Pre-Open Order Fills

For those that trade stocks - why is it some orders are filled before exchange opens, whose orders and why? Joe Bloggs cant do same why?

 

any body know answer please

 

i dont trade outside of regular hours, so im not the best person to answer this... but i think some ECNs open before the market does, you might have to rout your orders directly to one that is open.

 

Anyone can do it. It's called pre-market trading. Look it up.

 

Thanks - If anyone is allowed then I wonder why some of stock trading friends are actually not allowed to trade outside regular hours - their accounts are blocked to trade outside normal hours