https://phys.org/news/2018-12-tesla-ceo-elon-musk-taunts.html

Musk had to resign as Tesla chairman under a September arrangement with the SEC to settle fraud charges stemming from a tweet in which he said he planned to take the firm private and already had the financing to do it.

That caused a brief spike in Tesla's share price, leading so-called short-sellers, who have been betting on the stock crashing for years, to lose millions.