GEX (Gamma Exposure)

GEX is the aggregate dealer-gamma exposure in billions of dollars, sourced from a third-party dealer-gamma analytics feed. It measures how the entire options dealer book is positioned across the S&P 500.

What it measures

When dealers are long gamma (GEX positive), they hedge counter-trend: they buy dips and sell rallies. This dampens realized volatility — the market reads as well-behaved, mean-reverting.

When dealers are short gamma (GEX negative), the hedging flips: dealers must buy strength and sell weakness to neutralize their option books. This amplifies moves in both directions — small flows trigger forced dealer buying or selling that accelerates the trend.

The sign is the regime switch. The magnitude is the amplification.

Bands

The 5-band gex_sign classifier captures both sign and magnitude:

The transition between negative and deep_negative is the most operationally meaningful — it’s the threshold for the squeeze_setup composite’s gamma_deep_negative trigger.

How to read it on the dashboard

• Card: positive → green; deep_negative → red.
• Sparkline: 30-day trend of raw GEX. Sharp drops into negative territory precede most short squeezes; sharp recoveries past 0 mark stabilization.
• Companion signals: pair with Gamma Walls (brokerage option-chain per-strike profile — tells you where the dealer pivot is) and DIX (whether institutions are accumulating into the positioning).

Why GEX matters more than direction

A “deep_negative GEX + breadth weak + AAII bear extreme” stack historically precedes the kind of two-day rip that catches everyone mis-positioned. The squeeze_setup composite codifies this — four triggers, primed at three.

Source

Daily dealer-gamma analytics CSV download (app/sources/darkpool.py). Updates once per trading day, end of session. Available to the matcher + dashboard via the daily_signals.gex column.