After hours
Family VII · Market & styles
Not to be confused with market hours, trading hours.
After hours is the period when a market is open for trading outside its regular session. In equities, this usually means pre-market and post-market sessions on electronic communication networks (ECNs) or alternative trading systems, while futures and foreign exchange trade nearly around the clock. Liquidity is generally lower, spreads wider and price swings sharper than during regular hours, and the exact times, eligible instruments and order types are set by each exchange or venue.
Session boundaries and access
Regular session hours are fixed by the exchange and vary by country and asset class. After-hours sessions extend before and after those hours, but they are not uniform: some venues open pre-market at a set time, others allow only limit orders, and many brokers restrict certain order types or require separate permissions. Settlement, reporting and circuit-breaker rules may also differ from the regular session.
Because participation is lower, quotes can be stale and the difference between the best bid and best offer widens. Trades in the after-hours session may not be included in the official closing price or opening price of the next regular session.
Worked example: after-hours fill versus regular session
An investor wants to sell 500 shares of a stock that closed the regular session at $50.00. In the after-hours session, the best bid is $49.60 for 200 shares and $49.20 for the next 300 shares. The average fill price is calculated below.
The average fill of $49.36 is $0.64 below the regular-session close of $50.00, reflecting the wider spread and thinner book typical of after-hours trading.
Risks and variations
After-hours trading carries risks that are less pronounced in the regular session: lower liquidity, greater price volatility, and the possibility that news released after the close is reflected in prices before the next official open. Rules on short selling, order types, and price bands during after-hours sessions differ by regulator and exchange, so the same instrument may behave differently on different venues.
Investors should check their broker's specific after-hours policy, including eligible order types, cut-off times and whether extended-hours trades are covered by the same investor protections as regular-session trades.
Often confused with
- market hours
- Market hours are the official regular session times set by an exchange, whereas after hours is any trading outside those times; the visible sign is that market hours have a fixed opening and closing bell, while after hours has no single universal schedule.
- trading hours
- Trading hours is a broad term for all times a venue is open, including regular and extended sessions, while after hours is specifically the extended session outside the regular one; the visible sign is that trading hours can refer to the whole day, whereas after hours is only the pre-market or post-market portion.