Keith Gill scored a one-day gain of $79 million after disclosing his GameStop stake on Reddit

• Keith Gill scored a $79 million one-day gain on his GameStop bet on Monday.
• The massive gains were initially sparked by Gill disclosing his bet on GameStop worth more than $100 million.
• Part of Gill's GameStop bet is a $20 call option on the stock that expires later this month.

Keith Gill still has diamond hands.

That's based on a "GME YOLO update" post Gill made to Reddit on Monday after the market close, which included a screenshot of his E*Trade brokerage account.

The screenshot showed that after GameStop stock's 21% surge on Monday, Gill still held onto all of his 5 million shares and 120,000 call options of the video game retailer.

Monday's trading action in GameStop minted Gill a $33.6 million one-day profit on his stock position, and a $54.3 million gain on his call option stake, bringing his one-day gain to a whopping $79 million.

Gill's GameStop call options expire on June 21. They give him the option to acquire 12 million shares of the company at the $20 strike price. 

Including total cash of $29.3 million, Gill has a total account value of $289.3 million, and he is also now the fifth largest shareholder in GameStop.

The sharp rise in GameStop stock was initially sparked by Gill himself after he returned to Reddit for the first time in years to post a screenshot of his brokerage account on Sunday from his famed "DeepFuckingValue" account.

The Reddit post came a couple weeks after Gill's "Roaring Kitty" Twitter account posted a deluge of memes and sparked another rally in the meme-stock.

Business Insider could not confirm if Gill himself made the Reddit post on Sunday and Monday, nor if the screenshot of his brokerage statement was authentic. 

Gill's social media posts and the subsequent trading activity in GameStop stock has sparked concerns of potential market manipulation, with E*Trade reportedly weighing a decision to kick Gill off of its platform.  Some people online have also speculated that Gill isn't actually posting, and that he's no longer in control of the social media accounts that sparked the latest rally.