Exposure heatmaps by strike and expiration

This page of GEXStream shows the Heatmaps view: a strike-by-expiration grid of gamma exposure (GEX), volume-weighted gamma exposure (vGEX), delta exposure (DEX), vanna exposure (VEX), charm exposure (CEX), open interest (OI) and net implied volatility (IV) for one ticker, drawn as a 2D table or a 3D surface. The dashboard chart sums each strike over one expiration, or over the date range you pick; the heatmap lays the next twelve expirations side by side, so you can see which expiration carries a level rather than only where it sits on the strike ladder.

GEXStream dashboard exposure chart on the vGEX chip: per-strike bars, green positive and red negative, with the spot line and the family chip row GEX, vGEX, DEX, VEX, CEX and OI in the top right — The dashboard exposure chart with its family chip row (GEX, vGEX, DEX, VEX, CEX, OI). The Heatmaps page offers the same six families, each strike split across the next twelve expirations instead of summed into one bar.

What it shows

Each grid has one row per listed strike, highest at the top, and one column per expiration, nearest first. On a desktop the window is 49 strikes (24 either side of spot) across the next 12 expirations; on phones and tablets it is 25 strikes across 8 expirations. The row nearest spot is washed gold, but only while spot actually sits inside the window.

Each cell is one strike on one expiration. A GEX cell is call gamma times call open interest minus put gamma times put open interest, each times 100; a vGEX cell replaces open interest with the session's traded volume. DEX, VEX and CEX cells add the call and put legs at their natural sign. OI cells are call plus put contracts, with no Greek weighting. Net IV cells are that strike's call IV minus its put IV, printed as signed vol points.

Two grids sit side by side (stacked on phones): the exposure family you select on the left, Net IV on the right. During regular hours (9:30 to 4:00 ET, Monday to Friday) the page refreshes every 5 seconds; outside them, every 60 seconds. Large values are shortened to K, M and B.

How to read it

Colour carries the sign and the weight. Positive cells are green, negative cells red, and the shade scales against the largest absolute value in the grid, so the deepest cell is the biggest level on screen, not an absolute threshold. The Net IV grid uses fixed rungs instead, deepening at 1, 3 and 5 vol points, so a given skew looks the same on every ticker.

Read a column top to bottom for one expiration's profile; read a row across for how a strike's weight is spread through time. A large GEX cell on the front expiration leaves the grid when that date rolls off; the same figure three columns out stays. The formulas and sign conventions live on the docs page: GEX and vGEX net calls against puts, while DEX, VEX and CEX sum call and put exposure at natural sign, so read their sign as the positioning of the options, not of a dealer's book. Open interest and IV have their own sections. Note that a Net IV cell is a single strike's call-minus-put spread, not the open-interest-weighted chain figure shown in the dashboard stats panel.

2D grid and 3D surface

A toggle switches both grids between the 2D table and a 3D surface. The surface puts strike on one axis and expiration on the other, with the cell value as height, on a red-white-green scale with contour lines. A gold line traces spot across every expiration, and hovering a point shows its strike, date and value. Only the Net IV surface centres white at zero, pinned at plus and minus 5 vol points.

The Heatmaps page opens in 2D and remembers your choice per browser. On the dashboard the panel opens in 3D, except in Safari and the iOS browsers, which get the 2D table because the 3D library repaints slowly there.

Panning the strike window

The up and down buttons move the window along the strike ladder by half a window per press, 12 strikes on a desktop and 6 on a phone, so half of the previous rows stay in view. The row count never changes and nothing is bucketed: the table is a viewport over listed strikes, and the buttons move it. A reset button appears while panned and returns the window to spot. The buttons dim once the listed strikes run out in that direction, the offset resets when you change ticker, and while a move is loading the grid dims rather than going blank.

The ticker field takes up to five characters and typing a full stop opens your watchlist.

The smaller heatmap in the dashboard

The dashboard's right panel carries the same two heatmaps for the ticker on screen, cut to 23 strikes across 6 expirations and pushed every 5 seconds. The left one follows the exposure chip you have selected on the main chart; the convexity ladder chip, which has no expiration axis, shows the vGEX heatmap there. In the 2D view the panel narrows to a dozen strikes around spot; the 3D surface draws the whole 23-strike window. Clicking either panel title opens the Heatmaps page on that ticker.

Which plans include it

Heatmaps are on every paid plan. Basic ($49.50 a month billed monthly) sees the GEX, OI and Net IV grids. Flow ($119.50) adds the vGEX family. Quant ($199.50) adds DEX, VEX and CEX. The server strips the families above your plan before it sends a frame, so what you see is exactly what your plan carries, and a ticker GEXStream does not cover answers "Ticker not covered.". The free trial runs with Quant access. Billing intervals are on the pricing page.

Real-time GEX dashboard: the per-strike exposure chart whose chips the heatmap families mirror.
IV term structure and IV surface: implied volatility across expirations by delta and by strike.
GEX history charts: how the exposure totals have moved over days and weeks.
All feature pages and the documentation.