What dealers hedge

Dealers don't want direction.

Market makers take the other side of most customer options trades. Holding those options exposes them to moves in the underlying. They hedge that exposure by trading the underlying stock, adjusting continuously as price moves.

Their hedging changes the tape.

When dealers are long gamma, price rising makes them sell stock to stay neutral. Price falling makes them buy. That dampens moves in both directions. Total GEX is a model estimate of which side of that equation the market is in right now.

Dealer exposure at each strike.

The tall bars mark where dealer hedging is most intense. The flip level shows where the regime changes from dampening to amplifying. This snapshot updates throughout the day as new options flow prints.

This one is an animated diagram in the app. See it in Vero.