On April 4, Twitter (TWTR  ) revealed in a tax filing that the world's richest man, Elon Musk, had purchased a 9.2% stake in the company, becoming its largest shareholder. Just a day after the purchase was reported, Twitter announced that the tech billionaire would be joining its board of directors. Less than a week later, the company announced that Musk will no longer be joining its board.

Musk, a fifty-year-old prolific Twitter user with more than 81 million followers and a net worth of $300 billion, began a posting spree after his board appointment was first announced last Tuesday. He said that he was planning to make "significant improvements to Twitter in coming months!"

He also asked Twitters users things like, "Is Twitter dying?" and made pointed suggestions for changes to the platform's verification, premium features, and advertising. He wrote that Twitter should remove ads entirely and that the company's San Francisco headquarters should be converted into a homeless shelter because "no one shows up anyway". It's worth noting that some of these Tweets have since been deleted.

A day after Musk's antagonistic posts, the company's CEO, Parag Agrawal, took to his own account, positing a statement and an announcement that "Elon has decided not to join our board".

"Here's what I can share about what happened," Agrawal's statement reads. "The board and I had many discussions about Elon joining the board, and with Elon directly... Elon's appointment to the board was to become officially effective 4/9, but Elon shared that same morning that he will no longer be joining the board. I believe this is for the best."

In the statement, Agrawal also says that the board had planned to bring Musk on as a company fiduciary, something that is required for all board members under corporate governance. A fiduciary must act in the best interests of the company and shareholders.

While Musk is no longer set to join Twitter's board, he will now once again be able to buy control of the company. Under his prior agreement with the company, his stake in Twitter was capped at 14.9%, and he was barred from staging a takeover. Without that agreement, Musk is once again free to continue purchasing Twitter stock.

Musk has been a volatile presence on Twitter for years. Along with his frequent digs at the social media platform and Tesla (TSLA  ) critics, Tesla CEO Elon Musk also ran into trouble with the U.S. Securities Exchange Commission (SEC) because of claims he made on Twitter regarding the automotive company.

According to the SEC, Musk falsely claimed that he had funding to take Tesla private in 2018, leading to a $40 million fine and an agreement to have all Twitter posts relating to Tesla approved by a lawyer prior to publishing. Musk recently contested this agreement, claiming that it is an infringement upon his First Amendment rights.