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What is pre-market and after-hours trading?

In one line: Pre-market and after-hours are trading sessions for US stocks before the 9:30 am ET open and after the 4:00 pm ET close, usually with fewer buyers and sellers.

Trading glossary · Updated 2026-10-21

The usual times (ET)

Each broker sets its own windows. Some start later. Some now offer overnight trading on certain stocks. Check yours, and see our market hours tool.

Why prices move here

Many companies report earnings just before the open or just after the close. Big news often lands outside regular hours too.

So a stock can jump in after-hours on a report, then open with a Gap the next morning.

A simple example

A stock closes at $80.00. At 4:05 pm it reports earnings.

By 4:30 pm it's trading at $86. The Spread is $85.70 bid, $86.30 ask. That's 60 cents wide. In regular hours it might be 2 cents.

Next morning it opens at $83. Anyone who bought at $86.30 after hours is down $3.30 a share at the open. It could just as easily have gone the other way.

Why it matters

Fewer people trade in these sessions. That thin Liquidity means:

• Wider spreads.
• Bigger jumps on small orders.
• Prices that may not hold once the regular session starts.

A common mistake

Using a market order after hours. With a wide spread and few orders, a Market order could fill far from the last price. Many brokers only accept limit orders (see Limit order) in these sessions for this reason.

Also remember: many brokers' stop orders only work in regular hours. A stop won't protect you from an after-hours drop.

More in day trading for beginners.

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