Close Zone™
SPXXL's proprietary projected closing price range for SPX, computed using session classification, Gamma exposure, and intraday momentum.
The Close Zone™ is SPXXL's proprietary intraday price projection that estimates where SPX will settle at 4:00 PM ET. Unlike simple support/resistance levels, the Close Zone dynamically recalibrates throughout the session based on real-time data.
The Close Zone projection integrates:
- ●Current session classification and confidence
- ●Dealer Gamma exposure at nearby strikes
- ●Intraday momentum and VWAP deviation
- ●Volume profile and value area migration
- ●Theta decay curves for nearby expirations
- ●Historical session-type close patterns
The Close Zone narrows as the session progresses — it's widest at 9:30 AM and tightest in the final hour. SPXXL's dashboard displays the projected range with confidence bands.
For 0DTE traders, the Close Zone is the core decision input: if your spread target zone aligns with the Close Zone, the session is working in your favor. If price is drifting away from your structure, the engine signals to adjust or close.
The Close Zone becomes most actionable during the "Close Zone Phase" (3:30-4:00 PM ET) when theta acceleration reaches maximum velocity.
Related Terms
The rate at which an option loses value as time passes — accelerates dramatically for 0DTE options as expiration approaches.
The aggregate Gamma positioning of options market makers — determines how dealer hedging amplifies or dampens SPX price moves.
The options-implied price range SPX is expected to stay within by the close — derived from ATM implied volatility using the 1-standard-deviation (68%) probability envelope.
Options that expire on the same day they are traded — the fastest-growing segment of the options market with unique risk/reward characteristics.
The strike price where the largest dollar amount of SPX option premium expires worthless — a settlement magnet that price often drifts toward into expiration as dealers hedge toward the pin.
The odds that SPX will trade through a given strike at any point before expiration — roughly double the probability of expiring beyond it, and the single most misunderstood risk number in 0DTE options trading.