In February 2026, investor Bill Ackman unveiled a new stock position, telling investors that shares of Meta Platforms (NASDAQ:META) were undervalued. That thesis has stalled in 2026, as the stock ranks among the weakest performers in big tech. Here's how much Ackman's newest position is down so far in 2026.

Ackman's Meta Position Down in 2026

Ackman unveiled that he bought Meta stock in February 2026. That position was later made official when Pershing Square disclosed its 13F quarterly filing.

Meta was the only new position taken by Pershing Square Capital in the fourth quarter. The fund exited its position in Chipotle Mexican Grill in the fourth quarter.

The fund bought 2,673,569 shares of Meta on an unknown date in the fourth quarter. At the end of the quarter, the position was valued at $1.76 billion and represented around 11% of the fund's assets.

Other changes to the fund included increasing its Amazon.com Inc (NASDAQ:AMZN) position by 65% and cutting its stake in Alphabet Class A (NASDAQ:GOOGL) and Alphabet Class C (NASDAQ:GOOG) shares by 86% and 2%, respectively.

With a price of $614.34 for Meta stock on Wednesday, the stock continues to fall in 2026, lowering the value of Ackman's stake.

The new position from the fourth quarter is now worth $1,642,480,379.46. This means Ackman is down $120,818,583.11 on the Meta position in 2026 alone. This comes as Alphabet shares are up over 25% year-to-date in 2026.

Ackman recently completed the IPO process of Pershing Square (NYSE:PS) and Pershing Square USA (NYSE:PSUS), with the latter mirroring the investments of his Pershing Square Capital Management fund.

Ackman's Meta Thesis

Announced days ahead of the 13F filing, Ackman revealed several reasons why Pershing Square took a large position in the Magnificent Seven company.

“We believe Meta’s current share price underappreciates the company’s long-term upside potential from AI and represents a deeply discounted valuation for one of the world’s greatest businesses,” the firm said in the presentation. Meta is a “leader in the fast-growing digital advertising space and one of the clearest beneficiaries of AI integration,” it added.

“We believe concerns around META’s AI-related spending initiatives are underestimating the company’s long-term upside potential from AI,” it said.

The presentation highlighted Meta’s 3.5 billion daily active users and a growing user base. An experienced leadership team and the company’s stock multiples are also highlighted as reasons to be bullish going forward.

Meta is the newest Magnificent Seven bet by Ackman, with Pershing Square taking stakes in Alphabet and Amazon in recent years. Shares have been underwater most of 2026, and Ackman's newest position is losing value.

This could be bad news for Pershing Square and the new public stocks that track its company and fund. Pershing Square saw net asset value growth of 20.9% in 2025, according to the presentation, beating the S&P 500 (+16.6%).

Ackman and Pershing Square will release their newest 13F later this month, which will reveal if any new positions were taken in the first quarter and if the Meta stake remained the same, was cut, or increased.

Photo created by Midjourney, Dall-E