Use Interval Map through the session

Follow exposure across observed time

Interval Map plots exposure by strike through a session, with marks encoding magnitude and an underlying-price path as a reference. Time runs across buckets, while strike remains a price coordinate. This is different from a single-minute Heat Map: the chart asks how the selected model evolved as eligible dated inputs arrived. Open Gamma → Interval map or its Exposure tool in Map.

Set session and bucket period independently

The selected session chooses eligible observations; Period chooses how those observations are organized visually.

1. Choose the underlying, trading date and session.
2. Select the modeled metric, units and expiry scope.
3. Set the strike window around the area of interest.
4. Choose a bucket period that fits the session width.
5. Hover actual marks for their time, strike and value.
6. Compare the last forming column's observed valuation time with its bucket boundary.

The right edge is not a future observation

A forming live column can use a stable bucket-end boundary while its actual valuation and spot-source times advance. That boundary organizes the bucket; it does not mean the underlying price at that future instant has been observed. Compatible updates replace the forming column. Corrections, rollover or changed settings can require a full grid refresh. Gaps in the timeline remain gaps rather than invented intermediate exposure.

Worked interpretation: magnitude changes at one strike

Suppose a strike's marks grow over several buckets while the underlying moves nearby. Inspect the actual tooltip times and keep expiry/model settings fixed. The change can arise from valuation sensitivity, eligible flow adjustment or corrected model inputs; it does not automatically mean new OI appeared intraday. Switch to a coarser period to inspect the broader pattern, then return to the original period before comparing individual bucket values. A different aggregation should not be read as a new capture.

Troubleshoot sparse columns or stale hover

Confirm that the date has an eligible timeline and that preparation is complete. Check the strike range and metric before assuming blank time columns indicate zero exposure. Move the pointer off the plot when changing selection, then inspect a current mark so a delayed detail read is not mistaken for the new selection. For support include bucket period, hovered identity, source times and the visible history/coverage notice.

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 bucket width without inventing a finer history

A shorter period gives more temporal columns where eligible history exists; a longer period provides a broader visual summary. Neither setting guarantees more underlying observations. Inspect the detail time in a forming column: its bucket boundary can extend beyond the actual valuation timestamp. When comparing with an exact historical minute in another tool, use the observed valuation rather than the future end label. This is especially useful near rollover when the latest column is replaced or a new one begins.

A display price basis can map source strikes and the underlying path into eligible futures coordinates. That conversion does not add new options events. A moving basis can require a full mapped capture while the source history is still reused. If your comparison is about model magnitude, keep the original units and strike identity; if it is about projected price location, include the dated conversion evidence. Missing time columns and partial source coverage remain meaningful after either conversion, so a continuous mapped price path is not proof that every exposure bucket exists.