The gamma flip is reconstructed from the current options book, which means it's only as current as the data behind it. A flip level you saw on yesterday's close is a snapshot of yesterday's positioning, and positioning doesn't sit still overnight or into the open.

What changes overnight and at the open

Three things move it. Overnight repositioning: futures move, and expectations shift, changing which strikes matter. Fresh 0DTE open interest: because SPY expires every day, a whole new same-day book builds in the first hour, and that near-term gamma reshapes the flip. Time and price decay: as the day progresses and spot moves, the gamma profile itself changes shape. By 10 a.m., the level can sit somewhere different than the close-of-yesterday number implied.

A flip is a live estimate, not a line you can carry over from yesterday. Trade the current one or don't trade it.

Why it matters

If you're using the flip to decide fade-or-chase and the level is stale, you can think you're comfortably in positive-gamma territory when the live flip has actually crept up beside you. That's how the framework misfires, not because it's wrong, but because the input is old.

The takeaway

Treat any flip number with a timestamp. The value is in a continuously recomputed level that reflects this morning's book, not last night's. NoVo re-estimates the flip and the rest of the dealer map through the session for exactly this reason — the map is only useful if it's current.