AVZ run to 50, page-270

I'm not an accountant, but I believe that is not correct, from ATO website:

"The point at which you make a capital gain or loss is usually when you enter into the contract for disposal, not when you settle. "

CGT is applied to your capital gain, not "the money you receive", there's no such concept of "in play". You have to be careful, if you trade a LOT in one year and make a tons of money that you keep "re investing", you can actually quickly rack up a hefty tax bill, even if you have no money in any bank account to pay that tax. Every time you sell at a profit you are making a capital gain which will be subject to CGT.

Worst case scenario is, you make a fortune trading and invest it all in some stocks that then sink badly, say GFC2.0 hits. Well I believe you will still be liable for the CGT on all your prior gains, but you can't claim any "loss" until you sell out, which you might not want to do, and there is a law which prevents you from just selling out to claim the loss and buying straight back in.

Lot's of "gotchas," there's plenty of reading here

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

And you should definitely speak to an accountant.