commsec rule

trust2004

just wondering if i buy a share today, but sell it tomorrow, do i need to put money in the account.

Brother

should be yes, settlement house will collect the money, this is to prevent空麻袋背米。
if you want to do short term trading and not have the full amount capital, you should try CFD. because it offers cheaper brokerage,

Devil_Star

The answer is yes and no. Brokers will need you to provide them securities before they put through the orders for them. However these required securities are not limited to cash. The other popular types are "quality" shares and funds which are valued less than their mark-to-market value, i.e. with a margin discount.

Find details in my q&a post and find out how to do 空手套白狼。