Bill Ackman

Pershing Square's $13.7B book made one decisive move: initiating MSFT at 15.3% of the portfolio—roughly $2.1B—instantly making it the fourth-largest holding in a fund that already runs just 11 positions. This is textbook Ackman: high-conviction, large-cap compounders with durable pricing power, and MSFT fits squarely alongside AMZN (17.4%), UBER (15.7%), and META (11.1%) as a mega-cap tech/platform cluster that now represents over 59% of AUM. Simultaneously, Ackman nearly eliminated his Google exposure, cutting both GOOG (–95%) and GOOGL (–95%) to rounding-error weights totaling under 0.7%—an implicit rotation from Alphabet into Microsoft that may reflect a preference for Azure/Copilot monetization over Google's AI search risk. HLT (5.6%) was fully exited, removing the lone hospitality name and tightening the portfolio's thematic coherence around compounding platform businesses. The concentration here is extreme: top 5 now at 78.2%. Watch whether Ackman adds to MSFT to challenge BN or AMZN for the top slot next quarter.