GEX is a model
Open interest is observed. Spot is observed. Option prices are observed. GEX is an estimate built from those observations with assumptions about Greeks, contract size, expiry selection, and dealer positioning.
That makes GEX useful but not absolute. It belongs in the model layer of session math, not the same layer as a directly counted value.
Recipe differences
One chart may include only the nearest Tuesday expiry. Another may include multiple expiries. One may apply a dealer-sign assumption to customer positioning. Another may present call and put gamma differently.
Small choices can change the total, the flip zone, and the visual concentration around strikes. The disagreement is often a recipe difference rather than an error.
Data timing matters
Nifty F&O data changes during the session. OI updates, price updates, and IV updates do not always arrive at the same cadence across tools.
A chart refreshed at a different moment can disagree with another chart even before model assumptions enter the picture. That is especially visible near Tuesday weekly expiry.
What to compare
Instead of comparing only the headline number, compare the shape. Where are the largest concentrations? Is spot near a modelled boundary? Is the map broadly dampening or unstable around current price?
If two charts disagree on the exact total but agree on the broad regime, the practical read may be similar. If they disagree on the regime, slow down and use the reliability ladder.
How to avoid chart fights
Do not turn GEX into a uniqueness contest. A chart is a lens. The useful habit is to know the lens, its inputs, and its limits.
Use futures structure, session POC, and OI change as companion lenses. If the full stack does not agree, the correct conclusion may simply be that the session read is less clean.
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Get Started for FreeFAQ
Why do two Nifty GEX charts show different numbers?
They may use different expiries, refresh times, Greek calculations, strike filters, or dealer-sign assumptions.
Does disagreement mean one chart is fake?
Not necessarily. GEX is modelled session math, so different recipes can produce different but still explainable maps.
Should I trust the exact GEX number?
Treat it as an estimate. The shape, concentration, and distance from spot are usually more useful than the exact total.
Does Tuesday expiry make disagreement larger?
It can. Near Nifty weekly expiry, OI and Greeks can change quickly, so refresh timing and expiry selection matter more.
What if charts disagree on the flip zone?
Read the boundary as a region and use other lenses such as futures tape, session POC, and OI change before forming a session view.
Is GEX a trading signal?
No. It is context for the Nifty F&O session. Read it. Don't trade it.
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