Galumay
I buy 10000 at $1. 1/2/2020
Then 10000 at $1.40 1/3/2020
Then sell 5500 30/6/2020
Whats my profit and what am I taxed on?
As per the ATO, you can choose what parcel to 'link' the sale with, or you can use a first in, first out approach. Either way you need to split the chosen parcel into 2, so 5500 & 4500 shares in your records.
Your profit will depend on your sale price and which parcel you choose to use for your cost base, you will be taxed on the capital gain resulting.
So, expanding your example,
10,000 at $1
10,000 at $1.40
sell 5500 at $2
if you use first parcel
5,500 sold, 4,500 left at $1
10,000 at $1.40
5500 sold for $2
profit of $11,000-$5500=$5500 - you will pay CGT on this less costs
if you use second parcel,
10,000 at $1
5,500 sold, 4,500 left at $1.40
5,500 sold for $2
profit of $11,000-$7,700=$3300 - as above.