Twitter shares fell 6 percent Wednesday as CEO Jack Dorsey testified before the Senate Intelligence Committee on meddling in the 2016 U.S. election.
Dorsey testified alongside Facebook COO Sheryl Sandberg about election meddling and abuse on their platforms. Google was also invited to testify, but the tech giant declined to send its CEO or parent company Alphabet's CEO.
Twitter's stock fell 1 percent Wednesday before the committee hearing began. Other tech stocks were also down on Wednesday.
President Donald Trump and other prominent Republicans have accused Twitter, Facebook and Google of political bias in recent months, with frustrations intensifying in recent weeks. Trump last week said social platforms are "treading on very, very troubled territory and they have to be careful."
Midday Wednesday, the Justice Department said Attorney General Jeff Sessions will meet with state attorneys general later this month to discuss concerns that tech companies "may be hurting competition and intentionally stifling the free exchange of ideas on their platforms."