GameStop and AMC stocks have experienced a significant increase after a social media presence known as 'Roaring Kitty' resurfaced. The resurgence of 'Roaring Kitty' has sparked a rally in these so-called meme stocks, with some outlets reporting increases of over 70% for GameStop and 80% for AMC. However, there are also reports of GameStop's stock crashing after the company reported weak sales, suggesting uncertainty in the market.