Bill Ackman built his fortune through Pershing Square Capital Management by taking large positions in companies he believes in, often concentrating his bets rather than diversifying broadly. This approach has included activist campaigns and short positions, like his notable bet against Herbalife (NYSE:HLF).
Ackman’s strategy emphasizes deep research into high-quality businesses with durable growth. In the fourth quarter, his fund made several adjustments. He completely exited its position in Chipotle Mexican Grill (NYSE:CMG), and increased his stake in Amazon (NASDAQ:AMZN | AMZN Price Prediction) by about 65%, bringing the total to roughly 9.6 million shares, which now represents 14% of the portfolio.
But there was only one new stock Ackman bought in Q4: Meta Platforms (NASDAQ:META). Does the social media and artificial intelligence (AI) giant belong in your portfolio, too? Here’s why Ackman is so bullish about Meta.
Going Big on Meta
Pershing Square purchased approximately 2.7 million shares of Meta Platforms valued at around $1.8 billion. This makes Meta the fund’s fifth-largest holding, accounting for about 11% of the $15.5 billion portfolio, behind Brookfield (NYSE:BN), Uber Technologies (NYSE:UBER), Amazon, and Alphabet (NASDAQ:GOOG). The move was decidedly opportunistic as it occurred after Meta’s stock suffered a sharp drop following its third-quarter earnings due to investor concerns over its AI-related capital expenditures.
With Ackman’s significant bet on Meta, investors may wonder if the stock fits their own holdings. Although Pershing Square’s position highlights Meta’s potential, individual risk tolerance and diversification needs vary, so it might not be a good fit for you, but below are the main reasons Ackman has outlined for his bullish stance.
Why the Billionaire Is Bullish on Meta
In 2025, Meta generated $200 billion in revenue, up 22% year-over-year, driven by its core Family of Apps segment, including Facebook, Instagram, and WhatsApp. This segment relies on advertising, while the Reality Labs division — focused on wearables and metaverse projects — incurs losses that represent about 25% of overall profits.
Meta leads the digital advertising market, which Pershing Square views as a fast-growing sector. The company has over 3.5 billion daily active users across its apps, with user growth at 7% in Q4. A key factor is Meta’s integration of AI, which enhances user engagement through content recommendations and improves ad targeting using first-party data. Its AI-driven ad ranking has delivered about four times more revenue impact than simply increasing ad load, with both ad prices and impressions accelerating.
Nvidia‘s (NASDAQ:NVDA) Jensen Huang recently praised Meta as the top AI deployer, stating in a CNBC interview that its approach yields real rewards from massive investments. He noted Meta’s shift to generative AI has transformed its business, driving earnings growth and justifying continued spending.
AI also supports self-serve tools for advertisers and opens new opportunities like business AI assistants and wearables. Pershing Square notes Meta’s history of cost control, such as the 2023 “Year of Efficiency” initiative, and recent cuts in Reality Labs spending. The fund believes front-loading AI investments will drive long-term earnings growth, especially after a planned spending increase in 2026.
Meta Platforms is Cheap
On valuation, Meta trades at 22 times next-twelve-months price-to-earnings, which Pershing Square considers attractive given growth prospects. Excluding Reality Labs losses, the core advertising business is valued at a forward P/E of under 20 times. Meta’s competitive edges include scale effects, where more users improve platform utility and data enables precise targeting. Meta’s strong balance sheet and high-margin core operations also provide flexibility for investments.
Pershing Square sees Meta as well-positioned among AI beneficiaries, with leadership in ads, data infrastructure, and research. Since initiating the position, Meta’s shares rose 2% through year-end and 3% year-to-date in 2026.
Key Takeaway
Investors should, of course, conduct their own due diligence before purchasing any stock, assessing factors like financial goals and market conditions. That said, Ackman presents strong, compelling arguments for Meta Platforms through Pershing Square’s analysis, emphasizing its advertising dominance, AI upside, and an undervalued core business.
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