Gamma Flip Explained: The Regime-Change Level

Before this article, it helps to know what Gamma measures and why it creates two market regimes: read Gamma Explained: The Rate of Change of Delta.

What the Gamma Flip is

The Gamma Flip is the underlying price where the market's aggregate net gamma crosses from positive to negative, or the other way around. It isn't just any strike: it's the equilibrium point that separates the two gamma regimes you saw in the previous article.

$$ \text{Gamma Flip} = S^{} \quad \text{such that} \quad \text{Net GEX}(S^{}) = 0 $$

Where:

$S^{*}$ = the underlying price level where total Net GEX crosses zero.
$\text{Net GEX}(S)$ = the sum of net gamma across the entire relevant options complex, evaluated at a hypothetical underlying price $S$.

Key idea: the Gamma Flip isn't computed on a single strike. It's the result of summing gamma across every relevant strike and expiration, then finding the exact price where that sum crosses zero.

Which regime sits on each side

flowchart LR
    A["Price above the Gamma Flip"] --> B["Long Gamma Regime<br/>Dealers stabilize"]
    C["Price below the Gamma Flip"] --> D["Short Gamma Regime<br/>Dealers amplify"]

Above the Gamma Flip, the aggregate dealer complex is net long gamma: dealers buy dips and sell rallies, compressing the range. Below it, dealers are net short gamma: they sell dips and buy rallies, expanding the range.

Why the Gamma Flip is the most fragile level

Note: the closer price sits to the Gamma Flip, the more unstable the market's behavior. A move of just a few points can flip the entire regime: from a dampening market to an amplifying one, or the reverse.

Far from the Gamma Flip, the current regime tends to hold. Close to it, the market sits in a transition zone where small changes in price (or open interest) can invert the sign of net gamma.

Gamma Flip, Call Wall and Put Wall: a first look at the level skeleton

Level	What it separates	Dealer behavior on each side
Gamma Flip	Long Gamma Regime vs Short Gamma Regime	Buys dips / sells rallies (above); sells dips / buys rallies (below)
Call Wall	Ceiling of the likely range	Sells as price approaches from below
Put Wall	Floor of the likely range	Buys as price approaches from above

The next article develops the Call Wall and Put Wall in detail: for now, the point is that the Gamma Flip is the level that decides how well those two other levels hold.

Numeric example

Example: say the Gamma Flip sits at 19,850 and the underlying trades at 19,920, 70 points above. The market is operating in the Long Gamma Regime: rallies should meet dealer selling and dips should meet dealer buying, compressing the day's range.

If a decline pushes the underlying to 19,830 (below the Gamma Flip), the regime shifts to Short Gamma: the same decline that would have met dealer buying before can now meet additional selling, accelerating the move. Illustrative figures to explain the mechanics, not real levels from any session.

Net GEX crossing zero at the Gamma Flip level

Next step

You now know what the Gamma Flip is and which regime sits on each side. The next article covers the two levels that define the ceiling and floor of the range: the Call Wall and the Put Wall.

Continue with: Call Wall and Put Wall: Structural Walls