Recently, many friends have asked me about pre-market trading in U.S. stocks, so I’ve organized my understanding to share with everyone.

Speaking of pre-market trading in U.S. stocks, it actually refers to the trading that occurs before the New York Stock Exchange and NASDAQ officially open. Usually from 4 a.m. Eastern Time until the market opens at 9:30 a.m. This period may seem insignificant, but it’s very important for investors who want to get ahead.

Why set this time period? My understanding is that corporate announcements, economic data, and major events often don’t wait for the market to open. When important news breaks overnight or during overseas market hours, pre-market trading provides investors with an opportunity to adjust their positions early, before others react. This is the so-called price discovery process — the market begins digesting new information before the official open, rather than rushing in all at once at the open.

The most memorable example for me was Alibaba’s big drop in pre-market on November 16, 2023. Mysterious trust plans under Jack Ma sold 5 million ADS shares, and plans for Hema and Alibaba Cloud’s IPOs were also halted. Once these news broke, the stock price plummeted over 8% in pre-market. By the time the market officially opened, the decline had widened to 8.67%. This shows how pre-market trading directly influences the opening price — if you don’t participate, you might not react in time.

However, pre-market trading also has its limitations. First, you can only place limit orders, not market orders. Why? Because liquidity is scarce during pre-market hours, and with fewer participants, a market order might execute at an unexpected price. Second, not all brokers support pre-market trading, and support times vary. For example, Webull supports from 4 a.m. until the market opens, while Charles Schwab only supports from 7 a.m. to 9:25 a.m. So, before trading in pre-market, you must confirm what times your broker supports.

After discussing pre-market, let’s talk about after-hours trading. After-hours trading refers to trading that continues after the regular session (9:30 a.m. to 4 p.m. Eastern Time), usually until 8 p.m. I’ve noticed that after-hours trading tends to be more stable than pre-market. After a full day of trading, the market has already digested most information, and traders tend to be calmer. For example, NVIDIA’s stock on December 1, 2023, fluctuated over 2% during regular hours, but after hours, the price stabilized within a narrow range. This reflects the market’s eventual discovery of the true price.

If you want to operate during U.S. stock pre-market hours, my advice is to closely monitor news events. When major announcements occur, quickly assess their impact on the stock price and start adjusting your positions early. Another strategy is to set buy or sell prices more aggressive than your ideal levels, taking advantage of the low liquidity in pre-market to potentially gain unexpected profits.

For risk management, it’s crucial to reduce trading volume, be cautious of obviously unreasonable quotes, and stay updated on the latest news. While pre-market and after-hours volatility can be high, they also present opportunities and risks.

Finally, if you find pre-market and after-hours trading too limited, you might consider trading U.S. stocks via CFDs (Contracts for Difference). Many regulated CFD platforms offer 24/5 trading with relatively low costs, which is a good option for investors wanting to break through trading time restrictions. Overall, pre-market trading in U.S. stocks is a valuable tool to understand, but it requires cautious operation and proper risk management.