Elon Musk said he is putting his bid to acquire Twitter on hold, weeks after agreeing to take the company private in a $44 billion deal.

“Twitter deal temporarily on hold pending details supporting calculation that spam/fake accounts do indeed represent less than 5% of users,” Musk tweeted on Friday.

The news sent Twitter shares down more than 20% in premarket trading.

In his tweet, Musk linked to a Reuters report that said Twitter had disclosed in a filing Monday that fake or spam accounts represented fewer than 5% of Twitter’s monetizable daily active users during the first quarter.

Musk had offered few details about his plans for the social media company, though he has often spoken out about bot accounts that promoted spam content. He also says the company has been too quick to remove accounts that violate its content-moderation rules.

Even as Musk has worked to secure financing for the takeover, speculation about whether the deal would go through has been swirling since Twitter’s board agreed to the offer on April 26.

On Tuesday, Musk made headlines by saying he would allow former President Donald Trump to return to Twitter once the takeover was complete. Trump’s account was permanently removed after his followers’ attack on the US Capitol on January 6, 2021.