• Keith Gill, AKA Reddit's DeepF------Value, apparently lost more than $13 million on Tuesday alone from his GameStop bet as the shares dropped 60%.
• Despite the losses, the investor is holding onto 50,000 shares of GameStop as well as 500 call options in the brick-and-mortar video game retailer.
• At GameStop's record high last week, Gill's total return in the name ballooned more than 2,000% to as much as $33 million, according to his Reddit posts.

Keith Gill — who goes by DeepF------Value on Reddit and Roaring Kitty on YouTube — says he suffered a loss north of $13 million on Tuesday alone from his GameStop bet, but he's still not selling.

He's the man who helped inspire the epic short squeeze in GameStop last week that sent shockwaves through Wall Street. Through YouTube videos and Reddit posts, Gill attracted an army of day traders who cheered each other on and piled into the brick-and-mortar video game stock and call options, creating a massive short squeeze as the shares jumped 400% last week alone.

Gill says he has been holding 50,000 shares of GameStop as well as 500 call options in the brick-and-mortar video game retailer since the start of 2021. At GameStop's record high last week, Gill's total return in the name ballooned more than 2,000% to as much as $33 million, according to his Reddit posts.

However, the short squeeze in GameStop started to fade this week, taking a big bite out of Gill's massive gains. The trader apparently lost $13.6 million on his positions in GameStop shares and calls, following a more than $5 million loss on Monday.

The gaming retailer stock dropped 60% on Tuesday and it has lost more than 70% of its value since Friday.

Gill started touting GameStop six months ago on YouTube, explaining to his subscribers how the 100%-plus short interest in the name could work to their advantage. While on Reddit's infamous WallStreetBets forum, he's been posting screenshots of his GameStop returns for more than a year, in what he calls his "GME YOLO update (You Only Live Once)."

The investor owned 10,000 shares of GameStop at the end of 2020 and increased his holding in the new year, according to his posts on Reddit.

Gill's latest seven-hour YouTube live stream on Jan. 22 detailing his GameStop trades garnered more than 650,000 views.

"Cheers everybody," Gill said in the video to his more than 300,000 subscribers, holding a champagne class. "A historic day today, no doubt a gigantic day."

The Wall Street Journal interviewed the 34-year-old investor last week in a profile, which revealed his background as a college track star as well as a former marketer for Massachusetts Mutual Life Insurance.

Gill didn't respond to CNBC's request for comments via Twitter and Reddit.

— CNBC's Jared Young contributed reporting.

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