Gamma Exposure (GEX)
Real-Time Dealer Positioning
Track dealer gamma exposure by strike for 6,000+ US equities and ETFs. See the gamma flip point, call walls, put walls, and volatility regime — the levels that drive intraday price action.
What is Gamma Exposure (GEX)?
Gamma exposure (GEX) quantifies the total gamma held by options market makers at each strike price. It tells you where dealers must hedge — and whether their hedging will dampen or amplify the next move in the underlying.
When options are traded, market makers take the other side. To stay delta-neutral, they continuously hedge by buying or selling the underlying stock. The rate at which they need to adjust depends on gamma — the second derivative of the option price with respect to the underlying.
GEX aggregates this gamma across all open strikes to reveal the net dealer positioning. It's the closest thing to a map of where the smart money is forced to trade.
"GEX is not a prediction — it's a positioning constraint. It tells you what dealers must do, not what they want to do."
How Dealer Gamma Positioning Works
Dealers (market makers) are structurally short options to retail and institutional buyers. Their gamma profile determines how they hedge:
- Long gamma (positive GEX): Dealers own gamma. When price rises, their delta increases and they sell shares. When price falls, they buy shares. This creates a mean-reverting environment — volatility is suppressed, and price tends to pin near high-GEX strikes.
- Short gamma (negative GEX): Dealers are short gamma. Price rises force them to buy (chasing), and price drops force them to sell (dumping). This creates a trending/volatile environment where moves accelerate.
This is why gamma exposure is one of the most powerful indicators in options analytics — it explains why certain price levels act as magnets while others trigger cascading moves.
GEX by Strike — Reading the Chart
A GEX chart displays gamma exposure at each strike price as a bar chart. Here's how to interpret it:
| Element | What It Means | Trading Implication |
|---|---|---|
| Tall positive bars | High dealer long gamma at this strike | Acts as support/resistance magnet |
| Negative bars | Dealers are short gamma here | Price accelerates through these zones |
| Call wall | Strike with highest positive GEX | Strong upside resistance — dealers sell rallies |
| Put wall | Strike with most negative GEX | Strong downside support — dealers buy dips |
| Gamma flip | Where net GEX crosses zero | Key regime change level — above = calm, below = volatile |
Try the free GEX tool to see these levels in real time for any ticker.
The Gamma Flip Point
The gamma flip is arguably the single most important level derived from GEX. It's the price where aggregate dealer gamma transitions from positive to negative.
- Price above gamma flip: Dealers are net long gamma. Expect lower volatility, tighter ranges, and mean-reversion toward high-GEX strikes. Good for selling premium.
- Price below gamma flip: Dealers are net short gamma. Expect higher volatility, trending moves, and gap risk. Dealers amplify directional moves. Good for buying options or momentum strategies.
Many professional traders watch the gamma flip as an intraday trigger — when price crosses below it, they expect volatility to expand; when it reclaims the flip, they expect the market to calm down.
Call Walls and Put Walls
Call walls and put walls are the strikes with the most concentrated gamma exposure. They act as natural support and resistance levels because of the enormous hedging flows they generate.
The call wall (highest positive GEX strike) is where dealers are most aggressively selling into rallies. Price often struggles to break through. The put wall (highest negative GEX strike) is where dealers aggressively buy dips. These levels shift daily as options are opened and closed.
FlashAlpha computes these levels in real time. See them on any stock GEX page or via the GEX API endpoint.
GEX vs DEX — Gamma Exposure vs Delta Exposure
GEX measures the rate of change of dealer hedging — it tells you about volatility. DEX (delta exposure) measures the directional bias of dealer hedging — it tells you about direction.
- GEX: "How much will dealers need to hedge per $1 move?" — Volatility signal
- DEX: "Are dealers net buyers or sellers of the underlying?" — Directional signal
Used together, GEX and DEX give a complete picture of options market structure. FlashAlpha provides both — along with VEX (vanna exposure) and CHEX (charm exposure) for second-order effects.
How Traders Use GEX Data
- Intraday support/resistance: Use the call wall and put wall as key levels for entries, exits, and stop-losses.
- Volatility regime detection: Check if price is above or below the gamma flip to determine whether to trade mean-reversion or momentum.
- 0DTE and weekly expiry: GEX concentrates heavily around near-term expirations. Understanding GEX is essential for 0DTE options trading.
- Event preparation: Before earnings or FOMC, check GEX to see where dealers are positioned. This reveals the "expected move" and where moves could accelerate.
- Hedging portfolio risk: Institutions use GEX to understand when their hedges may become less effective (short gamma regimes).
Free GEX Data — How to Get Started
FlashAlpha offers gamma exposure data through two channels:
1. Interactive GEX Tool (No signup needed to view)
The free GEX tool renders an interactive bar chart of gamma exposure by strike for any ticker. It shows the gamma flip, call wall, put wall, and net GEX. Just type a ticker and go.
2. GEX REST API
Programmatic access to GEX data via GET /v1/exposure/{ticker}/gex. Returns per-strike gamma in JSON format. The free Basic tier includes 5 requests per day — enough for research and prototyping.
curl -H "X-Api-Key: YOUR_KEY" \
https://lab.flashalpha.com/v1/exposure/SPY/gexGEX for Individual Stocks
Every stock on FlashAlpha has a dedicated GEX page with per-strike gamma exposure, gamma flip, and dealer positioning. Here are some of the most actively traded:
Don't see your ticker? FlashAlpha covers 6,000+ US equities and ETFs. Use the GEX tool to look up any symbol, or access programmatic data via the API.
Related Exposure Analytics
GEX is one of four exposure metrics FlashAlpha computes in real time:
Where dealers hedge. Volatility suppression vs amplification by strike.
Directional bias of dealer hedging. Net buying vs selling pressure.
Sensitivity of delta to IV changes. How vol moves affect dealer hedging.
Time decay of delta. How approaching expiry shifts dealer positioning.
More FlashAlpha Tools
- 3D Volatility Surface — Interactive implied volatility surface across strikes and expirations
- Options Greeks Calculator — Compute delta, gamma, theta, vega, rho for any option
- Implied Volatility Calculator — Back out IV from market prices
- Options Kelly Criterion Calculator — Optimal position sizing for options trades
Start Using GEX Data — Free
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