Premarket and after-hours trading: how extended sessions work
The regular trading session on the major US stock exchanges runs from 9:30 a.m. to 4:00 p.m. Eastern Time on trading days. But trades also happen before and after those hours. These periods are called extended-hours trading, and they work differently from the main session.
When extended hours happen
The premarket session takes place before the 9:30 a.m. open, and the after-hours session follows the 4:00 p.m. close. Exact times depend on the trading venue and on your broker: some brokers offer premarket trading from as early as 4:00 a.m. ET and after-hours trading until 8:00 p.m. ET, while others offer shorter windows or none at all. Some venues and brokers have announced or launched even longer sessions, so check what your own broker supports.
Why it matters
Many companies release quarterly earnings and other major news outside regular hours. That is why you may see a stock move sharply “after the bell” or in the premarket, before most investors can react during the regular session.
The risks brokers must disclose
FINRA Rule 2265 requires brokerage firms to give customers a risk disclosure before letting them trade in extended hours. The risks it lists are worth knowing before you place an order:
- Lower liquidity. Fewer orders are available, so an order may be only partly filled, or not filled at all.
- Higher volatility. Prices can swing more than during the regular session.
- Changing prices. Prices in extended hours may not match the closing price or the next morning’s opening price.
- Unlinked markets. Prices on one extended-hours trading system may differ from those on another system trading the same stock.
- News announcements. News released during these sessions, combined with thin trading, can have an exaggerated and short-lived effect on prices.
- Wider spreads. The gap between the bid and the ask is often larger.
Order types in extended hours
Many brokers accept only limit orders outside regular hours. An order placed for one session may not carry over to the next, so read your broker’s rules on when orders expire.
Reading premarket moves
A large premarket move often reflects a small number of trades. It shows how some participants reacted to news, not necessarily where the stock will trade once the full market opens. Volume figures help: a move on very light volume is a weaker signal than the same move on heavy volume.
Key points
- Regular session: 9:30 a.m. – 4:00 p.m. ET. Extended-hours windows depend on your broker.
- Less liquidity and wider spreads are the norm outside regular hours.
- Use limit orders and check how long they stay active.
This article is general information, not investment advice. It does not consider your personal situation. Consider speaking with a licensed financial professional before making investment decisions.
