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.

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.

Ackman described Microsoft as a “core holding” for Pershing, though he did not disclose the size of the firm’s stake. Pershing owns shares of several Big Tech giants, including Meta, Amazon and Google.

Wall Street has been concerned about slowing growth in Microsoft’s Azure division, as well its massive AI-related spending.

The company has also struggled to maintain enough cloud computing capacity to keep pace with a massive uptick in AI demand.

Ackman said he’s undeterred by the increased spending at Microsoft, arguing it “should drive future revenue generation.”

He also praised Microsoft’s recent move to restructure its revenue-sharing agreement with OpenAI, which capped the latter’s payments to Microsoft at $38 billion.

“We view Microsoft’s recent decision to restructure its OpenAI partnership not as a concession but as part of a deliberate pivot toward a more open, multi-model architecture that better serves enterprise customers, who increasingly seek optionality across model providers,” he wrote.