The meme stock GameStop rallied again Monday on speculation that Keith Gill, the man who inspired 2021's epic short squeeze, could have a huge position in the video game retailer. Shares were last about 50% higher, trading above $34 apiece. Gill, known as Roaring Kitty on YouTube and X, reappeared Sunday night, posting a screenshot suggesting he holds 5 million shares and 120,000 call options in GameStop. Gill's recent return to social media has sparked buying frenzies among amateur traders, leading to a more than doubling GameStop's share price in May alone. GameStop took advantage of this rally by raising over $900 million in a stock sale.