"Buy XTZ shares on today Sell next day for a profit or loss - Do...

"Buy XTZ shares on today
Sell next day for a profit or loss - Do they still count for Tax?"

Duminda, if you don't already own XTZ shares that you have held for a year and you sell XTZ shares, yes, you pay tax at the full rate. Of course you could sell anything really, Commsec don't care as long as there is money to cover the transaction a day later. So if you held shares you have owned for more than 1 year, than capital gains tax on half the capital gain applies.

As I said though, it is not a strategy I would recommend, as the trade is just as likely to go the other way. If you don't have money to cover, Commsec will sell whatever they want from your portfolio to cover and likely restrict your trading in the future.