New York CNN  —  Roaring Kitty, the former trader legally known as Keith Gill who helped stoke the meme stock frenzy in 2021, is back online. GameStop shares surged 71.8% on Monday after the account run by Gill shared a meme on X, marking its first post in three years. The shares skyrocketed by more than 110% earlier and were halted for volatility several times on Monday morning. The image depicts a man leaning forward in a chair with a video game console in hand. GameStop had posted the same cartoon in February, but with a red arrow and chair. In Gill’s cartoon, they are blue. The meme is interpreted to convey, “when things get serious,” according to Know Your Meme. Gill did not immediately respond to CNN’s request for comment. Gill, who goes by “Deepf—-ingvalue” on Reddit, was one of the leading forces on the WallStreetBets subreddit that drove eye-popping returns in GameStop’s stock after targeting short-sellers, who aim to turn profits on a stock by borrowing shares, selling them and returning them after purchasing them at a lower price. Traders also sent other stocks soaring, including AMC Entertainment and Bed Bath & Beyond, now collectively known as meme stocks, or shares of companies with a cult following that see wide swings based on their popularity among trader communities on social media rather than their fundamentals. Gill described himself as a casual daytime trader in testimony during a 2021 Congressional hearing on the GameStop mania. He has said he did not set out to help stoke the GameStop frenzy and instead believed that the stock was an attractive opportunity for investors. “The idea that I used social media to promote GameStop stock to unwitting investors is preposterous,” Gill said in written testimony. “I was abundantly clear that my channel was for educational purposes only. … Whether other individual investors bought the stock was irrelevant to my thesis.”