SPX GEX into the close, sitting on a $4B gamma wall at 6600

GEX: When you buy an option, a market maker (dealer) takes the other side. To stay hedged, they buy or sell the underlying based on their delta exposure. As price moves, that delta changes, and they have to keep rebalancing. That rebalancing is the gamma effect on price. GEX measures the aggregate dollar value of that hedging pressure at each strike.

On today's data / 3:30pm EST:

The big wall: $6,600 strike (~$4B positive GEX) This is the dominant feature. Dealers are long gamma here, meaning they buy dips and sell rips around this level. That creates a gravitational pull, spot tends to get "pinned" near large positive GEX strikes, especially into expiration.

Spot right now: 6601.20, sitting directly on it.

Gamma Flip at $6,520 Below this line, net GEX turns negative. Dealers flip from stabilizers to amplifiers, they'd be selling into drops and buying into rips, which accelerates moves. This is your key "things get chaotic" threshold to watch.

Red bars (negative GEX) below $6,520 Small but present. Confirms the flip zone is real, not just a line on a chart.

I think, with this much positive gamma concentrated at 6600 and expiration pressure building, the path of least resistance is a close near 6600.