Bill Ackman Quietly Adds Four Mystery Stocks to His Portfolio — Here's What We've Uncovered

Bill Ackman has signaled four new investments for his Pershing Square Capital Management funds, according to Reuters reporting from June 2026. While the specific identities of these four holdings were not disclosed in available sources, the announcement comes as Ackman's $14.6 billion fund maintains a notably concentrated portfolio structure dominated by mega-cap equities.

Ackman's largest positions as of March 31, 2026 reflect a technology and consumer-focused strategy. Brookfield Corp represents 17.62% of portfolio holdings, with Amazon at 17.39%, Uber Technologies at 15.71%, Microsoft at 15.26%, and Restaurant Brands International at 12.20%. These five positions alone account for substantial concentration risk. The fund also maintains significant exposure to other technology names including Alphabet and Meta, which collectively comprised over 39% of holdings at various points in the fund's recent history.

Portfolio activity during Q4 2025 was notably elevated, with Ackman's most significant move being the complete exit from Chipotle—a position the fund had held for an extended period. This exit suggests a shift in conviction regarding restaurant and consumer discretionary positioning, contrasting with the maintained large stakes in Uber and Restaurant Brands International.

The announcement of four new positions reflects Ackman's stated emphasis on diversification across market sectors, though the current portfolio demonstrates significant concentration in technology and consumer discretionary equities. Pershing Square's publicly traded vehicles (ticker PS and PSUS) launched on the NYSE alongside this active portfolio management, though analyst commentary has expressed caution regarding the quoted instruments' performance relative to underlying fund positioning.