SPX
SPX · data through 2026-10-16 · free to read
SPX unusual options activity and options flow
What is the options flow saying about SPX?
On 2026-10-16, SPX traded $12.0B of call premium against $6.6B of put premium, 64% of it on the call side. The tape leans calls. Volume and open interest below, updated after each close.
The session's options tape
How much open interest is standing
Across 20 sessions to 2026-10-16, SPX carries 1.02M of call open interest against 1.91M of puts, a put/call ratio of 1.88. Open interest is what is still on the book, as opposed to what changed hands today.
Where the premium has gone over three months
From 2026-07-21 to 2026-10-16, cumulative call premium reached $343.6B against $217.7B on puts, a net of +$125.9B. One day's flow is noise; the cumulative line is where a lean shows up.
SPX gamma exposure
Where is dealer gamma on SPX?
As of 2026-10-16, dealer gamma on SPX is positive, so dealer hedging dampens moves. The sign has flipped 0 times over the window shown. A flip matters more than the level: it changes whether hedging flow works with the move or against it.
What dealer gamma has done
Total dealer gamma exposure on SPX over 20 sessions, 2026-09-21 to 2026-10-16. The sign flipped 0 times in that window.
When dealer gamma is positive, hedging leans against the move and tends to compress the range. When it is negative, hedging runs with the move and tends to extend it. The flip is the event worth watching, not the level.
Common questions about SPX
What does the options flow on SPX actually mean?
It is the money that changed hands in SPX options on 2026-10-16: $12.0B paid for calls, $6.6B for puts. Premium is the better read than contract count, because a thousand cheap far-dated calls and one large near-dated block are not the same conviction, and only premium tells them apart.
Is heavy call buying in SPX bullish?
Not by itself. 64% of SPX's premium sat on the call side, and a good share of any day's call volume is someone hedging a short, closing a position, or a market maker managing inventory. Flow says where money went, never why. It is one input among several, which is how it is weighted on the desk.
What is the difference between volume and open interest on SPX?
Volume is what traded today: 329338 calls and 507894 puts. Open interest is what is still on the book afterwards, currently 1.02M of calls against 1.91M of puts. Volume can spike and vanish the same day; open interest rising means positions were opened rather than closed.
What is dealer gamma exposure on SPX?
It is the aggregate gamma the market makers who sold SPX options are carrying. It matters because they hedge it, and that hedging is real buying and selling in the stock. As of 2026-10-16 it is positive.
What happens when SPX gamma is positive versus negative?
Positive gamma means dealers sell into strength and buy weakness, which compresses the range and makes moves fade. Negative gamma means they do the opposite, selling weakness and buying strength, which extends moves. Same stock, opposite character, depending only on which side dealers are on.
Why do the sign flips matter more than the level?
Because the flip is when the behaviour changes. SPX has flipped 0 times across the window shown here. A large positive number tells you little on its own; crossing zero tells you hedging flow just switched from working against the move to working with it.
More on SPX
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