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GEX on Reddit: how to read a gamma exposure chart

Read a GEX chart in four steps. Find spot. Find the gamma flip and note whether spot is above it (calmer, mean reverting) or below it (faster, trending). Mark the call wall above and the put wall below as likely stall zones. Then check how concentrated gamma is in today's expiry, which fades fastest.

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The four things on the chart

Net GEX by strike: bars to the right are positive gamma, where dealer hedging leans against moves. Bars to the left are negative gamma, where hedging leans with them.

Call wall: the strike with the most call gamma above spot. Rallies often slow there. Put wall: the strike with the most put gamma below spot. Selloffs often slow there.

Gamma flip: the price where net GEX changes sign. It is the line between the calmer and the faster regime.

Expiry mix: gamma from contracts expiring today disappears at the close, so a wall built on 0DTE options can vanish by tomorrow.

A worked read

Spot 733, flip 757, call wall 760, put wall 730. Spot is below the flip, so the session is in negative gamma: moves can extend. The put wall is close below at 730, so a test of it is the first thing to watch. A reclaim of 757 would switch the regime to positive gamma and make 760 a likely ceiling.

Questions

What does negative GEX mean?
Dealers are net short gamma, so their hedging buys into rallies and sells into drops. That tends to make moves larger and volatility higher.
Is the call wall resistance?
Often a stall zone, not a hard ceiling. Price can break through, especially when the gamma there comes from short-dated contracts that expire soon.
Where can I see a GEX chart free?
Obelion shows net GEX by strike, the gamma flip and call and put walls for free, with no sign-up.

Related

For education only, not financial advice. See the disclaimer.

GEX Reddit Guide: How to Read a Gamma Exposure Chart Step by Step | Obelion