** Microsoft MSFT.O shares advance 0.6% to $411.76 before the bell after Bill Ackman's Pershing Square disclosed a new stake, citing a "compelling" valuation

** Ackman said MSFT's Azure cloud and M365 Office suite place the co at the center of rising AI adoption by businesses

** Pershing began building its position in Feb after the stock slumped, with Ackman adding that he believes concerns about competition and changes to its OpenAI partnership are overblown

** MSFT stock recently at 21 times expected forward earnings, vs a 5-yr avg of 29, suggesting it may be undervalued, per LSEG data

** Shares down ~15% YTD and well underperforming the Nasdaq's .IXIC ~15% advance. Stock ~26% below record intraday high of $555.45 reached on July 31, 2025

** 56 of 60 analysts covering the stock rate it "strong buy" or "buy", 4 "hold"; median PT $560