GameStop shares soared more than 70% in premarket trading on Monday after a new post from retail investor "Roaring Kitty." The screenshot posted on Sunday by Roaring Kitty, also known as Keith Gill, showed a GameStop holding of 5 million, or 1.8% of its publicly available stock. It also showed $65.7 million worth of GameStop call options, typically bought to express a bullish view, expiring on June 21 at a strike price of$20. Ticker Security Last Change Change % GME GAMESTOP CORP. 23.12+0.52 +2.29% And on ...