You are able to take up to a $3000 loss per year, assuming your loss is sufficient. But, before that happens, it is counted against any capital gains you might have. So, out of your $13k loss, $1,200ish went to cover your cap gain and $3000 was the loss you could take on your 1040. If your cap gain had been $13,000, you would have had a $5 cap loss left over on your 1040.
