GameStop and AMC Entertainment shares active again premarket

The group of "meme" stocks, led by videogame retailer GameStop Corp.that have been volatile in recent weeks as investors on a Reddit subgroup have egged each other on, were active again in premarket trade Monday. GameStop shares were up 5% premarket, while shares of AMC Entertainment Holdings Inc. the world's biggest cinema chain, were up 12%. BlackBerry Ltd was up 3.8%, and Naked Brand Group Ltd. was up 9.5%. Koss Corp. a maker of headphones, was up 2.9%.

GameStop shares have gained 440% in the year to date, as investors on Reddit's WallStreetBets platform sought to punish short sellers who had driven short interest in the stock to 140% by buying the stock and creating a short squeeze.