Ocasio-Cortez said the move was "unacceptable," adding Congress needs to know more about Robinhood's decision "to block retail investors from purchasing stock while hedge funds are freely able to trade the stock as they see fit."

She said the House Financial Services Committee investigation should not be limited to Robingood but "should examine any retail services freezing stock purchases in the course of potential investigations - especially those allowing sales, but freezing purchases."

(Reporting by David Shepardson; editing by Doina Chiacu)