SPX dealer gamma — Tuesday, March 28, 2023
dealer positioning for the session, reconstructed from the 0DTE options tape
These are the CLOSING levels for 2023-03-28. Where the SPX dealer book stands right now — the current zero-gamma flip, call resistance and put support — is on /now, free, at least fifteen minutes behind the tape.
SPX opened at 3,969.98 and closed at 3,970.86, up 0.02% on the session (range 3,951.83–3,978.29). The close sat 42.7 points above the zero-gamma flip at 3,928.2 — dealer hedging in vol-dampening territory. Call resistance 3,970, put support 3,900. 0DTE ATM IV opened at 14.2%.
Price stayed on one side of the flip for the whole session. The tape spent 31% of the day above VWAP. The expected-hold band 3,928.2–4,013.6 contained the entire session.
| Open → Close | 3,969.98 → 3,970.86 (+0.02%) |
| Session range | 3,951.83 – 3,978.29 |
| VWAP at the close | 3,965.91 |
| Zero-gamma flip | 3,928.2 |
| Call resistance | 3,970 |
| Put support | 3,900 |
| Expected-hold band | 3,928.2 – 4,013.6 |
| 0DTE ATM IV at the open | 14.2% |
| Regime at the close | positive gamma |
| Close vs flip | +42.7 |
| Net-gamma percentile | 100 |
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. Measured across the whole archive: how often these levels hold and how far SPX travels before the close.
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.