"to answer your question, the date acquired must be before or on the date sold."
Thanks! That's what I was looking for.
As an aside, adding to my confusion, I found definitions for a highest-cost-first-out (HIFO) method that let you choose the highest cost share as your cost basis regardless of the purchase date of that share.
So it didn't seem too far of a stretch to declare that for LIFO, you could choose the last purchase you made during the tax year as your "Last In", regardless of if your date of sale occurred earlier. (which in my example, would have let me use my December purchase as my cost basis for my March sale). And really, I still can't find anything concrete to contradict this.
So if what you say is true, then while indeed "LIFO just means you are going in the opposite order [of FIFO]", there apparently is also the caveat of "the date acquired must be before or on the date sold."
I'll probably stick with FIFO just to avoid any problems, but I am genuinely curious about an answer.
Thanks to everyone who replied 🙂
