SPX GEX HEATMAP 23/07/2026
Welcome! I am glad you are looking to master SPX GEX heatmaps. Before we dive into the mechanics of how options dealer hedging shapes daily price action, I would love to understand your background so I can tailor my explanations perfectly for you.
I understand options basics but am new to GEX.
To understand GEX heatmaps, we have to start with the quiet giants of the options world: the market makers (also known as ). Whenever you buy a call or sell a put on the S&P 500, you are almost certainly trading with a market maker rather than another retail trader.
Because dealers are in the business of facilitating trades—not taking directional bets—they must stay neutral. They achieve this through a process called delta hedging. If they sell you a call option, they are technically 'short' the market, so they immediately buy a calculated amount of underlying stock or futures to neutralize that directional risk.
This is where (GEX) comes into play. Gamma measures how fast a dealer's delta (their directional exposure) changes as the market moves. If the market shifts, their neutral state is thrown off, forcing them to mechanically buy or sell more stock to re-balance. GEX is simply the estimated dollar value of stock they are forced to trade for every 1% move in the S&P 500.