Ann: Results of Share Purchase Plan, page-186

If you bought the shares in your personal name - not a busness - then any capital gain will simply be added to your taxable income. If held for less than 12 months the full gain is added - so if you're on the highest marginal rate you'll effectively pay 47% tax (45% plus medicare levy 2%). If you hold for over 12 months you'll get a 50% discount on the gain - so effective tax of 23.5% if on the highest marginal rate.

Now you can really complicate things and start a company to trade - no CGT discount though - and it looks good at 1st with a company tax rate of 25% (just been reduced this financial year from 26%) if your turnover is less than $50m. The trouble with this approach is when you want to buy your Lambo, you need to declare a dividend, which will become personal income and taxed at the 47% rate (minus the 25% company tax you've already been slugged with) so there's no getting around the tax unless you keep the money in the business. No Lambo though. And for the ppl saying you can buy a Lambo through the business, even assuming the ATO would allow this, the fringe benefits tax will kill you.

And I've use the 'Lambo' to represent any discretionary spending from profits.

For people near retirement age a SMSF is a great way to invest/trade - and can actually be done with zero tax if at the preservation age - for this definitely seek advice from a good accountant!