Recently, I’ve noticed that many people still have misconceptions about pre-market trading in the United States, so I’ll organize my understanding here.

Simply put, pre-market trading in the U.S. is the period before the New York Stock Exchange and NASDAQ officially open (9:30 AM Eastern Time), during which investors can buy and sell stocks in advance. Trading usually starts as early as 4:00 AM. Why is this period set up? Mainly because unexpected news doesn’t wait for the market to open. Corporate announcements, economic data, overseas market movements—these can happen overnight, and pre-market trading allows investors to react ahead of time.

I’ve noticed that many overlook a detail—the liquidity during pre-market is much lower than during regular hours. What does this mean? It means your orders might not get filled, or the prices could be very extreme. Therefore, exchanges restrict pre-market orders to limit orders only, prohibiting market orders. This rule may seem troublesome, but it’s actually to protect investors.

For example, at the end of 2023, Alibaba’s situation illustrates this well. News about Jack Ma’s team planning to sell a large amount of shares, combined with the suspension of IPO plans for Hema and Alibaba Cloud, caused the stock price to plunge over 8% in pre-market. When the market opened, the stock was down 8.67% compared to the previous day’s close. This demonstrates the power of pre-market trading—significant news can directly change the opening price.

After-hours trading is similar, extending from market close (4:00 PM to 8:00 PM Eastern Time). Interestingly, after-hours tends to be calmer than pre-market. For example, NVIDIA’s performance on December 1, 2023, showed that during regular trading hours, volatility exceeded 2%, but after-hours remained stable within a narrow range. This is because less new information is available, giving the market time to digest what’s out there, and the final prices tend to be close to the next day’s opening price.

To participate in U.S. pre-market trading, you need a broker that supports this feature. Different brokers have different time windows—for example, Webull supports trading from 4:00 AM ET, Charles Schwab from 7:00 AM, and Fidelity from 8:00 AM. This is very important; choosing the wrong broker means you can’t place orders at the optimal times.

Regarding trading strategies, I recommend closely following news events. Pay attention to company fundamentals during normal hours, and quickly adjust your positions when major positive or negative news breaks. You can also try setting buy prices below your ideal level or sell prices above expectations—since volume during pre-market and after-hours is sparse, such strategies can often yield unexpected gains.

Risk management is crucial. Low liquidity means you should reduce the size of individual trades, stay alert for abnormal quotes, and keep a close eye on news developments. Some investors use Contracts for Difference (CFDs) to bypass exchange hours, as CFDs can generally be traded 24/7 without restrictions from pre-market or after-hours.

Overall, pre-market trading in the U.S. is a double-edged sword. It offers the chance to react early to major events, but also involves higher liquidity risks and greater price volatility. If you want to participate, make sure to fully understand your broker’s policies, set stop-loss orders, and avoid greed. Opportunities do exist during this period, but only if you are cautious enough.