Can you change your mind before you get a 1099B? Say I chose LIFO as my default and I sell some ABC stock in January for a short term gain while still holding on to some stock in ABC that are long term holdings. I figured I’d probably take more short term losses the rest of the year. However, my subsequent trading from Feb through Nov work out in such a way that my realized short term losses in that time have been offset by short term gains so that if my Jan trade had been FIFO, my total capital gains tax bill would be lower.
