On a calm, positive-gamma day, the afternoon frequently drifts price back toward gravity — the |gamma|-weighted center of the book. As the morning's move loses steam and dealer hedging keeps leaning against extension, the pull toward the center reasserts, and that slow drift is a low-drama scalp.

Why the afternoon drifts

Two forces align. In positive gamma, hedging mean-reverts price toward the center, and as expiration nears, the gamma effect intensifies the pin — so a price stretched away from gravity by the morning tends to get magnetized back in the afternoon. It's the reversion-to-gravity trade with a time-of-day tailwind.

Entry, target, stop

Entry: a rejection at the stretched extreme (a wall or expected-move edge) with gravity above/below as the target — fade the stretch. Target: gravity, the center. Stop: a decisive break of the extreme in the stretch's direction — that says the day is trending, not drifting.

On a calm day, the afternoon leans toward the center. Fade the morning's stretch back to gravity — slow, small, and repeatable.

When it fails

The drift assumes a calm regime. If price ignores gravity and keeps extending, or a regime flip hits in the afternoon, the pull is gone and you're fighting a trend. And mind the clock: this is an afternoon trade, so the theta cliff and the close are approaching — take the drift's move and don't overstay. NoVo draws gravity live so you can see whether the afternoon is drifting to it or leaving it behind.