GameStop shares jump more than 40% as 'Roaring Kitty' schedules YouTube livestream for Friday

Shares of GameStop shot to session highs Thursday after meme stock leader "Roaring Kitty" scheduled a livestream on YouTube, which would be his first one in almost four years.

Roaring Kitty, whose real name is Keith Gill, set the time for his live chat at noon Friday, which traders speculated would be a bullish discussion about his massive GameStop stake. The investor hosted three-hour livestreams in August 2020 explaining his investing thesis behind his favorite brick-and-mortar video game retailer.

GameStop popped more than 47% higher to close at $46.55 per share. The stock hit a high of $47.50 during the session, in which trading was briefly halted for volatility. The stock has more than doubled so far this week.

GameStop, 1-day

There were already more than 10,000 people waiting in the livestream and countless comments were flowing through the chat box.

Gill, who goes by DeepF------Value on Reddit, resurfaced online recently more than three years after sparking the historic trading mania in 2021 that burned short-selling hedge funds. Last Sunday, he started posting screenshots of his E-trade portfolio holding five million shares of GameStop common shares and 120,000 call options. Combined, they have a market value of at least $200 million now. He seemed to have held onto his positions as of Thursday night.

Those call options, if exercised, could bring Gill's stake in GameStop to 17 million shares. If the stock returns to its May high of $64.83 per share, Gill's position would then be worth more than $1 billion.

Gill had paused posting updates during the week after The Wall Street Journal reported that Morgan Stanley's E-Trade broker was considering booting him because of the worry that what he was doing could amount to market manipulation. 

CNBC has not independently verified Gill's holdings.

The investor is a former marketer for Massachusetts Mutual Life Insurance. The mania in 2021 led to a series of congressional hearings, featuring Gill, around brokers' practices and gamifying retail trading.