Understanding Gamma Exposure (GEX) in Options

Educational Guide · Updated March 2026

Gamma Exposure (GEX) measures the total gamma that options market makers hold at each strike price. It reveals where dealers need to hedge, creating predictable flows that move the underlying asset's price.

What Is Gamma?

Gamma measures how much an option's delta changes for a $1 move in the underlying. When market makers sell options, they take on gamma exposure. To stay delta-neutral, they must continuously buy or sell shares — and these hedging flows directly impact stock prices.

Positive vs Negative GEX

• Positive GEX — Dealers are long gamma. They sell into rallies and buy dips, suppressing volatility. Markets tend to be range-bound and mean-reverting.
• Negative GEX — Dealers are short gamma. They must buy into rallies and sell into dips, amplifying moves. Markets become volatile and trend-following.

Key GEX Levels

• GEX Flip — The price level where gamma shifts from positive to negative
• Max Pain — Strike with highest open interest, where options expire worthless
• Call Wall — Highest positive gamma from calls, acts as resistance
• Put Wall — Highest negative gamma from puts, acts as support

Using GEX in Trading

Tracking GEX helps traders understand when to expect mean-reversion vs breakout conditions. In positive GEX environments, selling premium and fading moves tends to work. In negative GEX, trend-following and breakout strategies have an edge.