What happens if you buy shares of the same company at different stages and then sell some of your holdings? How do you know which shares you have sold? Example X buys 500 ANZ shares on 1 Jan 2012 for $20 each and 500 ANZ shares on 01 Feb 2015 for $22 each. On 19 Dec 2016 he sells 500 ANZ shares for $24 each. The CGT consequences will be different for each lot, so how do we know which lot he as sold? If the shares can be distinguished then it is possible to work out which lot has been sold. If they cannot be distinguished then the ATO will accept the 'first in first out' rule. this means X would be considered to have sold the first lot of 500 shares - the ones he acquired for $20 each.