Glossary · Options
Gamma exposure (GEX) is the aggregate gamma position of options dealers, projected across strikes. Because dealers hedge their gamma by trading the underlying, GEX predicts where dealers will buy or sell stock or futures as price moves — and which strikes will act as price magnets (gamma walls) or repellents (gamma flip).
GEX is the dealer-positioning model that explains why SPX gets pinned to round numbers on monthly options expiration, why 0DTE moves can accelerate violently in one direction, and why certain strikes feel “sticky” on the chart even without obvious technical reasons. It is one of the most widely-tracked retail options analytics in 2026.
“GEX estimates aggregate dealer gamma by strike, marking where hedging flows tend to concentrate.”
Options dealers (market makers) are net short gamma in normal markets — they sell more options to retail and institutions than they buy. Short gamma means: as the underlying moves, the dealer’s delta drifts away from flat, forcing them to hedge by trading the underlying in the same direction as the move (selling into dips, buying into rallies). That hedging flow is mechanical, predictable, and large enough to move price.
The flip side: when dealers are net long gamma (heavy call demand from institutions, for example), their hedging is counter-trend — they buy into rallies and sell into dips, dampening volatility.
GEX projects this aggregate dealer position across the strike chain, so traders can see ahead of time: at this price, dealers are forced to sell; at that price, dealers are forced to buy. The map predicts the counterforce.
A complete GEX model surfaces nine distinct level types. Each answers a different question about dealer positioning:
Call wall
Strike with the largest positive call gamma; dealers most motivated to sell the underlying as price approaches. Acts as resistance.
Put wall
Strike with the largest negative put gamma; dealers most motivated to buy the underlying. Acts as support.
Gamma flip
Price level where aggregate dealer gamma transitions from positive (vol-dampening) to negative (vol-amplifying). The most important regime line.
Max pain
The strike where the maximum dollar amount of options expires worthless. Often a magnet into expiration.
Expected move
The implied 1-standard-deviation move priced by the at-the-money straddle. Frames how big a 'normal' move looks.
High-gamma zones
Bands of strikes with concentrated dealer gamma. Price tends to hover or pin in these zones.
Vanna
Sensitivity of delta to changes in implied volatility. Drives the relationship between vol and dealer hedging flow.
Charm
Sensitivity of delta to time decay. Drives end-of-day and end-of-week hedging flow as theta accelerates.
0DTE percentage
Share of total options open interest expiring same-day. As 0DTE rises (now ~50% of SPX volume), gamma flips faster and intraday moves get more violent.
Sharpnel Trading — $125/mo
GEX with all nine level types drawn on the same chart as the DOM ladder, the footprint, and the tape — dealer levels on the order flow you’re already reading. Black-Scholes on live implied volatility. Bundled with the full options workspace (OMON heatmap, HVOL, IV skew, multi-leg P/L, earnings IV crush, unusual flow tape) in one subscription.
Dealer-positioning specialists — $50-250/mo
Real-time GEX on the top tier (around $250/mo); lower tiers run on delayed data. Web-based dashboards with strong educational content. Specialist tools — no DOM, footprint, or orderflow surfaces.
Free GEX feeds (limited)
Several social accounts and options-flow blogs post daily GEX levels for SPX and a few mega-caps. Useful for context; not real-time.
Most general-purpose charting tools
No native GEX overlays. Some users build their own GEX visualizations via custom indicators, but the math is non-trivial and the live options-chain data isn’t always accessible.
Gamma exposure is the aggregate gamma position of options dealers, projected across strikes. Because dealers hedge their gamma by trading the underlying, GEX predicts where dealers will buy or sell stock or futures as price moves — and which strikes will act as price magnets (gamma walls) or repellents (gamma flip). It's the dealer-positioning model that explains why SPX gets pinned to round numbers on OpEx and why 0DTE moves can accelerate violently in one direction.
The gamma flip is the price level at which aggregate dealer gamma transitions from positive to negative (or vice versa). Above the flip, dealers are net long gamma — they sell into rallies and buy into dips, dampening volatility. Below the flip, dealers are net short gamma — they sell into dips and buy into rallies, amplifying moves. Pros watch the flip as the most important regime line on the SPX intraday chart.
A call wall is a strike with the largest aggregate positive gamma exposure on the call side — dealers are most long-gamma there, so they're motivated to sell the underlying as price approaches it, creating resistance. A put wall is the symmetric strike on the put side — dealers most short-gamma there, motivated to buy the underlying, creating support. Both act as price magnets that traders mark on their charts.
GEX is calculated using Black-Scholes gamma per option contract, multiplied by open interest at each strike, summed across all expirations, and adjusted for dealer-positioning assumptions (typically: dealers are short calls and long puts net of customer flow). The math itself is well-defined; the assumptions about dealer positioning are where different GEX providers diverge. Sharpnel and other GEX tools all use Black-Scholes on live IV but differ in how they model the customer/dealer split.
Dedicated dealer-positioning services charge roughly $250/mo for real-time GEX alone, as a standalone dashboard with no order flow. Sharpnel Trading is different: it draws GEX (nine level types — call wall, put wall, gamma flip, max pain, expected move, high-gamma zones, vanna, charm, 0DTE percentage) on the same chart as the DOM ladder, the footprint, and the tape, at $125/mo — so dealer levels sit on the order flow you're already reading. Several free options-flow blogs and social accounts post daily GEX levels for SPX and a few mega-caps but don't update in real time. Most general-purpose charting tools have no native GEX overlays.
GEX overlay on a live SPX chart with all nine level types — call wall, put wall, gamma flip, max pain, expected move, high-gamma zones, vanna, charm, 0DTE percentage — lives inside the Sharpnel terminal at $125/mo Pro. Free Explorer tier shows GEX on SPY/QQQ.
Today’s free read
The ES/NQ dealer-gamma map — the walls, the flip point, the regime — free every morning, yesterday’s levels graded in the open.
