An estimate of the net option gamma that dealers must hedge, built by strike from open interest. It tells you how much stock dealers have to buy or sell as price moves to stay delta-neutral — and therefore whether their hedging will dampen or amplify the move.

The price where cumulative net dealer gamma crosses zero — the boundary between the long-gamma regime (above) and the short-gamma regime (below). Above it hedging stabilizes; below it hedging amplifies.

Long gamma: dealers sell rallies and buy dips to stay hedged — counter-trend, stabilizing, range-compressing. Short gamma: dealers buy rallies and sell dips — pro-trend, amplifying, range-expanding. Same desk, opposite flow, decided by the sign of net gamma.

No. Net long gamma means stabilizing, not up. A long-gamma market can drift lower quietly; a short-gamma market can rip higher. GEX tells you the character of the tape — calm or violent, mean-reverting or trending — not the direction.

Market-makers warehouse the options the public trades and don't want directional risk, so they offset their delta with the underlying. Gamma means that delta keeps changing as price moves, so they must keep re-hedging — and that re-hedging is the flow GEX estimates.

It's the standard sign convention: dealers are assumed long call gamma and short put gamma — the mirror of customers who buy puts for protection and sell calls for yield. So call open interest adds positive GEX, put open interest negative. It's a well-used assumption, not a law.

In a long-gamma regime, dealer hedging pulls price back toward heavy-gamma strikes — selling above them, buying below them. Near expiration that magnetism can "pin" the close to a big strike. It's a tendency, strongest when gamma is concentrated and the market is calm.

No — it's an estimate that moves with open interest, spot, and the implied vols used, and it can shift intraday. Read it as a regime boundary and a zone, not a hard trigger. Its value is telling you which side you're on, not pinpointing a price to the penny.

GEX is a heuristic, not a flow model. It assumes the sign convention, uses listed open interest (which lags), can't see OTC or true dealer inventory, and depends on the implied vols feeding the gammas. Use it for regime and concentration, not precise predictions.

ETFs on the ETF Analytics tier; any optionable single stock on ETF + Equities. The full GEX-by-strike data is available as a CSV export on the Everything tier.

Dealer gamma is the positioning lens — how hedging will push price. The vol tools are the price-of-vol lens: Term Structure (across time), Skew (across strikes), Cones (versus realized history). Together they tell you what vol costs and how its hedging is likely to move the tape.