Learn · SPY 0DTE · gamma

Gamma flip for SPY: what it is and how to trade it

The gamma flip (sometimes “vol trigger” or “zero-gamma level”) is the single most useful regime line for SPY same-day options. It tells you whether dealers are likely to dampen the next move or amplify it — which decides whether fades or breaks are the higher-probability play.

What the flip actually is

Market makers hedge the options they hold. Whether that hedging stabilizes or destabilizes price depends on the sign of their net gamma. Aggregate gamma across strikes and you get a level — the flip — where that net sign changes relative to spot.

Positive gamma vs negative gamma

• Spot above the flip → positive gamma. Dealers hedge against the move (sell rips, buy dips), which compresses range. Mean-reversion and fades into the call/put walls tend to work.
• Spot below the flip → negative gamma. Dealers hedge with the move (sell weakness, buy strength), which expands range. Breaks and momentum dominate; naive fades get run over.

Same setup, opposite behavior. That is why reading the flip first is worth more than any single pattern.

How to trade around it

1. Locate the flip relative to spot to set today’s bias (fade-friendly vs break-friendly).
2. Watch reactions at the flip itself. A reclaim (failed break back above) or a clean break through it is often the highest-information event of the session.
3. Confirm with a one-minute close before acting — not a wick testing the line.
4. Define invalidation at a close back through the flip. See invalidation stops.

The classic mistake

Fading a put wall after the flip has already broken is the textbook way to get hurt. In negative gamma, the same dealer hedging that supported price on the way up reinforces the selloff on the way down. Wait for a reclaim or trade with the break — do not catch the knife on hope.

How the Desk shows it live

0DTE Confluence builds the flip from a live options-chain map and marks it on the Decision Desk alongside the walls and expected-move band, so you can see at a glance whether you are in a fade-friendly or break-friendly regime — then it only grades setups that agree with structure and flow.

Frequently asked questions

Further reading on this site

• SPY 0DTE gamma walls explained
• SPY call wall & put wall — fade vs break
• SPY 0DTE strategy framework