Microsoft has been sued by shareholders in the United States after investors accused the company of failing to properly disclose challenges facing its Azure cloud business and the scale of spending required to support its artificial intelligence infrastructure.
The proposed class action was filed in a federal court in Seattle by the City of St. Clair Shores Police and Fire Retirement System, a Michigan pension fund.
The lawsuit names Microsoft Chief Executive Officer Satya Nadella, Chief Financial Officer Amy Hood and other company executives as defendants.
Shareholders claim Microsoft gave investors an incomplete picture of Azure’s performance and the financial demands of its AI expansion between May 1, 2025 and January 28, 2026.
According to the complaint, the company downplayed the impact of high cost infrastructure while overstating the strength of products such as Copilot and the benefits of its partnership with OpenAI.
The case follows a decline in Microsoft’s share price earlier this year. On January 29, the stock fell 10% after the company released its quarterly earnings a day earlier, wiping about $357 billion from its market value. It was Microsoft’s biggest one-day stock market loss in almost six years.
In its fiscal second quarter ended December 2025, Microsoft reported 39% growth in Azure and other cloud services revenue. While that matched analysts’ expectations, it was a slowdown from the 40% growth recorded in the previous quarter.
The company also projected Azure growth of between 37% and 38% for the following quarter.
At the same time, spending still increased. Microsoft reported capital expenditure of $37.5 billion during the quarter, up nearly 66% from a year earlier and well above analysts’ forecast of $34.3 billion.
The lawsuit argues that Azure’s slower growth and the increase in spending were linked to capacity constraints as Microsoft redirected resources towards AI development.
Investors allege the company devoted significant investment to AI infrastructure, research and products such as Copilot without adequately warning shareholders about the financial impact.
Microsoft has invested heavily in AI infrastructure in recent years, including data centres, graphics processing units and custom chips designed to support growing demand for AI services.
Estimates reveal the company’s AI infrastructure spending reached an annualised run rate of roughly $37 billion during the 2026 financial year.
The company’s relationship with OpenAI also features in the lawsuit. Shareholders claim the partnership helped create an impression of sustained growth and competitive strength, while masking challenges within Azure’s underlying business. Microsoft remains OpenAI’s largest investor.
The shareholders sued Microsoft at a time when investors are scrutinising the billions of dollars being spent on AI across the technology industry.
Companies including Amazon and Google are also investing heavily in AI infrastructure, but the lawsuit alleges Microsoft’s disclosures to investors failed to fully reflect the risks and costs involved.
Microsoft has rejected the allegations.
“Microsoft stands by the integrity of its public statements and will vigorously defend itself in court,” the company said.
The case seeks to represent investors who bought Microsoft shares during the proposed class period and suffered losses following the stock’s decline in January.
