For Tesla, yesterday, it was robots; today, it's full self-driving (FSD).Tesla (TSLA 5.42%) stock has been on a bit of a roll this week. Shares jumped more than 4% yesterday and popped another 7% in Thursday morning trading. As of 10:45 a.m. ET, Tesla stock was still trading higher by 6.3%.It's not because Tesla said it was selling more cars. In fact, yesterday's jump came when CEO Elon Musk posted about robots, not cars. But today was more closely tied to its core electric vehicle (EV) business. More speci ...