Gamma Exposure (GEX)

What Is Gamma Exposure?

Gamma exposure (GEX) measures how much buying or selling pressure market makers create as they delta-hedge their options positions when price changes. It’s calculated by summing the gamma of all outstanding options contracts, weighted by open interest and contract size.

Track real-time GEX levels across all major indices with Options Flow’s GEX Tools.

When market makers sell options (most common), they must hedge by trading the underlying. If price rises, they sell shares to stay delta-neutral. If price falls, they buy shares. This creates a self-stabilizing feedback loop — large positive GEX suppresses volatility and pins price near a range.

Why It Matters for Options Traders

GEX explains price behavior that pure technical analysis cannot. A stock pinned in a tight range before expiration often reflects positive GEX at work: dealers continuously buying dips and selling rallies as they hedge.

Negative GEX flips this. When dealers are long options (bought from sellers), they hedge in the same direction as price movement — buying when it rises, selling when it falls. This amplifies moves rather than dampening them, contributing to volatile, trending conditions. The 2020-2021 meme stock events showed negative GEX dynamics at extremes.

Traders use GEX to identify pinning levels near expiration, understand why certain strikes act as support or resistance, and anticipate whether conditions favor mean-reversion or momentum strategies.

Key Levels and Signals

• Positive GEX (dealers short gamma): Price tends to pin, low realized volatility
• Negative GEX (dealers long gamma): Price tends to trend, volatility expands
• GEX flip level: Price where aggregate gamma transitions from positive to negative — inflection point for volatility regimes
• Strike-level GEX: Where largest dealer hedging pressure concentrates; acts as magnet for price near expiration