A British trading platform on Saturday announced it will block new trades of two U.S. stocks, GameStop and AMC Entertainment. “Due to extreme volatility, and to prioritise the service we give our existing clients, we are not allowing any new positions to be opened on the US stocks GameStop and AMC Entertainment,” IG Group said in a tweet on Saturday. “These restrictions apply to all IG accounts, and will be reviewed regularly. You will still be able to close any open positions that you have in these stocks. Any orders that you have already placed on these two stocks will remain,” The BBC quoted the company as saying. The company is the latest trading platform announcing restrictions following a surge in volumes in recent days stemming from calls on social media by individual investors to trade stocks like GameStop and AMC that were being heavily shorted by hedge funds. IG’s …