The typical hours of a trading session for major stock exchanges like the New York Stock Exchange (NYSE) and NASDAQ are divided into three main phases: pre-market, regular trading, and after-hours sessions. The regular trading session runs from 9:30 a.m. to 4:00 p.m. Eastern Time (ET), Monday through Friday, excluding market holidays. This is the core period when the majority of trading activity occurs, with high liquidity and participation from institutional and retail investors.

The pre-market session begins earlier, typically at 4:00 a.m. ET and lasts until the market opens at 9:30 a.m. ET. During this time, investors can react to overnight news or earnings reports, but trading volumes are lower, and price movements can be more volatile.

The after-hours session follows the regular session, starting at 4:00 p.m. ET and ending at 8:00 p.m. ET. Like the pre-market session, after-hours trading allows investors to respond to late-breaking news, but it also experiences lower liquidity and wider bid-ask spreads.

These extended hours provide flexibility for traders but come with increased risks due to reduced participation and higher volatility. The regular session remains the most active and reliable period for executing trades with optimal liquidity and price stability.