Call Wall
The strike with the highest positive dealer gamma. Acts as resistance because dealers sell into rallies toward it. Often defended fiercely.
What is GEX?
Gamma Exposure (GEX) measures where options market makers are positioned and where they will need to hedge as the underlying moves. It's one of the most powerful tools for understanding why price gravitates toward certain strikes, why some levels act as walls, and when the market is set up for mean reversion versus momentum.
ESGex calculates the full GEX surface for SPX options every session, identifies the key structural levels, converts them to ES futures equivalents, and posts the analysis automatically — no signup, no paywall, no spam.
Posting Schedule
13:30 GMT
Pre-Session
Levels for the day ahead, posted before the NY open.
14:30 GMT
NY Open
Refreshed snapshot as cash market opens.
17:00 GMT
Mid-Session
Mid-day update with latest dealer positioning.
21:00 GMT
Close
End-of-day snapshot for overnight planning.
Glossary
Put Wall
The strike with the largest negative dealer gamma exposure. Acts as support because dealers buy into selloffs toward it.
Gamma Flip
The price where dealer net gamma crosses zero. Above flip: positive gamma regime, mean reversion expected. Below flip: negative gamma, momentum and volatility.
Vol Trigger
A downside inflection point where volatility behaviour shifts. Breaking below typically increases realised volatility and signals regime stress.
Magnet
The strike with the strongest pinning effect from combined gamma and open interest. Price tends to gravitate here, especially into expiry.
0DTE Magnet
The Magnet level computed using only same-day-expiry options. Important for intraday flow on heavy 0DTE days.
GEX Levels (1-5)
Top-ranked secondary strikes by combined GEX magnitude and confluence (round numbers, clusters, OI alignment).
DEX Bias
Net Delta Exposure. Bullish when dealers are net long delta (suppressing volatility on rallies), bearish when net short.
Spread (ES-SPX)
The premium of ES futures over SPX cash. Reflects carry, dividends and funding. Used to convert SPX-based levels into actionable ES prices.
About
ESGex is built and maintained by Anthony, an E-mini S&P 500 futures trader based in London. The bot uses delayed CBOE options data, a proprietary GEX calculation engine derived from auction market theory and Jim Dalton's TPO methodology, and posts automatically via the X API.
Follow the trader behind the bot at @nasdaqblog for live trade commentary, market structure analysis and longer-form thoughts.
Disclaimer: ESGex is for educational and informational purposes only. The levels
published are derived from delayed market data and may differ from real-time conditions. Nothing
here constitutes financial advice. Trade your own conviction and manage your own risk.