Narration: AI voice.
Two strikes on one page
Two strikes. Most SPX gamma charts draw them. Call wall above the price. Put wall below it. SquawkFlow publishes both, every trading day, free, no account. Here's the read off that page, as captured on October 16, 2026. What they are. And what they're not.
Reading the levels tile
Here's the levels tile. Top line, SPX spot: 7,663.20, with its own timestamp. Call wall: 7,900. Put wall: 7,650. Zero gamma flip: 7,729. The header tells you when the tile was captured. First habit. Every level gets read with its time. Now the paragraph under the tile. It tells you where the numbers come from. Cboe open interest, settled October 15, 2026. Open interest gets published once a day, after the close. So these walls are positioning carried into the session. Not trades made during it.
What the walls are
Definitions. Call wall: the strike above spot with the most call gamma. Put wall: the strike below spot with the most put gamma. That's gamma-weighted open interest, not raw contract count. A nearby strike with moderate size can beat a far strike with more contracts. Some services rank the biggest put open interest instead. Different number, sometimes a different strike. Check what a service ranks.
The call wall, from the delta
Why would a strike act like a ceiling? One fact. A call's delta climbs toward one as the underlying rises. Dealer short that call? They add to a long hedge as price climbs. That pushes the move. Short gamma. Dealer long the call? They add to a short hedge into the rally. That slows it. Long gamma. So the call wall is resistance only if dealers are long those calls. The standard convention, and the one this page uses, assumes they are.
The put wall is not a mirror
Now the put side. This is where most explainers get it backwards. Customers own index puts. Dealers are mostly short them. A short put's delta gets more positive as price falls. So a delta-neutral desk adds to its short hedge into the drop. That's pressure with the move. Not support. So why can a put wall look like a floor? Four reasons. One, hedge exhaustion. Price trades through, the puts go deep in the money, the hedging stops. Two, position closing. Protection bought out of the money gets closed near the strike, and dealers cover their hedges. Three, vanna. A test fails, implied vol comes in, put deltas shrink, and dealers unwind part of the short. Four, distance. A level way below spot just doesn't get tested most days.
Two reads on the same page
Scroll down. There's a second read, repriced at Oct 16, 13:30 ET. Same settled open interest. Revalued at that hour's spot instead of the morning one. The settled read up top says call wall 7,900, put wall 7,650. The repriced block has its own levels, so read each one with its time. Positions didn't change. The spot used to weigh them did.
What the page does not tell you
Everything here rests on one assumption. Open interest tells you a contract exists. Not which side the dealer is on. No exchange publishes dealer inventory. Researchers who rebuilt the actual market maker book in SPX from Cboe records found its gamma typically positive. But often negative. On those days a wall drawn from the convention can point the wrong way. Notice what's missing. No hold rate. The one this page used to show was pulled in August. One number was blending near walls with far ones. Instead, there's a session log. What happened, time by time. Build your own count.
Wrap
Bottom line. Read every wall with its time and its distance from spot. The call wall is resistance only if dealers are long the calls. Put wall support comes from exhaustion, closing, vanna and distance. Not from hedging short puts. And all of it rests on an assumption nobody can verify. Full write-up, every source, on the learn page linked with this video. Education, not advice.
Full write-up with sources: /learn/call-wall-put-wall-explained
Educational content, not investment advice.
Levels shown are as captured on 2026-10-16 13:34 ET; they are not current.