what is after hours trading 
the term after hours trading refers to trading activity that starts at 4 p m u s eastern time after the major u s stock exchanges close the after hours trading session can run as late as 8 p m though volume typically thins out much earlier in the session after hours trading is conducted through electronic communication networks ecns although there are some key advantages of trading when the market closes traders should be mindful of all the risks associated with this period understanding after hours tradingafter hours trading generally refers to trading that takes place after normal market hours and up until about 8 pm premarket trading refers to trading that takes place before the start of normal market hours generally from 7 a m until 9 25 a m together after hours trading and premarket trading are referred to as extended hours trading the precise times of extended hours trading can depend on the ecn an investor uses or the financial institution where they place their orders for instance wells fargo allows after hours trading from 4 05 p m et until just 5 p m 1traders and investors engage in after hours trading for a variety of reasons they may prefer trading with fewer market participants or their schedules may require it they may want to take positions as a result of news that breaks after the close of the stock exchange or they may want to close out a position before they leave on vacation electronic markets used in after hours trading automatically attempt to match up buy and sell orders if they can do so trades are completed if they can t trades remain unfilled quotes provided are limited to those available through the electronic market used investors may have access to other participating ecns but it isn t guaranteed after hours trading scheduleafter hours trading may occur during two periods after hours after market close but on the same calendar day or pre market after market close but on the subsequent calendar day before the next opening pre market trading often occurs between 4 00 a m et and 9 30 a m et after hours trading often occurs between 4 00 p m et and 8 00 p m et note that different exchanges may have varying hours and varying trade data posting times for example nasdaq pre trade data will be posted from 4 15 a m et to 7 30 a m et of the following day while after hours trades will be posted from 4 15 p m et to 3 30 p m et of the following day 2