Understand modeled dealer exposure

Start with a sensitivity question

Open Gamma when you want to investigate how an options chain's modeled sensitivities are distributed. Exposure tools summarize a selected chain using a positioning convention. They do not show an exchange account's inventory. Start by asking whether you want sensitivity by strike, by expiration, across hypothetical spot prices or through time. Those questions lead to different tools even when their metric pill says GEX.

Build a controlled comparison

Use one underlying and a broad expiration selection before narrowing the analysis. Keep a note of the initial model, perspective and unit so a later filter change has an interpretable effect.

1. Open Gamma → Overview and choose the underlying, session and trading date.
2. Choose a metric in an exposure tool and read its unit.
3. Inspect the model and perspective settings.
4. Match those choices in a second tool before comparing totals.
5. Change one setting at a time and observe which dimensions changed.

Read sign, magnitude and location separately

Magnitude measures the selected sensitivity under its unit, sign describes the selected convention, and strike or expiration describes where it is concentrated. A small net value can coexist with large opposing call and put aggregates. Gross concentrations can therefore answer a different question from net concentrations. A single colored bar cannot establish the market's next direction; read the side breakdown and the scope of the total before applying a directional interpretation.

Worked interpretation: same chain, different outputs

Suppose a selected strike has a large positive call contribution and a similarly sized negative put contribution. Its net exposure can be small while its gross concentration is substantial. Switching to a customer perspective can negate signed values without creating a new set of executed trades. Switching from GEX to DEX changes the sensitivity and units, so a smaller displayed number is not evidence that positioning vanished. Compare each output with its own baseline rather than dividing unlike metrics together.

Investigate apparent contradictions

If two tools disagree, first compare date/minute, expirations, right selection, model and units. Then check whether one total covers the complete selected chain while another plot shows only a bounded strike window. If a Greek is unavailable, do not interpret a retained gamma reference as that Greek's substitute. A screenshot for support should show the selection chips, metric, legend and quality state so the model can be reproduced.

Model, perspective and units

Exposure is a sensitivity calculation, not an execution total. GEX means gamma exposure, DEX means delta exposure, VEX means vanna exposure, and CEX means charm exposure; charm can also be called CHEX. VEX does not mean vega in these tools. Select the metric before comparing colors or magnitudes. Per 1% move, per $1 move and per unit are distinct choices. Read the returned unit rather than assuming that every displayed dollar amount means money paid for contracts.

Classic OI applies a positioning proxy to dated open interest. Flow-adjusted modeling incorporates eligible classified intraday volume into that proxy. Neither reveals actual dealer inventory or every hedge. Dealer and customer perspectives can reverse signs while retaining the underlying sensitivity calculation. A positive bar is therefore meaningful only with its metric, model, perspective, expiration selection and valuation time. Record those settings together when sharing a view, and match them before expecting two tools to return comparable values.

Choose the tool that matches the question

For a strike concentration, start with Exposure by Strike and then inspect its expiration composition. For a maturity concentration, reverse that order. For sensitivity to a hypothetical underlying move, use Gamma Curve rather than extending a current strike bar across prices. For a session sequence, use Interval Map or Levels / Time. Those axes represent different dimensions: strike, expiry, hypothetical spot and observed valuation time. Choosing the wrong dimension can produce a plausible chart that does not answer the intended question.

A practical review can begin at Key Levels, identify one concentration, isolate its expiry in the strike chart, and inspect its historical behavior with the same model selection. Write down what each transition establishes. A large rank locates modeled magnitude; a curve tests a repricing convention; a historical line documents eligible model outputs. None independently proves a future hedging transaction. This sequence produces a traceable analytical explanation rather than relying on a headline label such as positive gamma to describe every condition in the workspace.