You can actually have money in the account and they (Commsec) wont let you place an order if you have been trading multiples of the cash in your account. For example, if I have $5,000 in my account and do 5 trades over the day of $5000, then I have traded $25,000 and wont be able to trade the next day as it exceeds the daily limit of 2 x cash + $7,500, which is $17,500.
