GameStop Corp. shares skyrocketed on Monday, more than doubling in value after Keith Gill, the influential figure behind the 2021 meme-stock frenzy, posted a screenshot suggesting he holds a $116 million position in the company. This marked Gill's first major social media activity in three years, reigniting fervor among retail traders and sending shockwaves through the market.

Gill, known by his Reddit pseudonym "DeepF------Value" and his social media handle "Roaring Kitty," posted an image on June 2 that showcased his holdings of five million GameStop shares, purchased at $21.27 each. Additionally, the screenshot indicated he held 120,000 call options valued at $65.7 million, set to expire on June 21. The authenticity of the post remains unverified, but its impact was immediate and significant.

GameStop shares surged as much as 105% in premarket trading on Monday, though the gains were somewhat pared later in the session. If the premarket momentum is sustained, the stock could add approximately $8 billion to its market capitalization. The rally also buoyed other stocks popular among retail traders, with AMC Entertainment Holdings Inc. rising by 36% and gains seen in SunPower Corp., Beyond Meat Inc., and BlackBerry Ltd.

Gill also shared a cryptic image of an UNO reverse card on social media platform X, formerly known as Twitter. The post, interpreted by many as a signal of his re-engagement with the market, garnered around 5.5 million views within nine hours of its publication.

"Recent renewed interest in meme stocks, coming as the main US indices struggle to make new highs, is a sign of excessive exuberance and is more likely a negative portent given the rising headwinds in the markets," commented Robert Lea, an analyst at Bloomberg Intelligence.

Gill had been largely absent from social media since he galvanized a wave of day-traders on Reddit in 2021 to buy GameStop stock, countering short-sellers and propelling the stock to unprecedented heights. The company's shares famously surged over 2,000% during the initial meme-stock boom, bringing widespread attention to the phenomenon.

In mid-May, Gill hinted at his return to the market with a subtle image of a video gamer leaning in, which had already sparked a doubling of GameStop shares. However, the stock had fallen more than 50% in the interim two-day rally until his recent post reignited enthusiasm.

Gill's latest post appeared on the r/Superstonk subreddit, a forum dedicated to theoretical discussions about GameStop stock. This contrasts with his previous activity on the r/WallStreetBets subreddit, where he had originally posted during the height of the meme-stock mania.

The resurgence of interest in GameStop and other meme stocks reflects the enduring influence of retail traders, despite broader market uncertainties. "The renewed attention to these stocks indicates that retail traders still have significant market-moving power, even amidst challenging economic conditions," noted Lea.

GameStop, which has struggled with its transition from brick-and-mortar stores to online gaming, recently leveraged a similar rally in May to raise over $900 million through a stock sale. Investors continue to place their hopes on CEO Ryan Cohen's vision to reinvent the company.

Gill's role in the 2021 meme-stock episode had led to regulatory scrutiny and a series of congressional hearings focused on broker practices and the gamification of retail trading. Brokerages, including Robinhood, had restricted trading in GameStop at the peak of the frenzy due to extreme volatility and clearinghouse margin issues.