SPX 0DTE Glossary
Every term SPXXL uses, explained for 0DTE options traders. 22 terms across session types, metrics, option structures, and core concepts.
A session where price oscillates around a central value area with no directional conviction — the most common session type for SPX.
A session with sustained directional movement from open to close — price trends in one direction with minimal retracement.
A volatile session with range expansion beyond normal boundaries — often triggered by macro catalysts or institutional repositioning.
A sharp upward session driven by short sellers closing positions — creates aggressive buying pressure that accelerates as stops are triggered.
A session where price probes beyond key levels to trigger clustered stop-loss orders before reversing — designed to trap directional traders.
A session with unusually low range and volume — price consolidates tightly as the market coils before a potential expansion move.
SPXXL's proprietary projected closing price range for SPX, computed using session classification, gamma exposure, and intraday momentum.
The price range established during the first 30 minutes of trading (9:30-10:00 AM ET) — a key reference for the entire session.
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.
Options that expire on the same day they are traded — the fastest-growing segment of the options market with unique risk/reward characteristics.
A charting methodology that organizes price by time and volume to reveal value areas, balance, and auction theory — the foundation of session classification.
The current state of market depth and order flow quality — determines how easily large orders can be executed without moving the market.
SPXXL's public database of every classified trading session — a searchable, transparent record of engine accuracy across 297+ trading days.
SPXXL's public accuracy dashboard showing win rate, streak data, and Engine Edge score — graded daily at 4:05 PM ET.
The Standard & Poor's 500 Index — the benchmark U.S. equity index and the underlying for the world's most liquid options market.
SPXXL's composite accuracy score measuring classification quality, structure recommendations, and calibration across confidence levels.
The CBOE Volatility Index measuring expected 30-day SPX volatility — the market's "fear gauge" and key input to session classification.
The implied volatility of at-the-money SPX options — reflects the market's real-time pricing of expected movement for the current session.
A defined-risk options strategy that profits from directional movement — SPXXL's primary recommended structure for most session types.
A four-leg credit spread that profits when price stays within a defined range — ideal for Balanced Day and Volatility Compression sessions.
A three-strike options strategy that profits when price settles near a target price — precision tool for the Close Zone phase.