Musk has had feuds with regulators, critics and reporters, and questions remain about Tesla's production and manufacturing difficulties, long-term demand for its cars and uncertainty over funding.
The tweets are the latest example of a long string of weird outbursts from the billionaire tech mogul.
The announcement, made initially via Twitter Tuesday afternoon, stunned investors and sent Tesla's stock price soaring as much as 13 per cent.
Taking Tesla private would certainly qualify.
Musk's tweets, though, might present a bigger problem. He also said he intends to give Tesla's existing shareholders the option of retaining a stake in the company through a special fund, if they want. Musk has followed up with an offer for current stockholders to keep their shares and "go private" - without knowing further details on the company's board and governance structure.
Musk amplified this point Tuesday, saying on Twitter that going private "will be way smoother", end "negative propaganda from shorts" and benefit shareholders. Shares jumped in Tuesday trading following reports that the Saudi Arabian sovereign wealth fund took a $2 billion stake in the company earlier this year.
The SEC website explains that "Form 8-K is the "current report" companies must file with the SEC to announce major events that shareholders should know about".
Tesla's shares were up 6.5pc at $363.46.
It's also unclear what brought him to the $420-a-share figure - the number can be used as a slang term for marijuana.
"I believe Tesla considers Tweets as public disclosure".
Tesla is producing roughly 7,000 Model 3, Model S and Model X vehicles per week. This would enable you to still share in the growing value of the company that you have all worked so hard to build over time. He clashed with analysts on a contentious call after Tesla reported earnings three months ago. About an hour and 20 minutes after the Musk tweet, trading in Tesla stock was suspended because the company was expected to release news.
Tesla doesn't meet the typical profile of a company that can raise tens of billions of dollars of debt. That baseless tweet was quickly deleted and Musk apologized to the diver. "Pedo" is short for pedophile. I think he's serious.
While Musk has described himself as "half Democrat, half Repulican" in the past, it struck many as hypocritical that a green energy CEO would donate almost $40,000 (£30,700) to help keep in power a political party that has largely ignored or denied climate change.
"I can't believe this is something to bluff or make fun of".
Alexandra Olson reported from NY.
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