Billionaire investor Bill Ackman revealed Friday that his firm Pershing Square Capital has built a stake in Microsoft – and said the tech giant “offers analogous and compelling long-term value” despite a recent stock slump. Ackman, 60, wrote in a lengthy X post that Microsoft operates “two of the most valuable franchises in enterprise technology” in the form of its 365 productivity apps, which include Word and Excel, and its Azure cloud-computing business. “In our view, investors underestimate the resilience of the M365 franchise given its deeply embedded role across enterprises and highly attractive price-value proposition,” the renowned moneyman wrote. Bill Ackman’s Pershing Square has taken a stake in Microsoft. Bloomberg via Getty Images Microsoft shares rose nearly 2% in early trading Friday following Ackman’s post. The company’s stock has endured a rough start to the year, with shares down nearly 12% since Jan. 1.…