When Musk first disclosed the stake, he used a 13G filing, which is typically reserved for passive investors. Musk acquired his Twitter stake on March 14, according to the filing. Shareholders who are hoping to hold a board position or otherwise change the company are typically required to file a longer, more in-depth form known as 13D within 10 days of buying at least a 5% stake.
New details in the 13D filing reveal that Musk made a series of cash purchases of Twitter stock between January 31 and April 1. The purchases ranged from as low as $32.80 per share to as high as $40.30 per share.
The move follows his appointment to the social media giant's board of directors.
Musk, who is now Twitter's largest stockholder with 73,115,038 shares, has had Wall Street buzzing over his potential next steps for the company's long-term strategy, with speculation ranging from an all-out buyout of the platform to doing nothing at all.
He has previously been critical of the platform's approach to free speech, going as far as floating the possibility of making a rival to Twitter. He has also been critical of Twitter CEO Parag Agrawal, comparing the executive to Joseph Stalin, the former leader of the Soviet Union.
Though Musk's long-term intentions for Twitter remain unclear, the filing emphasizes that he is not allowed to own more than 14.9% of Twitter's stock while serving on the board or for 90 days after. His term is set to expire at Twitter’s 2024 annual meeting.
Wedbush Securities analyst Dan Ives said in a note to clients on Tuesday that Musk's involvement with Twitter could "lead to a host of strategic initiatives which could include a range of near-term and long-term possibilities out of the gates for the company still struggling in a social media arms race."
Meanwhile, Bernstein analysts Mark Shmulik and Toni Sacconaghi Jr. believe Musk's interest is "mainly personal" and nothing more than a "potential distraction."
"We view the interest as a potential distraction for Musk and TSLA shareholders, given that Musk is arguably already overcommitted, and his fervor for the topic of censorship/free speech is high," they wrote in a note to clients on Tuesday.
Musk has teased that "significant improvements" will be coming to the platform in the coming months.
On Tuesday, Twitter revealed it has been working on an edit button since last year and has kicked off testing with users of its Blue subscription service. The idea was teased a day earlier in a poll put out by Musk seeking input from his more than 80 million followers.
The latest move comes amid an ongoing legal dispute with the SEC, in which the Tesla executive is trying to throw out a 2018 agreement with the regulator requiring him to obtain pre-approval for his tweets about the company.
Musk could potentially draw additional SEC scrutiny after he appears to have waited 21 days after March 14 to disclose his Twitter stake. If the SEC determined that Musk violated the disclosure rule, he could be hit with a financial penalty, which are historically pretty small, around $100,000. Musk is worth an estimated $288 billion, according to the Bloomberg Billionaires Index.
FOX Business' Megan Henney contributed to this report.