Premium Research

We pulled every 15-minute bar of the S&P 500 from 2022 to 2026 and found which window holds each day’s high and low. The opening 15 minutes set the low one day in five, the closing 15 minutes set the high one day in six, and the lunch hour rarely sets either.

Across 1,471 S&P 500 sessions since 2020, we tracked every cross of the prior-day close. A first flip in the lunch hour, 12:15 to 1:30 PM, held to the close just 44% of the time, worse than a coin flip, while flips at other hours leaned toward sticking. The midday recovery was the weakest of all.

Across 1,469 S&P 500 sessions since 2020, we tracked how much of the day’s high-to-low range is in at every 15-minute mark. By 11am it is about 56%, and by 1pm roughly three quarters, so the morning sets the boundaries the afternoon trades inside.

Across 1,468 S&P 500 sessions since 2020, we checked every 15-minute mark to see how often the day's color survives to the 4 PM close. The odds climb from about 70% at the open to 94% by 3:45 PM, and green has held a few points better than red.

We tested every 15-minute S&P bar that jumped or dropped 0.25% to 0.75%. The close barely gets more predictable: up-moves drift on, down-moves stabilize, and the edge is tiny next to the randomness.

Buying the 20-delta call and selling at double, tested at every hour of the session