Sources claim that ValueAct, an activist investor, holds a $1 billion stake in Meta.

• According to sources, Meta has a roughly $1 billion stake in ValueAct.
• Mason Morfit, CEO of ValueAct, is reportedly broadly supportive of Mark Zuckerberg's AI push, although specific plans of the activist are not yet known.
• The largest company ever to be targeted by a major activist is Meta, with a market cap of $1.5 trillion.

According to sources, ValueAct, an activist investor, holds a $1 billion stake in Facebook's parent company.

One person stated that ValueAct CEO Mason Morfit supported Meta's efforts to invest in artificial intelligence, although the specific plans of the activist fund could not be immediately learned.

This year, the growth of Meta shares has been impressive, surpassing the S&P 500 and other peer companies. ValueAct, known for its collaborative approach to investing in technology companies, has a history of investing in such companies. For instance, it signed an information-sharing agreement with Disney during its activist battle with Nelson Peltz's Trian Partners.

Meta, the parent company of Facebook, Instagram, and WhatsApp, is one of the largest companies targeted by an activist investor, with a market cap of nearly $1.5 trillion. In 2022, the company was targeted by Brad Gerstner's Altimeter Capital, who pushed the company to reduce its headcount in a letter titled "Time to Get Fit."

Salesforce, Disney, and Microsoft are among the mega-cap companies that ValueAct has invested in, while Morfit has advocated for changes at smaller technology companies, including Salesforce.

Meta did not immediately respond to a request for comment.

— CNBC's David Faber contributed to this report.

This is a developing story. Please check back for updates.