Market Sessions Explained

U.S. markets don't have one single trading window — they have three. Here's what changes between them, and why a lot of the day's biggest moves happen outside regular hours.

The three sessions (Eastern Time)

Outside these windows — overnight and on weekends — U.S. equity markets are closed entirely, though futures and some global markets continue trading and can hint at how the next open will look.

Why moves happen "overnight"

Most companies deliberately report earnings either before the pre-market open or right after the regular close, specifically so the news can be absorbed before (or after) the main session. That's why you'll often see a stock "gap" sharply higher or lower at the next open — the move already happened in thinner pre-market or after-hours trading, and the opening price simply reflects where that lighter-volume price settled.

Because pre-market and after-hours volume is a fraction of the regular session's, prices in those windows can swing further on less money — and sometimes partially reverse once regular-hours liquidity returns.

What "session" and "LIVE" mean on AIOVEL

AIOVEL labels its data by session — for example "MARKETS CLOSED · WEEKEND UPDATE" — so figures are never presented as if they're mid-session when they're not. The LIVE badge and Eastern-time clock indicate the page itself is current and refreshing, not that prices are streaming tick-by-tick; figures are dated snapshots refreshed on a schedule, and any value that isn't available renders as "—" rather than being guessed.