1MRX. In the hypothetical you put forward, if you held 500...

1MRX. In the hypothetical you put forward, if you held 500 shares for 12 months + bought another 500 shares of the same stock & then sold 500 shares a week later, the ASX & ATO always views the transaction as first on first off. In other words the 500 more recently bought are still held. The tax burden on the 500 sold is deemed to be at 15% unless your yearly earnings threshold has pushed your income into a higher tax bracket. If that were to be the case & as slick has suggested it would be be of benefit to start your own business as a new entity for trading to benefit tax wise. Best to do some ATO research if you are in that financial position & if you are, you would more than likely have an accountant that can advise you.