@SLYKTAX sorry for the confusion. What I meant is that when you sell the stock(s) you will have to tell the broker which batch you are selling from. You can also choose how many from each block if you want to do that. Once that is done the basis of the stocks is frozen. Thus when you file your return, you recognize the gain/loss and the holding period, based on what you sold through the broker.
Does this make sense ?
