(Reuters) -GameStop shares surged more than 70% premarket on Monday after "Roaring Kitty" Keith Gill, the stocks influencer behind the 2021 retail trading frenzy, returned to Reddit with a post showing a $116 million bet on the embattled videogame retailer.

Roughly $390 million worth of GameStop shares had changed hands by 5:53 a.m. ET (0953 GMT), more than the $343 million in Wall Street favourite Nvidia , according to LSEG data.

It was the first post in three years from Gill's Reddit account, where screenshots of his bullish GameStop trades had in 2021 triggered a rush of demand for "meme stocks" - often companies with weak fundamentals that gained a cult-like following through social media hype.

The screenshot posted on Sunday showed a GameStop holding of 5 million, or 1.8% of its publicly available stock. It also showed $65.7 million worth of GameStop call options, typically bought to express a bullish view, expiring on June 21 at a strike price of $20.

The stock closed at $23 on Friday, up about 33% since Gill began sharing cryptic posts and memes from his "Roaring Kitty" account on X.com in May, sparking speculation over whether he would resume sharing his trades online after the hiatus.

"Keith Gill is putting his money where his tweets are, and some investors are clearly following his lead and rekindling interest in meme stocks," said Ben Laidler, global markets strategist at digital brokerage eToro.

GameStop was trending no. 1 on investor-focused social media platform stockstwits.com, indicating increased chatter among individual traders, while fellow meme stock AMC added 26%. Tupperware, SunPower Corp and U.S.-listed shares of BlackBerry rose between 6% and 13%.

Monday's surge also put GameStop short sellers on track to rack up nearly $1 billion in paper losses, according to data and analytics firm Ortex Technologies.

GameStop has been grappling with slowing sales as its core business of selling new and pre-owned videogame disks takes a hit from consumers moving to downloading games digitally or streaming.

Reuters could not verify the screenshot and Gill did not respond to a request for comment on Reddit or email.

Reddit shares jumped 5.6%, while retail trader-focused brokerage Robinhood gained 3.3%.

Gill's last post from April 2021, titled "final update", showed a holding of 200,000 GameStop shares worth $30.9 million.

(Reporting by Medha Singh and Amanda Cooper; Editing by Varun H K and Devika Syamnath)