Put wall
A put wall is the strike below spot carrying the largest put concentration under a provider's chosen metric, whether open interest or modeled gamma. Like a call wall it marks where contracts cluster, not where support is guaranteed, and its implied hedging behaviour depends on a positioning assumption the data does not confirm.
Senzoukria · Glossary · Updated September 2026
Where the puts cluster and why
Puts below spot are often held as protection, and the chain shows where that open interest clusters, frequently at round strikes. A put wall is the strike where that concentration is largest inside the chosen expiry scope. Under the usual dealer convention the dealer is long those puts, but that is a modeling choice, not a report; the wall's strike is a fact of the chain while its sign is an assumption.
Open interest and gamma can disagree
The lower strike has the larger contract count; the nearer strike has the larger gamma-weighted magnitude under these invented inputs. A provider ranking by open interest names 95 as the put wall; one ranking by gamma names 98. Neither is wrong, but they are not interchangeable, and a page should not silently relabel one measure as the other.
| Strike | Open interest | Gamma per $1 | OI × gamma × 100 |
|---|---|---|---|
| 95 | 12,000 | 0.004 | 4,800 |
| 98 | 5,000 | 0.028 | 14,000 |
Reading a put wall against the futures tape
- Map the strike onto the futures contract first when the chain is on SPX or SPY and the chart is ES.
- Write down the source, timestamp, expiry scope and selection rule before price approaches.
- At the level, read executed bid volume against ask volume per price and watch whether the resting bid absorbs or pulls; those are separate observations from the wall.
- Log failures as well as holds under the same rule; a held level does not identify its cause.
In Senzoukria
The GEX module reports a Put wall on the Overview and draws it on the chart as the Put Wall key level, together with Zero Gamma and Call Wall. It is selected as the put-dominant strike below spot within the current expiry scope and 0DTE handling; if no strike below spot is put-dominant, the module states that condition and leaves the level empty. The regime panel shows the Put / call OI ratio for context, and the Net GEX by strike page separates the Puts contribution from the Calls contribution at each strike so the reader can judge whether the wall is a contract-count concentration or a gamma concentration. The How firm the key levels are section gives a band for how far the put wall shifts across the assumptions tested.
Common mistakes
- Calling the put wall a floor. It is a concentration, and price can trade through it with no dealer involvement.
- Ignoring that the wall can roll lower as protection is rolled down during a decline.
- Reading a high put/call open-interest ratio as bearish on its own; puts are bought and sold for many reasons.
Related
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Frequently asked questions
- Is a put wall support?
- Not by definition. It is the strike below spot with the largest put concentration under a chosen metric. A hold at that level may coincide with hedging, with resting bids or with unrelated flow, and the data does not separate them. Treat it as a reference to test against executed volume, not as a guaranteed floor.
- How does the put wall differ from the zero gamma level?
- The put wall is a strike selected by concentration; the zero-gamma level is the root of a net exposure curve as hypothetical spot varies. They are usually at different prices, and the put wall is often well below the flip. A large put strike does not have to be the largest gamma strike either.
- Why does Senzoukria sometimes show no put wall?
- Because its rule requires a put-dominant strike below spot inside the selected scope. When every strike below spot is call-dominant, or the scope leaves no strike at all, the module reports that reason instead of forcing a level. An absent level is shown as absent, not as zero.