The US Securities and Exchange Commission on Friday said it was "closely monitoring and evaluating the extreme price volatility of certain stocks," after a social media-fueled campaign sent shares of Gamestop and AMC soaring. "We will act to protect retail investors when the facts demonstrate abusive or manipulative trading activity that is prohibited by the federal securities laws," the Wall Street regulator said, after some platforms this week restricted trades of the surging stocks. cs/dw