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DarkGamma
dealer gamma exposure · SPY 560 · 230 contracts · as of 2026-08-28 · delayed sample data
Spot
560
SPY
Net GEX / 1%
$+278M
dealer $gamma per 1% move
Regime
Long γ
mean-reverting / pinned
Flip point
558
spot above by 0.3%
Call wall
570
upside magnet / resistance
Put wall
550
downside magnet / support
What this means today
SPX is in long-gamma territory (net GEX $+278M). Dealer hedging leans against moves, so intraday ranges tend to compress and price gravitates toward high-gamma strikes. Watch the call wall 570 as resistance and the put wall 550 as support. A break below the flip 558 would flip the regime to short gamma — the character of the tape changes there.
GEX vs spot — the flip profile
Gamma by strike (near spot)
0DTE gamma by strike — today's pin/decay map
Methodology
Dealer-positioning convention (SqueezeMetrics-style): dealers are assumed long calls, short puts. Per contract, GEX = Γ × OI × 100 × S² × 0.01 (dollar gamma per 1% move); calls count positive, puts negative. The flip point is found by recomputing Black-Scholes gamma across a grid of hypothetical spot levels and locating where aggregate net GEX crosses zero. Walls are the near-spot strikes carrying the most call / put gamma. This is a positioning convention, not ground truth — real dealer books are not observable. Source: pipelines/gex_pipeline.py.