What the gamma flip is, and why the tape feels different on either side of it

Options dealers spend most of their day doing one thing: staying hedged. Every contract they sell to the public leaves them with exposure to the index, and they offset it by buying or selling the underlying. That hedging is mechanical, it is large, and it changes direction at a specific price. Traders call that price the gamma flip.

Above the flip

When price sits above the flip, dealers as a group are long gamma. As the index rises, their hedge requires them to sell a little; as it falls, to buy a little. Their flow pushes against whatever the market just did. Rallies get capped, dips get bought, and the day tends to feel like it is being held in a range.

Below the flip

Below it the sign changes. Now a rising index forces dealers to buy, and a falling one forces them to sell. Their flow pushes with the move. That is why the same headline can produce a 20-point wobble one day and a 100-point run the next: the news was similar, the hedging regime was not.

What the flip is not

It is not a forecast, and it is not a line that price cannot cross. It moves through the day as positioning changes, and it is estimated, not observed, because it depends on how the open interest is distributed and who is holding which side. Two vendors will give you two slightly different numbers. What matters is the behaviour on each side, which is remarkably consistent, and whether price is reclaiming or losing the level rather than the exact print.

How traders use it

Mostly as a question: which kind of day is this? Above the flip, fading extremes toward the middle has the structure on its side. Below it, waiting for confirmation before fading anything does. The flip does not tell you what to do; it tells you what the market is likely to do with what you do.