What is a gamma squeeze?
A gamma squeeze happens when heavy call buying forces the dealers who sold those calls to buy the stock as it rises, to stay hedged. Their buying pushes the price higher, which raises the calls' delta, which forces more buying. The loop runs until call demand fades or the calls expire.
How the loop works
A dealer who sells a call is short delta, so they buy shares to neutralise it. Gamma is how fast that delta changes as the price moves. Near the strike and close to expiry, gamma is highest, so a small move up demands a large amount of extra stock.
When traders keep buying short-dated, out-of-the-money calls, dealers keep adding to that short gamma position. Every uptick then needs more shares bought, and that buying is what turns a normal rally into a squeeze.
What the setup looks like in GEX data
Gamma exposure (GEX) adds up dealer gamma across every strike. A squeeze is most likely when total GEX is negative or close to zero and price sits just below a strike with a large block of call open interest. In that state dealers hedge in the direction of the move instead of against it.
The opposite state, large positive GEX, tends to pin a stock: dealers sell into rallies and buy dips, which damps the move. That is why the same call buying can squeeze one stock and stall in another.
Why squeezes end
The fuel is new call buying. Once it slows, dealers stop adding hedges. At expiration the calls and their hedges disappear together, and the hedge selling that follows can reverse the move quickly. Squeezes also burn out when implied volatility jumps, because higher IV flattens gamma near the strike.
Questions
- Is a gamma squeeze the same as a short squeeze?
- No. A short squeeze is short sellers buying back stock to close losing positions. A gamma squeeze is options dealers buying stock to hedge calls. They can happen at the same time, which is what made the largest meme stock moves so violent.
- Can you predict a gamma squeeze?
- You can see when the conditions are present: negative or low gamma exposure, heavy short-dated call open interest just above the price, and rising call volume. You cannot know whether new buying will arrive to start the loop.
- Does this apply to indices like SPX?
- The mechanics are the same, but index options markets are so large and two-sided that a true squeeze is rare. Index gamma matters more for whether daily moves are damped or amplified.
Related
- 0DTE options explained
- Free gamma exposure chart
- SPX vs SPY gamma exposure
- Does max pain work?
- Open interest vs volume in options
For education only, not financial advice. See the disclaimer.