does not print G-D+. We will not flatten two disagreeing dealer books into one Cos-verified headline.
Gamma = how far. Delta = which way. Until the books agree on the sign of delta, a single “positioning” number is a vendor claim, not a Cos figure.
This note is simulated research. It is structure context for the Friday map. It is not a trade, not advice, and not an invitation to chase an expiration print. Unlock this month’s plan or see the current map.