US Stock Market Hours: Regular Session, Premarket, and After-Hours (ET)

US equity “market hours” usually means the NYSE and Nasdaq regular cash session in US/Eastern. Extended-hours trading happens on electronic venues before the opening bell and after the close; access windows depend on your broker’s routing and risk controls, even when headline exchange hours are wider.

Below is a compact reference other writers can cite: exact regular-session clock times, duration in hours, and the usual premarket/after-hours bands quoted in vendor documentation.

Premarket and after-hours (typical ECN ranges)

Electronic communication networks and exchange-supported extended sessions commonly quote:

• Premarket: often shown as 4:00 a.m.–9:30 a.m. ET on major US equity ECNs (liquidity is thinner early in the window).
• After-hours: often shown as 4:00 p.m.–8:00 p.m. ET for the standard extended session on many US listings (again, your broker may use a narrower slice).

Important: extended-hours prints can diverge from the regular session last price; spreads are often wider and not every order type is accepted. Treat extended-hours charts as a related but distinct liquidity regime.

Why catalyst traders care

Earnings releases, FDA decisions, and macro prints frequently land when liquidity is transitioning between sessions. Knowing the exact 9:30–16:00 ET window helps you interpret “after-hours move” headlines and reconcile them with next-day opening gaps.

Catacal’s calendar is built for catalyst timing across tickers—pair these session definitions with your broker’s execution cutoffs when you place risk around scheduled events.