Context: use positioning to support the chart.

Know which options you are looking at.

Direction, Location and Timing describe the price picture. Context adds the options map around it. Start with the snapshot date, selected expiration and strike filter before interpreting a large number or a dark cell.

In the saved example below, the data snapshot is October 22, 2026. The selected expiration is October 23. That selection drives the headline metrics and strike chart, while the heatmap compares October 23, 26 and 28 side by side. The three columns are separate expiration books.

Keep those scopes distinct. A total for one expiration is not the total for every displayed date. Likewise, a later refresh can change the map without changing the way the calculation works. Always carry the date and selection into your notes.

Read the measures before the colors.

Gamma describes how an option’s delta is expected to change as the underlying price moves. The Desk combines provider gamma, open interest, a contract multiplier and the underlying reference to express GEX in dollars per 1% underlying move.

Total Net GEX: The signed sum for the selected options book. Calls contribute positively and puts negatively in this model.
Positive / negative GEX walls: The strikes with the largest positive and most negative net GEX within the selected scope.
Call / put walls: The largest call and put GEX concentrations, measured separately before the two sides offset.
Gross gamma: The combined call and put magnitudes without cancellation. A small net total can still hide large opposing sides.

The sign convention is an assumption. A long call and a long put both have positive option gamma. Assigning calls a positive contribution and puts a negative contribution in this display is a modeling choice; it does not reveal who holds either side.

The gamma regime names the sign of Total Net GEX. Green and red describe positive and negative modeled exposure. Neither color is a buy or sell instruction, and a dollar-GEX figure is not premium spent or cash waiting to enter the stock.

Gamma background: The Options Industry Council’s gamma guide ↗

One strike. Read every expiration.Illustrations · invented GEX values

Follow the $100 row across both maps. Each column is a different expiration from one hypothetical snapshot.

A clear concentration

The same positive wall across expirations

Net GEX · $M per 1% underlying move
Strike	Exp. 1+7.6Total	Exp. 2+6.3Total	Exp. 3+5.2Total
$110	+0.5	+0.4	+0.3
$105	+1.0	+1.2	+0.8
$100	+8.0 , positive GEX wall	+6.0 , positive GEX wall	+5.0 , positive GEX wall
$95	−1.5	−1.0	−0.7
$90	−0.4	−0.3	−0.2

Totals sum the five shown strikes. Outlines mark each column’s positive GEX wall.

The $100 row is the largest positive net GEX concentration in every column. It gives you a consistent reference to bring back to the price chart.

The read: One positive concentration repeats. Price still has to respond.

A mixed map

The positive wall shifts with expiration

Net GEX · $M per 1% underlying move
Strike	Exp. 1+2.0Total	Exp. 2−0.4Total	Exp. 3+0.5Total
$110	+0.5	−0.6	+1.0
$105	+1.5	−1.3	+6.0 , positive GEX wall
$100	+8.0 , positive GEX wall	−7.0	+1.0
$95	−6.0	+6.0 , positive GEX wall	−5.0
$90	−2.0	+2.5	−2.5

Totals sum the five shown strikes. Outlines mark each column’s positive GEX wall.

The $100 row changes sign across expirations. Positive walls move from $100 to $95 to $105, while opposing strike exposures leave small column totals.

The read: Read each expiration separately. Don’t force one level.

−$8M+$8MOne color scale for both maps

These are separate invented books, not a before-and-after sequence. Green and red show the model’s sign, not a price forecast. A wall is a concentration to investigate—not guaranteed support, resistance or observed dealer inventory.

Follow the levels in the saved NVDA book.

This is the options snapshot paired with the earlier lessons. Read the selected date first, then the highlighted strikes and the three heatmap columns.

