https://techcrunch.com/2018/08/08/the-sec-wants-tesla-to-explain-elons-420-tweet/

Elon Musk, billionaire founder of Tesla, startled the Twittersphere yesterday by announcing he wanted to take the company private at the price of $420 per share. While some speculated the tweet was a joke or a marijuana reference, others took to the market. The tweet sent the stock soaring up 11 percent, causing a halt in trade for a portion of the day.

Now, the Securities and Exchange Commission is looking into the matter.