US Pre Market - 4:00Am To 9:30Am
Why Us stock market require this kind of long sessions for Pre market ?
& ya they have also a Post market session at 4:00 pm To 8:pm
What kind of system is this? 
@nithin sir can you explain this??
Any one can explain this…?
I think it is because global traders will or want to participate in US markets so they have extended sessions. It allows people from other countries to transact in their own standard day hours to an extent. Another reason could be it will also help participants to cover the risks arising due to events happening outside of trading hours. Said that still they won’t be liquid enough compared to normal trading hours.