WASHINGTON (Reuters) - Texas Attorney General Ken Paxton issued 13 civil investigative demands on Friday to Robinhood, Discord, Citadel and other trading apps that put curbs on stock trading, his office said in a statement the day after those curbs stalled a rally in shares of GameStop. The CIDs, the civil equivalent of a subpoena, were sent following a week-long slugfest in which retail investors bid up shares of video game retailer GameStop and other out-of-favor companies, resulting in huge losses to big hedge funds that had shorted those stocks. On Thursday, GameStop shares fell after Robinhood and other trading apps imposed the limits, a move that angered many elected officials and prompted calls for action from regulators. “This apparent coordination between hedge funds, trading platforms, and web servers to shut down threats to their market dominance is shockingly unprecedented and wrong,” Paxton said in a statement. The CIDs were sent to Discord, Robinhood Financial, Robinhood Markets, Robinhood Securities, Interactive Brokers, TD Ameritrade, TD Bank, E-Trade, WeBull Financial, Public Holdings, M1 Holdings, Citadel Financial, and Apex Clearing Corporation, Paxton’s office said in a statement. (This story corrects headline to read ‘GameStop’)