Elon Musk has pegged his $44-billion deal for Twitter Inc.
Musk cited pending details in support of calculation that spam and fake accounts indeed represent less than 5% of users.
Shares of the social media company fell 17.7% to $37.10 in premarket trading.
That represents their lowest level since Musk disclosed his stake in the company in early April and made an offer to take it private for $54.20 per share.
Twitter had earlier this month estimated that false or spam accounts represented fewer than 5% of its monetizable daily active users during the first quarter.
Musk has said he wants Twitter’s algorithm to prioritize tweets to be public and was against too much power on the service to corporations that advertise.
Earlier this week, he said he would reverse Twitter’s ban on former U.S. President Donald Trump when he buys the social media platform.