The short version of the GexHunters Field Guide: where each line comes from and what price tends to do when it gets there. Nothing here is a signal on its own — the levels tell you where the hedging is, you decide the trade.
Every option has a delta, and the dealers on the other side of most option trades hedge that delta by holding the opposite position in the underlying. Gamma is how fast that delta changes as price moves, so near a strike with a lot of open interest the dealers' hedge is constantly out of date and has to be adjusted — real buying and selling, in size. Gamma exposure (GEX) adds that up for every strike:
Calls count as positive dealer gamma, puts as negative. The sign is the whole game.
Dealers are net long gamma. They sell into rallies and buy into dips, so moves get dampened, ranges hold and price grinds or pins. Mean-reversion setups work.
Dealers are net short gamma. They buy strength and sell weakness, so moves get amplified, ranges break and follow-through is real. Trend and squeeze days.
Built from the nearest expiration's option chain, re-baked at every update.
The strike above price carrying the heaviest call gamma — the biggest pile of dealer long-gamma overhead. Dealers sell into it to stay hedged, so rallies stall, chop or roll over here far more often than not. Resistance first, magnet second. A clean break and hold above it, especially when the wall then moves up at the next update, means the book has repositioned.
The strike below price with the heaviest put gamma — the biggest shelf of protection in the book. Sell-offs tend to slow and bounce here while price is above the Gamma Flip. Below the flip that cushion is gone: a break can accelerate instead of bounce. Put Wall above the flip is support; Put Wall below the flip is a trapdoor.
The price where net dealer gamma crosses zero. Crossing below it usually means volatility expands; crossing back above it usually means it contracts. Price hovers and whipsaws right at the flip because the hedging flows cancel out there. This is a regime switch, not a level to fade.
The strike where the total value of all open options at expiration would be smallest. Gravity, not a wall: its pull is strongest in the last couple of hours before the nearest expiration, when pinning flows drag price toward it. Earlier in the session it is a bias, not a target.
The same three run again on the same nearest-expiration chain, held to a tighter 3% leash. The nearest pin and bounce points: zero-day gamma is the sharpest gamma there is, so price often reacts hard here on a short timeframe, and the level is gone by the next update. When the 0DTE wall and the main wall disagree, the 0DTE one is the closer, sharper reaction point and the main one is the bigger structural level.
Each ladder takes the strikes near price (within 1.5%, widening to 5% when the tight band runs short) and ranks them by one greek. The label is the greek's name and a rank: -1 Gamma is the strongest gamma strike, -2 Gamma the second. The dash is the label format, not a negative sign.
The ten strikes with the largest net gamma. Speed bumps and magnets: price slows and clusters around them, and on quiet days it pins to the strongest one nearby. The top three often behave like mini walls; a move that slices through several without pausing says the book has lost control of price.
Vanna is how much delta changes when implied volatility changes. When IV is falling, dealer vanna hedging adds buying and the “vanna rally” walks price up through these strikes; when IV spikes, the same mechanism adds selling. Watch them most on days the VIX moves hard one way.
Charm is how much delta decays as time passes — the slow, steady hedge unwinds that build through the afternoon and into expiration. Charm Zero is where that net flow changes sign; heavy charm strikes below price lean bid, above price lean offer. The Charm Wall is where the effect concentrates, so it often behaves like a soft magnet into the close. A tiebreaker, not a standalone signal.
Delta exposure is the raw size of the hedge inventory at each strike. The Delta Wall holds the most of it; Delta Zero is where the net delta of all open contracts crosses zero. They mark where unwinding, rolling or expiry moves the most.
Two levels within about 0.1% of each other are one price for trading purposes, and a stack is a stronger level than either alone. In the indicator only the stronger line keeps its label (Merge Spacing, default 0.10%) — a Call Wall sitting on a gamma strike shows as the Call Wall. In the GEX Bridge app and the Chrome extension the two share one band with both names (“Call Wall + Put Wall”), so you can see the stack.
Not financial advice. The levels describe where options hedging is concentrated; they are not predictions, signals or trade recommendations. Trading futures involves substantial risk of loss.