Affinion Discussion, page-314

https://www.ato.gov.au/General/Capital-gains-tax/Selling-an-asset-and-other--CGT-events-/

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If you dispose of a CGT asset, the CGT event usually happens when you enter into the contract for disposal. (In the case of real estate, for example, the CGT event generally occurs when you enter into the contract – that is, the date on the contract, not when you settle.) If there is no contract, the CGT event generally happens when you stop being the asset's owner. .."​

https://www.ato.gov.au/General/Capital-gains-tax/Shares-and-units/

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Shares in a company or units in a unit trust (including a managed fund) are treated in the same way as any other CGT asset. CGT applies to capital gains on shares or units when a CGT event happens, such as when you sell them (unless you acquired them before CGT started on 20 September 1985). .."​

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