After-Hours Trading - AHT
Trading after regular trading hours on the major exchanges.
Also known as the "after-hours market".
Taobiz explains After-Hours Trading - AHT
This was once reserved for institutional investors, but now individuals may also trade after hours. Participation by market makers and electronic communication networks (ECNs) is voluntary and, as a result, this kind of trading may offer less liquidity than that done during normal hours of trading. If you are trading in pre-market or after-hours trading, you should always use a limit order.