does after hours trading affect opening price 
it certainly can since a great deal of trading may be taking place after hours prices of securities can change from their levels when the regular market previously closed can you actually trade after hours yes provided your brokerage authorizes you to do so you ll first want to make sure you clearly understand how after hours trading works and the risks involved in it your brokerage may ask that you meet with a investment representative to make sure you know the difficulties posed by after hours and premarket trading 