As of today, Tesla hit a market cap of 69 billion dollars.
This is the most recent milestone on the way to a stock price of $420 per share. These goals, to some extent, are light-hearted jokes amongst investors, greatly fueled by Elon Musk and his rampant Twitter meme-ing.
Tesla stock has been on an absolute bull run the past two weeks. Short interest has dropped heavily, likely contributing to the rise.