allowing "limited buys" of these companies starting Friday.The announcement came as the company tries to clamp down on an influx of inexperienced investors that has sparked volatility in the market.Share prices of GameStop, AMC Entertainment, as well as Bed Bath & Beyond and BlackBerry have spiked this week after retail investors, spurred by the online Reddit forum WallStreetBets, piled into the stocks.RELATED: GameStop stock frenzy: Robinhood, others limit trading, sparking lawsuit and Senate panel hearingGameStop stock has rocketed from below $20 earlier this month to close around $350 Wednesday as a volunteer army of investors on social media challenged major Wall Street firms who bet the stock would fall.The action was even wilder.