Pre-market trading in the US Stock Market: Overview and Impact

The pre-market trading of the US Stock Market is a time period during which investors can conduct trades before the official trading begins. It typically takes place between 4:00 AM and 9:30 AM Eastern Time. The main purpose of this trading is to allow investors to quickly respond to sudden news and facilitate price discovery.

Pre-Market Trading Hours

• NYSE and NASDAQ: US Eastern Time 4:00-9:30
• CBOE: US Eastern Time 8:00-9:15

Trading Rules and Features

There are several important rules and characteristics in pre-market trading:

• Only limit orders are allowed (market orders are not permitted)
• Orders through a brokerage firm that supports pre-market trading
• The trading volume is low, and the participants are also limited.
• The price fluctuations are large, and liquidity is low.

Impact on Opening Price

Pre-market trading can have a significant impact on the opening price of the day. When important news is announced, investors may adjust their expectations in the pre-market, which can lead to an opening price that differs greatly from the previous day's closing price.

Trading Strategies and Risk Management

When trading in the pre-market, it is important to pay attention to the following points:

• Trading closely monitored news events
• Setting a lower buy order price or a higher sell order price
• Reduction of trading volume and frequency
• Be cautious of unnatural price offers
• Close monitoring of related information

Comparison with Aftermarket Trading

After-market trading occurs from 16:00 to 20:00, after regular trading hours. Like pre-market trading, it has low trading volume and a limited number of participants. However, after-market trading differs in that it provides a longer period for price discovery.

Utilizing Technical Analysis

In pre-market trading, the following technical indicators are particularly useful:

• Volume Indicator: Tracks changes in trading volume to identify important trends.
• Moving Average: Understanding short-term price trends
• Volatility Indicator: Measures the magnitude of price fluctuations and is used for risk management.

By combining these indicators, you can analyze pre-market trends more accurately and make informed decisions.

Actual Trading Cases

On October 9, 2025, in pre-market trading following the quarterly earnings announcements of major technology companies, the stock price of leading companies in the AI sector rose by 7%. This movement reflects investors' reactions to better-than-expected performance and future growth prospects.

Overall, pre-market trading provides investors with additional trading opportunities, but it comes with high risks, requiring careful consideration. Proper strategies and meticulous risk management are key to success.