How gamma walls & the HVL flip frame the SPX sessionS&P 500SP_DLY:SPXtechnicalSwift27412Educational post: a simple way to frame an SPX session with dealer-gamma levels (the three horizontal lines on the chart are today's levels). Nothing here is a trade call. 1) Call wall — the strike above spot with the largest call gamma (7800 today). Dealers are long gamma there and sell into rallies, so it behaves as a ceiling / rally-fade zone and often marks the upper edge of the day's range. 2) Put wall / gamma support — the strike below spot with the largest put or positive gamma (the 0DTE gamma wall near 7675 today). It behaves as a cushion / bounce zone; a clean break below it means hedging flips from dampening to chasing the move, so the tape usually gets faster below it. 3) HVL (gamma flip, 7496 today) — the level where net dealer gamma turns from positive to negative. Above it, hedging dampens moves: range days, mean-reversion, GEX magnets work. Below it, hedging amplifies moves: trend days, wider ranges, stops need more room. First thing to check every morning: which side of the HVL price opens on. 4) 1-day cone — the expected move implied by front options (roughly spot x IV x sqrt(1/252), about +/-0.7% today), drawn as a band around spot. Walls inside the cone are the ones most likely to be tested; walls outside it are lower-probability targets. How to draw them: pull today's strikes with the largest net gamma from an options-chain / GEX source, draw horizontal lines at the call wall (resistance), the put wall (support) and the HVL (flip), then add the +/-1-day expected move as two dotted lines. Redraw every morning after the open — gamma levels expire and migrate with open interest and 0DTE flow. Reading the session: above the HVL and between the walls = range / fade-the-edges playbook. Below the HVL = momentum playbook, wider stops, next wall becomes an accelerator rather than support. Combine with price action and volume; these levels are a map of positioning, not a prediction. Not investment advice.