How to Read the Gamma Exposure Map
The Gamma Exposure Map is the single most useful screen on the platform, but only if you know what the lines mean. This guide walks through each element and the trading implication of every configuration.
Net GEX: the regime switch
Net GEX aggregates dealer gamma across all strikes. Positive net GEX means dealers hedge against price — they sell strength and buy weakness, compressing realized volatility. Negative net GEX means they hedge with price, amplifying every move. Regime first, trade idea second.
Zero Gamma: the flip level
Zero Gamma is the price where aggregate dealer gamma crosses from positive to negative. Above it, expect mean reversion and range. Below it, expect trend and expansion. Price accepting through the flip is the highest-information event on the intraday tape.
Call Wall and Put Wall
The Call Wall is the strike with the largest positive gamma concentration above spot — it behaves like a magnet and then a ceiling in long-gamma regimes. The Put Wall is its mirror below spot and often marks where hedging flows stabilize a selloff. Walls are strong until they are broken, and a broken wall frequently becomes the next acceleration point.
- Long gamma + price between walls = fade extremes toward the mid.
- Short gamma + price below the flip = trade continuation, not reversion.
- Walls shift as new flow prints. Refresh intraday; stale levels are worse than none.
Max Gamma vs Call Wall
Max Gamma is the single largest gamma strike anywhere on the chain; the Call Wall is specifically the largest above spot. They often coincide but not always, and confusing them leads to fading the wrong level. The map labels each separately for that reason.
A worked example
Suppose SPX spot is 5,000, Zero Gamma sits at 4,970, the Call Wall is at 5,050 and the Put Wall is at 4,930. Net GEX is strongly positive. The read: price is above the flip in a positive-gamma regime, so expect chop between 4,930 and 5,050 with dealer hedging fading pushes toward either wall. A break and acceptance below 4,970 would flip the whole playbook toward trend continuation instead of mean reversion.
- Distance from spot to flip tells you how 'live' the regime-change risk is today.
- Wall-to-wall width tells you the expected daily range in the current regime.
- A wall sitting exactly at a round number or known support adds confluence.
Common mistakes reading the map
The most frequent error is treating a wall as a hard price target rather than a probability-weighted zone — walls move as new option flow prints, sometimes by 10-20 points intraday on a busy day. The second is ignoring net GEX sign entirely and only looking at wall locations, which leads to fading strength in a negative-gamma trend day, a low win-rate trade. The third is applying index-style GEX logic to a thinly traded single name where the options market is too small to drive meaningful dealer hedging.
Key takeaways
- Determine the regime from Net GEX before you look at any strike.
- Zero Gamma is the line that changes how the market behaves, not just where it sits.
- Walls are levels of dealer hedging density, not support/resistance drawn by hand.
Practice this in the terminal
FAQ
How often should I refresh the map?
Intraday: every 15–30 seconds for 0DTE work. For swing positioning, once at the open and once mid-session is enough.
Does GEX work on single names?
Yes, but only where options volume is meaningful. Index products and mega-cap names give the cleanest signal.
What if price is sitting exactly between two walls with no clear trend?
That is the base case in a positive-gamma regime: expect range-bound chop and treat the midpoint between walls as a magnet. Fade extremes toward the middle rather than forcing a directional trade.
Can the walls disappear intraday?
Yes. As options expire or large positions are closed, the strikes with the most gamma concentration shift, sometimes abruptly. Always check the current map rather than relying on a level noted earlier in the session.
Test your knowledge
2 questions. Score 80% or higher to count this guide as mastered.
Keep going
Educational content only. Options involve substantial risk and are not suitable for every investor. Nothing here is financial advice.