Net GEX: How to Read the Bar Chart

Published by Cristian Ibáñez

Net GEX is the bar chart that sums call and put gamma exposure at each strike. It shows, point by point across the price axis, where the options market's hedging pressure concentrates. A bar above zero marks stabilizing pressure. A bar below zero marks pressure that amplifies the move. The crossing point between the two zones is the Flip, and the largest bars on each side mark the Call Wall and the Put Wall.

This article teaches you to read that chart end to end: what each bar measures, how the number behind it is calculated, and how to use the read in your daily trading routine.

What Net GEX Is

Net GEX is the strike-by-strike version of Gamma Exposure (GEX). While GEX describes the market's hedging pressure as a concept, Net GEX is the data already spread across the price axis: one bar for every strike with open options.

Each bar represents how much hedging the open positions at that specific strike generate, and which direction that hedging pushes on the price of the underlying. Adding up every bar on the chart gets you the market's total Net GEX, the number that determines whether you're in a Long Gamma Regime or a Short Gamma Regime.

It's the central piece of the GEX map. Every other level, the Flip, the Call Wall, the Put Wall, and the Long-wall, is read directly on this same chart.

How Net GEX Is Calculated

The calculation starts at a single strike. That strike has open call contracts and open put contracts, each with its own open interest and its own Gamma. According to CME Group (2026), Gamma measures how fast an option's Delta changes as the underlying's price moves. Investopedia describes it the same way: the sensitivity of Delta to movements in the underlying.

To reach the Net GEX of a strike, the calculation adds two components:

1. The call GEX at that strike. Obtained by multiplying call open interest by its Gamma and by the standard contract multiplier. Contributes a positive sign.
2. The put GEX at that strike. Calculated the same way, using put open interest and put Gamma. Contributes a negative sign.

The sum of those two components is the height and the sign of the bar you see at that point on the price axis. Repeat that calculation strike by strike across the entire options chain, then sum the result of every strike together. That's the market's total Net GEX, the single number that summarizes the day's full hedging pressure.

Key idea: you don't need to run this calculation yourself. GammaContext updates it in real time for you, for any asset with a liquid options market that you follow on the platform. What you need is to know how to read the result.

Figure 1. The Net GEX chart: each bar represents a strike, and its height and sign summarize the hedging pressure at that price point.

How to Read the Bar Chart

The Net GEX chart has two axes. The horizontal axis is the underlying's price, ordered from lowest to highest strike. The vertical axis is the magnitude of Net GEX at that strike: positive going up, negative going down.

Each bar corresponds to a strike. The taller the bar, the heavier the concentration of hedging at that price point. A small bar means little structural pressure at that level. A large bar means that strike concentrates a meaningful share of the market's total hedging.

The sign of the bar tells you the type of pressure:

• Positive bar: hedging that stabilizes price dominates. That strike falls in Long Gamma Regime territory.
• Negative bar: hedging that amplifies the price move dominates. That strike falls in Short Gamma Regime territory.

According to a Cboe analysis of the market impact of same-day expiration (0DTE) index options, the sign of market makers' aggregate gamma determines whether their hedging dampens or reinforces the underlying's move. That's exactly what you're seeing when you compare the positive side of the chart with the negative side.

Reading the full chart, left to right, gives you a snapshot of how hedging pressure is distributed across the entire price range the underlying trades in that day.

How to Spot the Flip on the Chart

The Flip is the exact point where the Net GEX chart crosses zero. On either side of that point, the bars change sign: they go from positive to negative, or from negative to positive.

To find it, follow the price axis to the point where the bars stop being positive and start being negative, or the other way around. That crossing marks the boundary between the Long Gamma Regime and the Short Gamma Regime.

Figure 2. The Flip is the zero crossing: the exact point where the Net GEX bars change sign.

Price relative to the Flip tells you which regime the market sits in right now. Price above the Flip, with total Net GEX positive, is the Long Gamma Regime. Price below the Flip, with total Net GEX negative, is the Short Gamma Regime. This guide dedicates a full article to this level: Flip: The Level Where the Market Regime Changes.

