It is literally in TR 2005/15, if you even bothered to read it.
or if it is too hard for you to understand then how about:
https://community.ato.gov.au/t5/Business-registration/Where-do-we-enter-CFD-trading-gain-or-losses-I-file-my-tax/td-p/87916
https://community.ato.gov.au/t5/Personal-tax-questions/CFD-taxation-on-gains-and-losses/td-p/4458
