While the actual fourth-quarter (Q4) 13-f filing is yet to be published, a February 11 Pershing Square (LON: PSH) presentation revealed a massive new technology bet made late last year by the billionaire investor Bill Ackman.
Specifically, in the section covering the equity portfolio update, the company unveiled a massive position in Mark Zuckerberg’s Meta Platforms (NASDAQ: META). While the exact value of the investment was not known at press time on February 16, the document reveals it accounts for about 10% of the portfolio.
Considering the Q3 2025 13-f filing showed the value of Pershing Square’s holdings at about $14 billion, it is possible Bill Ackman invested approximately $1.5 billion in META stock.
The document also revealed that Pershing Square’s reasoning behind investing in Meta shares is mostly straightforward.
Why Bill Ackman made the massive Meta stock investment
According to the presentation, the blue-chip technology giant has a ‘high-quality advertising business,’ a strong balance sheet, a 22% annual growth rate in 2025, and its business model ‘is one of the clearest beneficiaries of AI integration.’
Indeed, Bill Ackman’s argument for adding Meta stock to the firm’s portfolio is summarized well in the document itself:
“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.”
How Meta’s performance squares against Bill Ackman’s analysis
Meta’s latest earnings report certainly reinforces Pershing Square’s investment case. The January 28 document revealed the firm beat both the revenue and the earnings per share (EPS) forecasts, recording $59.89 billion and $8.88, respectively.
Additionally, investors were especially impressed with the accompanying revenue forecast late last month. Meta’s estimate that its sales will amount to between $53.5 billion and $56.5 billion in 2026 – at the time, analysts were predicting a whole-year figure of $51.41 billion – helped the stock soar approximately 10% in a day.
Trading since, however, tells a somewhat different story. The earnings report upsurge was swiftly accompanied by a plunge as the wide technology sector exposure to artificial intelligence (AI) began weighing heavily on the market.
In the year-to-date (YTD) chart, Meta stock is 3.08% down, and its press time price of $639.77 is 13.35% below the January 29 high of $738.31.

Zooming out to the 12-month chart also paints Meta Platforms as a lagging company, considering its equity is down 10.69% within the timeframe. On the flip side, the stock market performance, when juxtaposed with the firm’s strong results, reinforces the argument that META shares are significantly undervalued.
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