During market pre-open period, you can
place order, cancel order, reduce quantity, yet no increase in quantity;
you can see other people's order in terms of price and volumn;
no stoke trading in this period.
:)
Any other questions, you can contact my friend Wenhui @ [email protected]. He is a broker in CIMB-GK and I am sure he will be happy to provide u with good service.