You know that you need to know the time difference accurately to trade U.S. stocks, right? The time difference between Korea and the U.S. is large, and with daylight saving time it’s easy to get confused—if you don’t handle this properly, your trading plan could fall apart. In particular, it becomes much clearer when you compare the opening times of the Korean stock market and the U.S. stock market.

The three major U.S. exchanges are NYSE, NASDAQ, and AMEX, and all of them have the same trading hours. Regular trading hours are 09:30–16:00 Eastern Time, which converts to 23:30–06:00 in Korea (22:30–05:00 during daylight saving time). Since that means the U.S. stock market opens at 11:30 PM Korean time, after-hours trading is essential.

Pre-market trading is 04:00–09:30 Eastern Time, which is 18:00–23:30 in Korea (17:00–22:30 during daylight saving time), and after-hours trading is 16:00–20:00 Eastern Time, which is 06:00–10:00 the next day in Korea (05:00–09:00 during daylight saving time). The key point is that there’s almost no overlap with the Korean stock market opening hours.

Looking at the trading rules, all three exchanges trade in U.S. dollars, and settlement is completed 2 business days later. What matters most is that, unlike Korea, the U.S. has no limit-up/limit-down price limit bands (no price restriction bands). Because—unlike Korea—the U.S. market operates at night, you may have difficulty responding quickly to sudden declines, so be careful.

You should also check the 2026 market closures in advance. They are fully closed on January 1 (New Year’s Day), January 19 (Martin Luther King Jr. Day), February 16 (Presidents’ Day), April 3 (Good Friday), May 25 (Memorial Day), June 19 (Juneteenth), July 3 (Independence Day), September 7 (Labor Day), November 26 (Thanksgiving), and December 25 (Christmas).

Additionally, early closures occur on the day before Independence Day (July 2), the day after Thanksgiving (November 27), and Christmas Eve (December 24). They close at 1:00 PM Eastern Time, which means they close at 2:00 AM Korean time the next day.

Accurately figuring out the U.S. stock market opening times and setting your trading plan accordingly is the first step toward successful investing. Since information about times and market closures can change from time to time, get into the habit of always checking the latest updates.