Gamma Exposure (GEX): How Dealer Hedging Shapes Every Move

What GEX Actually Measures

Gamma exposure is the aggregate dollar change in dealer delta per 1% move in the underlying, summed across the entire options chain. The sign matters more than the magnitude. Positive GEX = dealers are net long gamma; they sell into rallies and buy into dips, damping realized volatility. Negative GEX = dealers are net short gamma; they sell into dips and buy into rallies, amplifying moves in both directions. Same headline, same tape — but the path the market takes to price it in is completely different depending on which regime is in force.

What the GEX Summary Shows

The GEX Summary card reports four numbers per ticker: total GEX in dollars, the sign (highlighted in green or red), the zero-gamma flip level (the spot price at which net dealer gamma crosses zero), and the distance from spot to that flip. A distribution chart shows GEX by strike, so you can see *where* the gamma is concentrated — often clustered near round strikes or prior resistance/support levels that happen to match popular option lines.

Reading the Regime

Three rules-of-thumb cover most trade decisions. First, positive GEX + spot well above flip = low vol, mean-reverting tape, premium-selling environment. Second, negative GEX + spot well below flip = trending, volatile tape, premium-buying or long-vol exposure. Third, spot sitting near the flip level is the most dangerous configuration — small moves flip the regime, realized vol becomes discontinuous, and short-gamma structures (condors, strangles) can break in a single session. The zero-gamma level is not a price target but a volatility-regime boundary.

Where It Fits

GEX is the top of the options-context stack. Combine with Open Interest to locate the walls where gamma concentrates, and with Key Metrics for implied vs realized-vol context. On the macro side, the Universe GEX view shows regime-level dealer positioning across the S&P, which often moves before individual-name GEX does.

Open the GEX Summary card → /app/stocks/AAPL/sentiment