Bill Ackman flags Meta stock undervalued as Pershing Square reveals big stake

Billionaire investor Bill Ackman is telling markets Meta Platforms is too cheap, and this time, he has fresh money behind the claim.

His firm, Pershing Square, has disclosed a new, sizeable position in the Facebook parent that represents roughly a tenth of the hedge fund’s capital, a bet reported at around $2 billion.

The move puts one of Wall Street’s most closely watched stock pickers squarely in the middle of the debate over Big Tech valuations and AI spending.

At a moment when investors are re‑rating mega‑cap tech on the back of massive AI investment plans and higher-for-longer rates, the stake disclosure does more than add another bullish soundbite.

It ties Ackman’s argument about Meta’s “deeply discounted” price directly to capital at risk, potentially shaping sentiment among other institutions.

Meta stake disclosure lends weight to Ackman’s valuation call

Pershing Square outlined the Meta position at its annual investor update on Wednesday, describing a stake that amounts to about 10% of the firm’s investment capital as of the end of 2025.

The Wall Street Journal reported that the holding, built quietly since late November, translates to roughly $2 billion based on previous disclosures about Pershing’s asset base.

The percentage refers to Pershing’s own portfolio, not Meta’s market value, and detailed share counts and ownership percentages are expected to be reflected in upcoming SEC filings.

This is a new position rather than a long‑held name.

Recent portfolio updates show Pershing Square adding fresh stakes in Meta, Amazon and Hertz while exiting or trimming consumer names such as Chipotle and Nike.

Given Pershing’s deliberately concentrated approach, it typically holds only a small handful of stocks devoting around a tenth of capital to a single company sends a strong signal of conviction.

For other fund managers and sophisticated retail investors, that alignment between public rhetoric and actual portfolio weight often matters as much as any phrase in an investor letter.

What Ackman’s valuation call means

In Pershing Square’s presentation, Ackman’s team argued that 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 core of the thesis is straightforward: heavy AI investment should deepen Meta’s moat in advertising and engagement, while markets are focusing too much on near‑term capital expenditure.

That view lands against a mixed backdrop.

Meta stock have slipped by roughly the low‑teens percentage range over the past six months as investors fretted over surging infrastructure budgets.

Yet most major Wall Street firms still rate the stock a buy, with average 12‑month targets implying around 20% to 30% upside from recent trading levels.

On headline valuation metrics such as the price‑to‑earnings multiple, Meta no longer looks like the deep value outlier it was in 2022, but many analysts argue its growth, margins and balance sheet remain stronger.

Neutral observers frame Ackman’s move as an important, but not decisive, data point.

The Pershing Square stamp of approval could support the bull case that Meta is still mis‑priced relative to its earnings power and AI optionality.

At the same time, it does not erase familiar risks: regulatory pressure on social media, potential ad market softness if the economy wobbles, and the simple fact that AI capex could overshoot returns if the payoff takes longer than expected.