Most levels are places price reacts. The gamma flip is different: it's the boundary where dealer hedging inverts. Crossing it doesn't just mean support broke — it means the rules of the tape may have just changed.

Above to below

Drop from above the flip to below and you move from a positive-gamma world (dealers dampen, moves get absorbed, extremes fade) into a negative-gamma one (dealers amplify, moves extend, breaks run). A mean-reversion playbook that worked all morning can start handing you losses the moment price is on the other side.

Below to above

The reverse cross is a calming signal: reclaiming the flip from below shifts the tape back toward absorption and pinning. Momentum that felt unstoppable can suddenly stall, because the hedging that was fueling it just flipped to leaning against it.

Crossing the flip is a regime change, not a level break. The question isn't “did support hold” — it's “which market am I in now.”

How to adjust

Treat a decisive, held cross as a signal to switch playbooks: below the flip, respect trend and stop fading; above it, fades and pins come back into play. Watch for a held cross, not a one-bar poke — the flip is a probabilistic map, not a hard line, so a quick wick through it isn't a regime change. Whether the day is a range day or a trend day often comes down to which side of this level price settles on.