SPX dealer gamma positioning

Friday, January 6, 2023 · reconstructed from the 0DTE options tape

SPX opened at 3,836.64 and closed at 3,894.32, up 1.50% on the session (range 3,812.14–3,906.17). The close sat 89.3 points below the zero-gamma flip at 3,983.6 — dealer hedging in vol-amplifying territory. Call resistance 3,895, put support 3,900. 0DTE ATM IV opened at 20.4%.

Price crossed the flip 2 times, first at 15:54 ET. The tape spent 94% of the day above VWAP. The session traded outside the expected-hold band 3,892.8–3,896.4 at some point.

Open → Close3,836.64 → 3,894.32 (+1.50%)
Session range3,812.14 – 3,906.17
VWAP at the close3,873.46
Zero-gamma flip3,983.6
Call resistance3,895
Put support3,900
Expected-hold band3,892.8 – 3,896.4
0DTE ATM IV at the open20.4%
Net-gamma percentile98
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The terminal replays the full session minute by minute: dealer gamma, vanna and charm by strike, the flip and hold levels as they moved, IV and realised vol side by side. Every historical session is free and needs no account. New to these terms? Start with what GEX is.

Measurements are model output derived from public trade and quote data; they are approximations and can be wrong. Nothing here is investment advice — see the Terms.