Extended hours trading is the buying and selling of securities outside the U.S. stock market's regular session, which runs from 9:30 a.m. to 4:00 p.m. Eastern Time. It includes pre-market trading before the open, after-hours trading after the close, and, through some brokers and trading venues, overnight trading.
Extended hours trading gives investors a way to respond to earnings reports, economic news, and other events before the regular market opens. The trade-off is less liquidity, wider bid-ask spreads, greater volatility, and fewer order types than investors typically find during regular market hours.
Extended Hours Trading at a Glance
| Trading Session | Common U.S. Hours | What It Means |
|---|---|---|
| Regular session | 9:30 a.m. to 4:00 p.m. ET | The main exchange trading session |
| Pre-market trading | Often 4:00 a.m. to 9:30 a.m. ET | Trading before the regular session opens |
| After-hours trading | Often 4:00 p.m. to 8:00 p.m. ET | Trading after the regular session closes |
| Overnight trading | Varies by broker and security | Trading during part of the night, where available |
Hours vary by broker, exchange, security, and trading venue. Some brokers offer shorter pre-market sessions. Others provide overnight access for selected stocks and exchange-traded funds.
How Does Extended Hours Trading Work?
During extended hours, your broker routes orders to an exchange or alternative trading system that supports trading outside the regular session. Fewer investors participate at these times, so there may be fewer buyers and sellers for a security.
Consider a company that releases its quarterly results at 4:05 p.m. ET:
- The company publishes its results after the regular session closes.
- Investors place after-hours orders in response.
- The stock price moves based on the orders available at that time.
- The price may move again when more investors return for the next regular session.
The extended-hours price does not become the stock's official closing price. The regular-session closing price remains the official close. The next day's opening price is set by supply and demand around the market open.
What Are the Main Benefits?
Reacting to Important News
Extended hours let investors respond to earnings releases, company announcements, economic data, and other market-moving information before the next regular session. Many corporate announcements take place before the market opens or after it closes.
Trading Around Your Schedule
Investors who cannot trade between 9:30 a.m. and 4:00 p.m. ET may use pre-market or after-hours sessions at a more convenient time.
Convenience does not change the trading conditions, though. A broker may accept an order outside regular hours even when fewer buyers and sellers are available.
Accessing Overnight Markets
Some brokers offer overnight trading for selected U.S. stocks and exchange-traded funds. This access is not universal. The eligible securities, trading hours, and order rules depend on the broker.
What Are the Risks?
Lower Liquidity
Extended hours generally have fewer participants and fewer orders than the regular session. Your order may be partially filled, filled at a less competitive price, or not filled at all.
Wider Bid-Ask Spreads
The bid is the highest price a buyer is offering. The ask is the lowest price a seller will accept.
When fewer traders are active, the gap between the bid and ask can widen. That gap raises the cost of entering or exiting a position.
Higher Volatility
Prices can move sharply when a company releases news and only a small number of orders are available. A stock that rises or falls substantially after hours may move in the opposite direction when regular trading resumes.
Prices May Differ Between Venues
The National Best Bid and Offer, commonly called the NBBO, is generally published during regular trading hours. During extended hours, markets may not be linked in the same way. One trading venue may therefore display a worse price than another venue trading the same security.
The Next-Day Opening Price Can Be Different
An after-hours price does not guarantee the next day's opening price. New orders, overnight news, and broader market conditions can cause the stock to gap before the regular session begins.
Fewer Order Types May Be Available
Many brokers restrict extended-hours trading to limit orders. A broker may also set separate rules for order duration, cancellation, eligible securities, and unfilled orders.
Should You Use a Market Order or Limit Order?
A limit order is generally the more controlled choice for extended hours trading.
A limit order tells your broker to buy or sell only at a specified price or better.
- A buy limit order for $50 can execute at $50 or less.
- A sell limit order for $50 can execute at $50 or more.
A limit order does not guarantee execution. If the market never reaches your limit price, the order may remain unfilled.
A market order may execute more quickly, but the final price can be difficult to predict in a thin or fast-moving extended-hours market.
Extended Hours Trading Versus Regular Trading
| Feature | Regular Hours | Extended Hours |
|---|---|---|
| Trading volume | Usually higher | Usually lower |
| Liquidity | Generally stronger | Often weaker |
| Bid-ask spreads | Often narrower | Can be wider |
| Volatility | Usually more stable | Can be higher |
| Order types | More widely available | Often restricted |
| Market price information | More broadly consolidated | May differ by venue |
| Execution certainty | Generally higher | Partial or no execution is more likely |
Who Is Extended Hours Trading Suitable For?
Extended hours trading may suit experienced investors who:
- Understand limit orders and bid-ask spreads
- Need to respond to time-sensitive news
- Accept that an order may not execute
- Can tolerate sharp price movements
- Have checked their broker's session times and restrictions
It is usually less suitable for investors who want the highest liquidity, the narrowest spreads, and the most predictable execution. For many long-term investors, waiting for the regular session can reduce execution-related risks.
Bottom Line
Use extended hours trading when the timing of a trade matters more to you than the execution conditions available during the regular session.
Before placing an order, check your broker's trading hours, eligible securities, order types, cancellation rules, and treatment of unfilled orders. A limit order can help control the price, but it cannot guarantee that your trade will execute.