Nasdaq says it has applied to extend business day trading hours to 23 hours

Nasdaq said it would file with the Securities Exchange Commission on Monday to apply for near-24-hour stock trading, extending the trading hours for stocks and exchange-traded products from 16 hours on five days a week to 23 hours. Nasdaq currently has three trading sessions on weekdays: premarket trading from 4 a.m. to 9:30 a.m. ET, regular trading from 9:30 a.m. to 4 p.m. ET, and after-hours trading from 4 p.m. to 8 p.m. When Nasdaq implemented "23/5" (a 23-hour trading system on five trading days a week), it planned to have two trading sessions: a day session starting at 4am and ending at 8pm, followed by an hour of maintenance, testing and clearing of trades; a night session starting at 9pm and ending at 4am the next day. The day session will continue to include premarket, regular and after-hours trading sessions, with a 9.30am opening clock and a 4pm closing clock. During the night session, trades executed between 9pm and 12pm will count towards the next day's trading. Under the new plan, the trading week will start at 9 PM on Sunday and close at 8 PM after the end of the day trading session on Friday.