(Reuters) - Unity Software's (U) shares rose nearly 10% on Thursday as a cryptic post by "Roaring Kitty" on social media platform X sparked enthusiasm, following a challenging year for the videogame software maker.

Keith Gill, popularly known among traders as "Roaring Kitty," shot to fame during "the meme stock frenzy" that gripped Wall Street in 2021 and triggered an eye-popping rally in GameStop's shares.

Gill posted a small clip about late musician Rick James on X, who featured in a song named "Unity," triggering interest in the stock.

The company behind the Unity Engine software, a platform used to create video games, is set to add more than $700 million to its market valuation, if gains hold. Its shares rose as high as $26 on the first trading day of 2025.

"The leader of the meme stock post on social media, whether it's Reddit or X, you're certainly going (to) see that reaction by that small army of meme stock players — that's what we're seeing again today," said Art Hogan, chief market strategist at B. Riley Wealth.

Unity's shares fell about 45% in 2024, as the company introduced a pricing policy "runtime fee" in 2023, which it had to scrap the next year after facing severe backlash from the videogame developer community.

Millions of game creators rely on its software toolkit each month, including the maker of the popular "Pokemon Go," "Beat Saber" and "Hearthstone" games.

Last year, the company announced layoffs of about 25% of its workforce, following 8% of job cuts in 2023, in a bid to focus on profitability.

Gill, who disclosed a 6.6% stake in pet products retailer Chewy, had dissolved his entire stake last year. In June 2024 GameStop's stock tanked after Gill's livestream failed to spark investor enthusiasm.

"You would think people would have learned by now that playing these silly reindeer games end in tears ... it's not the way to invest," said Thomas Hayes, chairman at Great Hill Capital LLC.

(Reporting by Jaspreet Singh, Pranav Kashyap and Johann M Cherian in Bengaluru; Editing by Alan Barona)