Gamma exposure (GEX) — the dealer-gamma framework that drives every modern equity move
Gamma exposure is the most misunderstood concept in modern options markets. This page explains what GEX really is, how dealer gamma actually works, why spot gamma matters, and how to trade gamma flips and pinning zones — written by a 17-year derivatives desk veteran.
Everything you need to understand gamma exposure
What is gamma exposure?
Gamma exposure (GEX) measures the aggregate gamma position of options dealers. Positive GEX dampens moves (dealers sell rips, buy dips); negative GEX amplifies them (dealers chase the move). It is the single most important hidden flow in equity markets.
How dealer gamma works
When you buy an option, a dealer sells it and must delta-hedge. As spot moves, their delta changes (= gamma), forcing them to rebuy or resell stock. The net direction of this hedging flow IS dealer gamma — the engine behind pinning, gamma flips and squeezes.
Spot gamma vs total gamma
Spot gamma is the gamma evaluated at current spot. Total gamma sums all strikes. The famous "gamma flip" level is where total spot gamma crosses zero — above it, markets mean-revert; below it, they trend violently.
Options gamma in the Greeks
Gamma is the second derivative of option price with respect to spot — the rate of change of delta. It peaks ATM and decays for deep ITM / OTM options. Short-dated options have the highest gamma; this is why 0DTE drives modern intraday moves.
How to trade around GEX
In high positive GEX regimes: fade extremes, sell premium with discipline. In negative GEX: respect breakouts, buy convexity, expect violent end-of-day moves. The regime matters more than the trade idea.
GEX in CrossVol Terminal
Live dealer GEX for SPX, NDX, RUT and single names. By strike, by expiry, with the gamma-flip level updated in real-time as flow comes in. The same calculation desks use, made available to serious independent traders.
Why our GEX work is different
Most "GEX" you see on social media is back-of-envelope: open-interest x gamma, assumed dealer-short, summed crudely. Our calculation uses the proper dealer-positioning assumption per expiry bucket, accounts for vanna and charm flow, and integrates real-time option-volume flow — the way a desk would actually do it. Verified against 17 years of intraday vol-desk experience.
View live GEX in the Terminal →
The book on gamma exposure
Beyond Gamma Exposure
The complete framework for reading dealer gamma, vol surfaces, dispersion and cross-asset flow — 320 pages, the textbook on this topic.
View on Amazon →Frequently asked questions about gamma exposure
What is gamma exposure (GEX) in simple terms?
Gamma exposure measures how much stock options dealers must buy or sell to stay delta-hedged as the market moves. When dealers are net long gamma, they buy dips and sell rallies — dampening moves. When net short gamma, they chase moves — amplifying them.
What is dealer gamma?
Dealer gamma is the aggregate gamma position of market-making options dealers. It is the inverse of what end-investors hold: when retail buys lots of calls, dealers are short gamma; when retail sells puts, dealers can be long gamma.
What is the gamma flip?
The gamma flip is the spot level at which net dealer gamma crosses from positive to negative (or vice versa). Above the flip, dealers stabilise the market. Below it, they destabilise it. This level is one of the most important intraday signals in modern equity markets.
How is spot gamma different from total gamma?
Spot gamma is the gamma value at the current spot price. Total gamma sums gamma contributions across all strikes and expiries. Spot gamma tells you about the immediate hedging flow; total gamma tells you about the structural regime.
Is GEX a reliable trading signal?
GEX is a regime signal, not a price-prediction signal. It tells you what kind of behaviour to expect (mean-reversion vs trend) but does not by itself tell you direction. Combined with positioning, flow and macro, it is one of the most powerful frameworks in modern vol trading.
Where can I see live gamma exposure?
CrossVol Terminal provides live dealer GEX for SPX, NDX, RUT and major single names, by strike and by expiry, with the gamma-flip level updated in real-time.
How do I learn to trade gamma exposure?
Read the book "Beyond Gamma Exposure" for the framework, then join CrossVol Academy to see GEX-based trades being entered and exited in near real-time on a live book.