IMHO, because of the number of your share transactions, the ATO...

IMHO, because of the number of your share transactions, the ATO will classify you as a Trader. I am uncertain as to whether you can claim past losses that have NOT been previously declared on your tax return, but that aspect is is certainly worth discussing with the ATO. You can certainly claim any future losses once if you are classified as a trader by the ATO.

You can, of course, distinguish between those shares bought for the short term and those bought for the long term, the latter being subject to CGT.

Please NOTE this is NOT professional advice.