That tweet is at best an impulsive, reckless, perplexing action by a chief executive who should have known how to stay on the right side of securities law. At worst, it's an emotional attempt to fend off, possibly even cause direct financial loss to his many critics and short-sellers.
This doesn't look good for him. This is the key paragraph in the article that makes it serious:
> The subpoenas indicate senior SEC officials have authorized a formal investigation of the company, a step up from the initial inquiries the regulator made to Tesla last week. The SEC opens formal investigations when it thinks a violation of law has occurred and that a probe is justified given the nature of the suspected misconduct and the potential harm to investors.
Unless Elon can suddenly show he had credible funding secured - contrary to his own blog post of last week - this looks like a strong case for the SEC:
> “The release issued earlier Monday clearly raised at least as many questions as it hopes to answer. The probability that there will be an SEC enforcement action is, I think, quite high,” said Joseph Grundfest, a law professor at Stanford University and a former SEC commissioner.
> Other experts agreed. John Coffee, a securities and corporate law professor at Columbia University, said the SEC can credibly argue that Mr. Musk’s tweet last week, which caused Tesla’s stock price to jump 11% the day he posted it, didn’t give shareholders the full picture they needed.
> “This is a clear statement that he has nothing more than an expression of interest as opposed to a binding commitment,” Mr. Coffee said. “It will tell the SEC that they have a virtually open-and-shut case if they wish to sue.”
https://www.wsj.com/articles/musks-tweets-on-tesla-buyout-fa...
Besides the SEC, which can lead to both criminal and civil prosecution, there are also civil lawsuits filed in this case - three of them so far:
https://www.businessinsider.com/tesla-hit-with-new-lawsuit-a...