Positive gamma

Positive gamma is read directly off a ticker's net GEX profile: when the aggregate figure across the options chain is positive, dealers are net long gamma as a group. It's a snapshot of current options positioning, not a forecast, built from every strike and expiry currently open rather than any single contract. The strength of the effect scales with the size of the positive reading. A modestly positive GEX profile produces a mild stabilizing pull; a large one produces a much stronger one.

In a positive gamma regime, dealer hedging becomes a source of resistance against momentum. As price rises toward a level with heavy positive gamma, dealers who are long that gamma sell the underlying to stay hedged, which caps the rally. As price falls, the same mechanism runs in reverse and buys the dip. The practical read is that positive gamma tends to favor range-bound, mean-reverting price action over trending moves, part of why realized volatility often runs lower during stretches when a name or index is sitting well above its zero-gamma flip line.

Positive gamma describes hedging pressure, not a guarantee against a big move. A strong enough catalyst, an earnings surprise, a macro shock, unexpected news, can overwhelm the dampening effect entirely, and the regime itself isn't fixed. It shifts as the options chain rolls, new positions open, and existing ones expire, so a name sitting comfortably in positive gamma today can cross into negative gamma within days without any change in the stock's own fundamentals. It also says nothing about direction: positive gamma dampens moves in either direction equally, and isn't a bullish or bearish signal on its own.

Picture SPY trading at $747.03 with net GEX solidly positive and the zero-gamma flip line sitting near $728, comfortably below spot. A move up toward $755 on a strong jobs report would likely draw dealer selling that slows the rally, and a pullback toward $740 would likely draw dealer buying that cushions the drop, both consistent with the positive-gamma hedging pattern. If a surprise headline instead knocked SPY straight down through $728, the dampening effect would fade fast as the market crossed into the negative-gamma regime on the other side of that line.