This is just my opinion:
The way people were valuing Tesla is a massively valuable stock with a high potential of blowing up.
From the looks of things, Tesla has crossed into prolonged profitability. It's not a huge increase in revenue, but it is a big decrease in the chance of bankruptcy. Additionally, because Tesla can self fund and doesn't have to rely on the markets to raise money, they don't have to care very much about short sellers driving the price down.
The bull case (robo-taxis, etc.) is still there, but the chance of Tesla going bankrupt is much lower than 1 year ago, so the stock has shot up.
