Chewy (CHWY) stock soared more than 20% in pre-market trading on Monday before paring gains after an SEC filing revealed popular investor Keith Gill has a 6.6% stake in the company.

Shares were up more than 11% just before the opening bell.

The July 1 filing showed Gill, a popular meme stock trader who goes by the online name "Roaring Kitty," now owns 9.1 million shares of Chewy.

The filing comes after a post on X from Roaring Kitty sent Chewy shares soaring as much as 30% on June 27. The account posted a cryptic photo of a dog at 1 p.m. ET, sending the stock surging before it eventually lost gains and closed below the flat line.

Why Gill is interested in Chewy is largely unknown. Gill talked glowingly about current GameStop CEO Ryan Cohen, who is also the founder of Chewy, during a live stream on June 7 but hasn't made direct comments about the petcare provider. Notably, Cohen is no longer on the executive board at Chewy.

Gill's filing also provided little clues. Outside, of listing how many shares Gill owns, the 13-G filing provided one other detail. Gill included a box that asks to check the appropriate box for whether or not the filer is, or is not, a cat.

Gill checked the box labeled "I am not cat."

Last week's tweet and Monday's filing are the latest in a string of activity from Gill, who remerged online in May. In the past month and a half, Gill has posted a series of memes, revealed a large stake in the initial meme stock GameStop (GME) via screenshots, and hosted a YouTube live where he talked glowingly about GameStop.

On Friday, June 28, a class action lawsuit against Gill was filed, accusing Gill of misleading investors and potentially manipulating the market.

Despite massive stock jumps amid Gill's posts over the past month and a half, GameStop shares are now up just 3% over the past month.

Josh Schafer is a reporter for Yahoo Finance. Follow him on X @_joshschafer.

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