SAN FRANCISCO (AP) — Twitter’s largest investor, billionaire Elon Musk, is reversing course and will no longer join the company’s board of directors less than a week after being awarded a seat. 

Twitter CEO Parag Agrawal announced the news, which followed a weekend of Musk tweets suggesting changes to Twitter, including making the site ad-free. Nearly 90% of Twitter’s 2021 revenue came from ads.

“Elon’s appointment to the board was to become officially effective on 4/9, but Elon shared that same morning that he would not be joining the board,” Agrawal wrote in a reposted note originally sent to Tesla employees. “I believe this is for the best.”

Agrawal didn’t offer an explanation for Musk’s apparent decision. He said the board understood the risks of having Musk, who is now the company’s largest shareholder, as a member. But at the time it “believed having Elon as a fiduciary of the company, where he, like all board members, has to act in the best interests of the company and all our shareholders, was the best path forward,“ he wrote.

The rapidly evolving relationship between Musk and Twitter began exactly one week ago when regulatory filings revealed the mercurial billionaire had amassed a 9.2% stake in the social media platform. A later financial filing showed that Musk had been buying up the shares in almost daily batches starting Jan. 31. 

Twitter gave Musk a seat on the board on the condition that he not own more than 14.9 percent of the company’s outstanding stock, according to a regulatory filing.