This is not meant as an insult but just to be sure we are talking apples to apples, when you say you lost or gained, did you sell the stock or is it just the loss or gain based on current value?

Also, what do you mean by “long term” and “short term.” Why is it that if you lose 12k you can only write off 3k? Is it because you only had 3k in capital gains so you only used a portion of the loss to offset gains or is there another reason?