Tesla shares dropped more than 13 percent in after-hours trading Thursday after the Securities and Exchange Commission filed securities fraud charges against CEO Elon Musk .

The SEC alleges in a complaint filed against the CEO that Musk lied when he tweeted on August 7 that he had “funding secured” for a private takeover of the company at $420 per share. The SEC complaint, filed in federal district court in the Southern District of New York, said the tweets were “false and misleading.”

The SEC, which said the tweets led to “significant market disruption,” is seeking civil penalties without noting an amount and to bar Musk from serving as an officer or director of a public company.

Am considering taking Tesla private at $420. Funding secured. — Elon Musk (@elonmusk) August 7, 2018

Musk sent a statement Thursday afternoon calling it an unjustified action.

In August, Musk sent a tweet that he had secured funding and was considering taking Tesla private. The tweet wasn’t warmly embraced by the Tesla board or many shareholders and it’s what prompted the SEC to investigate.

Several weeks later the company posted a blog announcing that Tesla will remain a public company.