Amid the flurry of speculative activity in GameStop, brokers took steps to restrict the trading in GameStop stock and options and other related securities. In some cases, investors would only we able to sell their positions and not open new ones. Free-stock trading pioneer Robinhood and Interactive Brokers both took steps to curb the wild trading activity in heavily shorted names like GameStop, AMC Entertainment, Koss and more on Thursday. Shares of GameStock reversed course and slid quickly into negative territory as word of the trading restrictions spread. The stock, which traded above $500 at one point in ... (full story)