Power hour is the final hour of the trading day (3–4pm ET), when volume and volatility surge as institutions position into the close. It’s one of the day’s most active windows.

What drives it

Several forces converge: institutions executing end-of-day orders, charm and gamma hedging intensifying into expiration, MOC imbalances building toward the auction, and traders squaring positions before the bell. After the midday drift, this rush of activity revives volume and movement — sometimes producing the day’s strongest trend, sometimes a violent chop.

Trading power hour

Power hour can offer real momentum moves — but on 0DTE it’s treacherous: maximum gamma, fast decay, widening spreads, and the pin all in play. It’s where experienced traders can find clean trends and where the undisciplined get chopped up into the bell.

Power hour is the market’s second wind — big volume, big moves, and big risk on 0DTE. Trade it with respect or watch from the sidelines.

What it means for a scalper

Read the gamma regime and the imbalance to know whether power hour will trend or pin. Many scalpers are flat by 3pm to avoid the 0DTE close risk. If you trade it, tighten discipline — the last hour rewards it and punishes its absence.