Maybe a dumb question, say you have a holding of X company and you bought a parcel of shares at 80c (entry) and a parcel of shares at 54c and 50c. If you sold a portion of your holding does it sell off as an average, or do your oldest shares i.e. those bought at 80c get sold off first - in the instance where the stock price goes to 65c and you want to trim your holding?