BlackRock has likely made $1.2 billion on GameStop as day traders buy the stock to stick it to Wall Street

• BlackRock has likely scored a 700% gain on GameStop this month, thanks to day traders boosting the stock.
• The world's largest asset manager owned 9.2 million shares worth $174 million at the end of 2020.
• BlackRock's 13% stake has surged in value from $174 million to around $1.4 billion since then.
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The GameStop saga is being framed as the little guys sticking it to Wall Street. However, the world's biggest fund manager has probably made $1.2 billion this month thanks to those amateur investors pumping up the video-game retailer's stock.

BlackRock disclosed in a regulatory filing on Tuesday that it owned 9.2 million shares in GameStop at the end of December. GameStop's stock price has skyrocketed from about $19 to $148 since then.

Assuming BlackRock hasn't altered its roughly 13% stake, its value has surged from $174 million to around $1.4 billion this year - an almost 700% gain in less than a month.

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The asset manager could have made even more money. It owned 15.1 million GameStop shares as recently as May 2019, which would have been worth around $2.2 billion as of Tuesday's close.

BlackRock's gains are largely down to day traders working in concert to drive up GameStop's stock price. They have also targeted other heavily shorted stocks including AMC, BlackBerry, and Bed Bath & Beyond. Their goal is to make fast profits and force short-sellers to cover their positions, which drives the stocks even higher.

The amateur investors, who plan their purchases on Reddit forum r/wallstreetbets and other sites, have specifically targeted the short positions of hedge funds such as Melvin Capital, seeking to squeeze them into submission. Melvin agreed a $2.8 billion bailout from the firms of billionaire investors Steve Cohen and Ken Griffin on Monday.

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BlackRock isn't the only one cashing in on GameStop's breathless rally. Ryan Cohen, the Chewy cofounder and activist investor who recently secured a seat on the retailer's board, has scored a 1,700% gain on his investment last year.

Michael Burry, the Scion Asset Management boss and a key character in Michael Lewis' book "The Big Short," has also seen his stake balloon in value by as much as 1,500% in under four months. However, he blasted the GameStop buying as "unnatural, insane, and dangerous" in a quickly deleted tweet on Tuesday.