NVDA · Check the scope. Then follow the wall.Saved session · October 22, 2026

Open annotated chart ↗

1
Confirm the selected expiration.
October 23 drives the headline −$46.63M net GEX. Negative gamma here means a negative modeled total; it is not a bearish price prediction.
2
Locate the concentrations.
The positive GEX and call walls share $220. The negative GEX and put walls share $210. They are separate measures that happen to align here.
3
Compare dates consistently.
Each heatmap column represents its own expiration. Follow a strike across columns and use the shared color scale to compare sign and size.

Historical provider-data caveat: this saved options book uses $212.86 while the chart closes at $212.21. The worked example documents the end-of-day reference issue affecting IV and Greeks; these figures illustrate how to read the display and are not independently verified synchronized closing inputs.

The read: Use $210 and $220 as references to investigate alongside price. Neither a wall nor the regime proves a future bounce, direction or actual dealer inventory.

Selected October 23 book: −$46.63M. The model’s total is negative. It does not establish that NVDA will fall.
Positive GEX and call walls: $220. The two measures share a strike here. A call wall and a net-positive wall can sit at different strikes in another snapshot.
Negative GEX and put walls: $210. These also coincide. Treat $210 as a reference to investigate with price, not a floor the stock must hold.

Trace one row across the heatmap.

At $220, the displayed net GEX is approximately +$39.3M for October 23, +$451K for October 26 and +$571K for October 28. They are all positive, but their sizes differ. The shared color scale helps show that difference.

A green $220 cell can sit inside an expiration with a negative total. The cell describes one strike; the header sums the expiration. Read both before calling the whole column positive or negative.

“The selected October 23 model is net negative, with highlighted concentrations at $210 and $220. Those levels add references to the chart; they do not decide its next move.”

The saved options reference is $212.86; the daily chart closes at $212.21. The historical data caveat above is part of the example. These figures teach the display and should not be treated as independently verified, synchronized closing inputs.

Keep open interest and flow separate.

Open interest counts outstanding option contracts. Volume counts contracts traded during a session. A trade can open a position, close one or transfer it, so volume does not translate directly into an equal increase in open interest.

Definitions: OIC on open interest and volume ↗

A positioning snapshot

This GEX view combines the captured Greeks and open interest. It shows modeled concentrations at that snapshot. It does not show a time-and-sales record of new option purchases.

A flow observation

A separate trade feed can add execution information. Before assigning intent, ask whether you know the side, opening or closing status, and whether the trade belongs to a larger strategy. Record unknowns as unknowns.

A large call trade is not enough, by itself, to label the buyer bullish or the dealer short gamma. Cboe’s SPX research illustrates why transaction-side and opening/closing information matter when measuring actual market-maker positions. This NVDA screenshot does not contain that information.

Positioning context: Cboe’s explanation of net positioning ↗

Bring the map back to price.

Return to the observations from the first three lessons: NVDA’s daily close is below the cloud, inside the displayed value area and below POC, while Pulse is below its centerline and signal. The options map adds nearby reference strikes; it does not repair that price or momentum picture.

A wall is not an order waiting to execute.

The label identifies a concentration in the model. It does not prove support, resistance, a destination or the size of a future hedge.

Negative gamma is not a bearish forecast.

A negative modeled total does not tell you the direction of the next price move. Keep the regime description separate from your reading of trend.

A complete display can still have imperfect inputs.

Check the snapshot time, underlying reference and any uncertainty or unavailable labels. A saved fallback remains dated data. Filling a screen does not make its inputs fresh or synchronized.

If context conflicts with your chart read—or the inputs are too uncertain to interpret—write that down. Waiting for clearer evidence is a valid outcome of the framework.

Try the read yourself.

The October 23 expiration has a negative total, but its $220 cell is positive. Is that a contradiction? Does the $210 put wall guarantee support?

Show the reasoning

No to both. A positive cell describes one strike. Other strikes can outweigh it and leave the expiration total negative. The put wall identifies a modeled concentration; it does not guarantee how price responds there.

Now describe the snapshot in one sentence. Include the selected expiration, the sign of its total and the two reference strikes—without predicting a bounce or a decline.