Why GEX dashboards disagree
GEX dashboards disagree because gamma exposure is a modelled quantity whose result depends on the expiry scope, the dealer-sign assumption, the pricing model, the open-interest snapshot, the spot and volatility inputs and the units chosen. Two providers reading the same chain with different choices will publish different totals, walls and flip levels without either being wrong.
Senzoukria · Glossary · Updated September 2026
The choices that move the numbers
| Choice | Typical alternatives | Effect |
|---|---|---|
| Expiry scope | 0DTE only, nearest expiry, all listed expiries, monthlies only | Different portfolios; walls and flip move |
| Dealer sign | Dealers short gamma vs dealers long gamma | Totals flip sign; the regime reading reverses |
| Pricing model | Black-Scholes, Black-76, binomial | Gamma per leg differs; levels shift a few points |
| Open-interest snapshot | Previous close vs an older file | Positions differ by a full day of trading |
| Spot and volatility inputs | Live, delayed or stale quotes; implied vs assumed vol | Gamma recomputed on different prices |
| Units | Per 1% move, per $1 move, contract units | Totals not comparable at all |
| Underlying and mapping | SPX vs SPY; basis and ETF ratio when shown on ES | Same concept, different price scale |
Timing disagreements
Open interest is published once a day after the close. Two dashboards that refresh the chain at different moments during the session show different spot, different time to expiry and therefore different gamma, on identical positions. Near expiry small changes in spot change gamma quickly, so intraday disagreement is largest on days with heavy same-day expiry. A delayed options feed adds a further offset that a dashboard may or may not disclose.
How to compare two dashboards honestly
- Match the underlying first: SPX, SPY and the ES options are different chains with different positioning.
- Match the expiry scope and the 0DTE handling.
- Match the units before comparing headline totals.
- Compare snapshot times for both open interest and quotes.
- Only then compare levels, and expect a residual gap from the pricing model and root-search method.
In Senzoukria
The GEX workspace makes each of these choices explicit in its Calculation assumptions panel: dealer positioning, expiry scope, 0DTE handling, pricing model, risk-free rate and dividend yield. Changing a choice recomputes the levels in place, so the effect of an assumption can be seen rather than guessed.
A section titled How firm the key levels are recomputes zero gamma, the call wall and the put wall with the expiry scope and the 0DTE choice varied, and reports the spread as a band. A level that barely moves is labelled stable; one that moves a lot is labelled as a zone to be read rather than a line. The panel describes this band as a sensitivity, not a confidence interval. Data freshness shows the chain snapshot time and the spot time, and when the cumulative gamma never crosses zero the panel reports that instead of inventing a flip.
Common mistakes
- Averaging levels from two providers with different scopes.
- Treating the provider whose level reacted once as the correct one.
- Reading a delayed chain's level as live.
- Assuming a missing flip is a bug rather than a curve that stays on one side of zero.
Related
- What GEX measures
- Zero-gamma flip explained
- GEX dashboard
- GEX calculation and units
- Mapping SPX/NDX levels to ES/NQ
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Frequently asked questions
- Which GEX dashboard is right?
- The question does not have an answer in that form. Each dashboard is right about its own model given its inputs. What can be checked is whether a dashboard discloses its expiry scope, dealer-sign assumption, pricing model, units and snapshot times. Without those, its level cannot be compared with anything, including with itself on another day.
- Why does my dashboard's flip differ from the one on the strike chart?
- Two different computations can both be called a flip. One takes the cumulative sum of today's net GEX by strike and finds where the running total crosses zero; the other reprices every leg at a range of hypothetical prices and finds where that profile crosses zero. They generally land at different prices. A dashboard should say which one it draws.
- Should I widen a gamma level into a zone?
- Yes, when the level moves under reasonable changes to the assumptions. Recomputing the level with a different expiry scope or 0DTE treatment gives a spread; that spread, added to any mapping uncertainty on futures, is the width of the zone. A level that hardly moves can be drawn tighter.