Each bar shows total open interest at that strike — calls in green, puts in red. Open interest doesn't tell us who bought vs. sold, but the size of these clusters matters because dealers have to hedge their positions there, and that hedging affects price. Big call clusters above current price often act as ceilings — they're concentration zones where dealer hedging activity intensifies as price approaches, frequently creating "pin" behavior into expiration. Big put clusters below current price often act as floors — but if price actually breaks through them, the gamma flip can accelerate the move down rather than cushion it. These are structural levels worth watching, especially on liquid large-caps and index ETFs where dealer flow dominates. Less reliable on speculative or thinly-traded names.

Each bar is the net dollar gamma dealers carry at that strike, scaled to a 1% move in the stock — green where calls dominate (net long gamma), red where puts dominate (net short gamma). The blue line is the aggregate (cumulative) gamma across strikes. The gamma flip is the price where the dealers' total gamma would cross zero, with every contract's gamma re-priced at that price — not simply where the bars change color: above it dealers are net long gamma, so hedging leans against price (dampening volatility, encouraging pinning); below it they're net short, so hedging chases price (amplifying moves). The call wall — the largest positive-gamma strike above spot — often caps rallies, and the put wall below spot often cushions dips, though a decisive break below it can accelerate selling as short-gamma dealers hedge into the move. Most reliable on liquid large-caps and index ETFs where dealer flow dominates; modeled greeks mean treat single-name reads as directional, not precise.