If you bought BTC to buy pizza, and you spend the bitcoin for personal goods or services, and you bought less than $10,000 worth, you could be exempt from capital gains tax. See:
https://www.ato.gov.au/General/Gen/...age=1#Using_bitcoin_for_personal_transactions Do check with your accountant though. Selling them for cash might not count depending on what you do with the cash.
All the more reason we need more merchants to accept bitcoin, given how many people would be sitting on potential capital gains.