I do believe that Tesla has a bright future in the industry, but their current market cap is just straight up ridiculous. Unlike any other tech giant, they will never be able to reap the kind of margins with their products (cars!) like a "normal" tech company can, and at some point the rest of the car industry will catch up. Also, Elon Musk is a walking time bomb in my opinion, eventually he'll go too far with one of his endeavors and possibly drag everything else down with him.