Hi Westmoon. You are allowed to buy shares one day and sell the next, as long as the sell covers the total cost of the buy. They will offset sell against buy both on the day of the buy and the day after. If your sell covers part of the buy, you need to make up the rest with funds in your account.
If you leave it two days before you make any sell, you need to cover it fully with funds in your savings account (CDIA). If you don't have the funds, they start charging both at the bank and at Comsec, and threatening to close your account.
