Elon Musk has offered to buy Twitter (TWTR) and "transform" it.
Musk has offered to buy all of Twitter's shares for $54.20 each, valuing the company at $43.4 billion.
Musk said in the SEC filing that if the cash offer was not accepted, he would have to reconsider his shareholder position.
According to the filing, Musk made an offer late Wednesday night.
"I invested in Twitter because I believe free speech is a societal imperative for a functioning democracy," he wrote in a letter to Twitter.
"But since investing, I've realised the company won't thrive or meet the societal imperative in its current form. Twitter must become a private company "he says.
The letter was addressed to Twitter board chair Bret Taylor, not CEO Parag Agrawal, who took over last fall. It ends: "Twitter has huge potential. I'll open it."
Musk's false tweet about taking Tesla private got him in trouble with the SEC.
He had to relinquish his chairmanship of Tesla and allow other executives to review his material information tweets.
The price he suggested for Twitter at the time, $420 per share, emphasised April 20, the unofficial marijuana holiday. Twitter's $54.20 per share offer includes "4.20."