Twitter is cleaning up its platform and taking down more fake accounts than ever, according to The Washington Post, but the stock still tanked on what appears to be concern around user growth.

The company's shares fell as much as 9.7 percent Monday, to a low of $42.08, after the Friday evening report that Twitter is suspending more than 1 million accounts a day. The newspaper, citing an unnamed source, reported the unprecedented takedown rate could impact user metrics for the second quarter.

Chief Financial Officer Ned Segal clarified in a tweet Monday "most accounts we remove are not included in our reported metrics as they have not been active on the platform for 30 days or more, or we catch them at sign up and they are never counted."

He added, "If we removed 70M accounts from our reported metrics, you would hear directly from us. This article reflects us getting better at improving the health of the service. Look forward to talking more on our earnings call July 27!"

The company's stock pared some losses immediately following the tweets from Segal, rebounding above $44 and closing just 5 percent down at $44.10.

"In our view, there is some risk of reported user volatility due to fake and automated account removal in the near term, though the continued purge of fake accounts is clear progress for the longer-term health of the platform," analysts for Stifel wrote in a note Monday.

Twitter's dip makes for the stock's worst day since March 27 when it shed 12 percent. The shares are still up nearly 85 percent in 2018 and more than 140 percent in the past 12 months.