That's a good point. Still, I can see reasons for raising it's perceived value over last year. A year ago, Falcon Heavy still hadn't launched. Will that happen

That's a good point. Still, I can see reasons for raising it's perceived value over last year. A year ago, Falcon Heavy still hadn't launched. Will that happen in 2018? Ever? We didn't know. A year ago, we were still barely a year since the 2016 pad explosion- is this going to happen again? How often? What if it happens tomorrow? And most importantly, we've doubled (ish?) the number of landings. With more data, we've got a better estimate on the expected future success rate. SpaceX is becoming a less risky investment. There was always a valuation hit because of that risk.