The return of Roaring Kitty, the X account associated with internet celebrity trader Keith Gill, has lifted shares in GameStop to a two-year high. But even before this week's rally, the struggling videogame retailer was trading at 700 times expected earnings.

The social media company and retail brokerage could both see increased activity from a return of meme stock trading.

GameStop shares jumped more than 70% on Monday after trader Keith Gill, known online as "Roaring Kitty," returned with a social media post after being gone for four years.

GameStop's fundamentals remain unchanged, with declining revenue and a questionable valuation. Find out why GME stock is a speculative investment.