Is the US stock market turning into the crypto world? Trading 23 hours a day? Amazing! Nasdaq officially announced that the 23-hour trading system (23/5) will go live on December 6, 2026, and has already been approved by the U.S. Securities and Exchange Commission (SEC). By then, the US stock market will only close for 1 hour daily (8:00 PM - 9:00 PM ET) for system clearing and data processing, with trading open continuously for the rest of the time.