The Call Wall and Put Wall on the Net GEX Chart

Inside that same bar chart sit the Call Wall and the Put Wall, the two largest structural levels on the map.

The Call Wall is the tallest positive bar on the chart, usually located above the current price. It concentrates the heaviest selling hedging pressure and acts as structural resistance.

The Put Wall is the deepest negative bar on the chart, usually located below the current price. It concentrates the heaviest buying hedging pressure and acts as structural support.

Figure 3. The Call Wall, the tallest positive bar, and the Put Wall, the deepest negative bar, on the same Net GEX chart.

Between the Call Wall and the Put Wall sits the range where price tends to move while the market stays in the same regime. The article dedicated to these two levels goes deeper into how they form and how to use them: Call Wall and Put Wall: The Structural Levels of the GEX Map.

How to Use Net GEX in Your Daily Trading

The Net GEX chart doesn't replace your technical analysis. It adds to it as a layer of context on where the options market concentrates its hedging.

Here are the most direct reads you can pull from the chart every day:

1. Locate the Flip first. It tells you whether current price sits in a Long Gamma Regime or a Short Gamma Regime, and that changes which setups make the most sense that day. For the full regime breakdown, check Long Gamma vs. Short Gamma Regime: The Two Faces of Gamma.
2. Mark the Call Wall and Put Wall as reaction zones. They're the range extremes where the odds of a price reaction rise.
3. Watch the relative size of the bars. Large, concentrated bars point to levels with more structural strength. Small, scattered bars point to a map with less definition that day.
4. Check the chart at the open and again at midday. The strikes with the heaviest Net GEX tend to stay stable through the day, but it's worth confirming them at those two key moments.

Example: with price trading above the Flip and approaching the Call Wall, the Net GEX chart favors reading that approach as a reaction zone before looking for continuation. The same price crossing below the Flip shifts the read toward a trending context. Illustrative figures and scenario.

GammaContext calculates and updates this chart for you, for any asset with a liquid options market that you follow on the platform. Your job is to read it, not to build it.

Frequently Asked Questions About Net GEX

What does a positive bar mean on the Net GEX chart? It means hedging that stabilizes price dominates at that strike. That bar contributes to the Long Gamma Regime.

What does a negative bar mean on the Net GEX chart? It means hedging that amplifies the price move dominates at that strike. That bar contributes to the Short Gamma Regime.

Is the market's total Net GEX the same as the sum of all the bars? Yes. Total Net GEX is the algebraic sum of every bar on the chart, positive and negative. That number defines the market's overall regime.

How often does the Net GEX chart change during the day? It changes continuously, as positions open and close in the options market. The strikes with the heaviest concentration, like the Call Wall and Put Wall, tend to move less than secondary strikes.

Does the Flip always sit at the current price? Not necessarily. The Flip can sit above, below, or very close to the current price. Its location relative to price is exactly what defines the active regime.

Do I need to trade options to read the Net GEX chart? No. The chart describes the underlying. You can use it while trading futures, stocks, or any other instrument on that same underlying.

Does the Net GEX chart work the same for any asset? Yes. The mechanism is the same for any asset with a liquid options market, whether it's an index, a future, or a stock.

Next Step in the GEX Guide

You now know how to read the Net GEX chart end to end: what each bar measures, how it's calculated, and how to spot the Flip, the Call Wall, and the Put Wall on it. The natural next step is going deeper into the level that marks the regime change.

Continue with: Flip: The Level Where the Market Regime Changes.

You might also like:

• What Is Gamma Exposure (GEX): The Foundational Guide
• Call Wall and Put Wall: The Structural Levels of the GEX Map
• Long Gamma vs. Short Gamma Regime: The Two Faces of Gamma
• GEX Terminology: The GammaContext Glossary

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About Cristian Ibáñez: Cristian is CEO & Founder of SiomTrading, Lauz and GammaContext. He's an intraday algorithmic trader in Chicago futures. He has spent years building trading tools and gamma exposure systems. He leads the SiomTrading community, with more than 1,900 traders trained. Connect with Cristian on LinkedIn.