best guide is here:...

best guide is here: https://www.ato.gov.au/General/Capi...ng-as-investor-or-share-trading-as-business-/

if you actually carry on a business of share trading & wish to report your tax that way, you fill out the Business & Professional Items (which is the 3rd section of the old Tax Pack booklets & forms) :

https://www.ato.gov.au/Forms/Business-and-professional-items-2017/

it used to look like this: http://www.accountantsdesktop.com.au/wp-content/uploads/2012/08/ReturnBusProfItems.pdf

but now, you just use 'MyTax', on-line: https://www.ato.gov.au/Individuals/Lodging-your-tax-return/Lodge-online/

i became a 'Business' for the 2009 year because i got hammered in the GFC and would have had a large CGT tax bill for 2008 if I did not change from CGT to a business (i amended my 2007 tax return from CGT to a business)