Your trading platform does not choose which parcel you sell....

Your trading platform does not choose which parcel you sell. Assuming you are not classified as a trader by the ATO (who are handled completely different and do not qualify for the GCT discount), you get to choose for each individual share when you do you your tax return each year (or your accountant chooses as the case may be). So if you buy three parcels and sell two during a financial year, you get to choose which two you sold.

It gets increasingly tricky with multiple parcels of different sizes across financial years keeping track of which ones you have told the taxman you have offloaded or kept, particularly with keeping track of which will qualify for the GCT discount. That is why some chose to simply report first in first out. Accountants will play around (on computers obviously) with which parcels they report as sold to get the best outcome for you, at the time, though if the stock skyrockets later it can potentially end up harming your GCT discount. Nothing is perfect. I try to concentrate on making gains, and let my accountant concentrate on minimizing my tax, otherwise I would go mad.

Note that the above does not apply to shares held in relation to qualifying for franking credits, which have an ATO ruling of last in first out when it comes to qualifying for the 45 day (actually a 47 day) rule. But that is a different story which obviously does not apply to PLS.

This is just my opinion (and I am not an accountant), and it is well worth DYOR (reading on the web at least, or even invest in a planning session with a good accountant) early on to get your head around the tax laws, because they can affect the way you invest and set up your trading accounts. It can all make a big difference to your after tax return, though many neglect it until its too late.

GL with it.