Microsoft shares jumped as much as 17 percent on Thursday, adding roughly $483 billion in market value in a single session, the biggest one-day gain since 2008, after quarterly results finally convinced investors that the company's massive AI spending is translating into accelerating cloud revenue. The stock closed Wednesday at $390.54, down nearly 30 percent from an October 2025 high of $555, and briefly touched $456 in afternoon trading as the gloom lifted.

The numbers that mattered

Quarterly revenue hit $90 billion, about $2.4 billion over the $87.6 billion consensus and up $13.6 billion, or 17.7 percent, from a year ago. Earnings per share came in at $4.74 against a $4.24 estimate, on net income of $35.8 billion. But Azure took center stage. Satya Nadella disclosed that the cloud platform crossed $100 billion in revenue for the first time during the 2026 fiscal year. William Blair analyst Jason Ader estimated fourth-quarter Azure revenue at $29.9 billion, up from $20.9 billion a year earlier, 43 percent growth that sailed past the company's own 39 to 40 percent guidance. Amy Hood then guided 45 percent Azure growth for the September quarter, above the 41 percent analysts had expected.

The OpenAI concentration question

The annual report disclosed that OpenAI accounted for $24.1 billion in fiscal 2026 revenue and still owes Microsoft $6 billion in accounts receivable. Analysts estimated OpenAI was responsible for roughly half of Azure's $30 billion in year-over-year growth, a concentration risk that has long unsettled investors. BNP Paribas senior equity research analyst Stefan Slowinski, who carries a $549 price target, countered that the $24.1 billion represents less than a quarter, 23 percent, of Azure revenue, and argued Microsoft has a path to keeping growth above 40 percent as it phases in consumption-based pricing across Copilot.

The spend versus return narrative

The rally marks a turning point in the will-they-won't-they narrative around Microsoft's revenue trajectory versus its capital expenditures. The company is on track to spend an estimated $190 billion on AI this year, part of a hyperscaler build-out now expected to exceed $850 billion across the industry. Stifel's Brad Reback flagged that the OpenAI relationship is becoming less competitively additive as Google follows hard on Azure's heels, while Amazon Web Services remains the market-share leader. For now, the market has decided the spend is earning its keep. The next test arrives in September.