Microsoft Reclaims $4 Trillion Market Cap as AI Momentum Lifts Shares

Microsoft Corp. closed trading on Tuesday at $542.07 per share, a 2 percent gain that lifted the company’s market capitalization to approximately $4.04 trillion. The advance returned the software maker to the small group of publicly traded firms valued above $4 trillion, a threshold it first crossed in July. Graphic-chip producer Nvidia Corp. remains a member of the group, while Apple Inc. touched the mark briefly during the session before ending the day just below it.

The renewed climb in Microsoft’s stock followed two developments tied to the artificial-intelligence sector. Earlier in the day, OpenAI announced that it had converted its operations into a public benefit corporation after receiving clearance from the attorneys general of Delaware and California. In conjunction with that change, the research lab signed a new agreement granting Microsoft an estimated 27 percent ownership stake in the reorganized, for-profit entity. Microsoft has been OpenAI’s principal financial supporter since 2019.

The dual announcements underscored Wall Street’s ongoing enthusiasm for companies positioned to profit from rapid adoption of generative AI tools. Investor demand has driven the valuations of Microsoft, Nvidia and Apple to record levels in 2024 and 2025, placing them well ahead of other U.S.-listed firms by market value.

Microsoft’s trajectory to the $4 trillion tier

Microsoft surpassed the $1 trillion mark in 2019 and reached $2 trillion in June 2021. The company crossed $3 trillion in January 2024 and first exceeded $4 trillion on 12 July 2025, becoming the second corporation after Nvidia to do so. Tuesday’s close represents the second time the company has finished a trading day with a valuation above the milestone.

The Redmond, Washington–based business has expanded beyond its legacy Windows franchise by investing heavily in cloud computing, subscription software and artificial intelligence services. Much of investors’ current focus centers on Azure, Microsoft’s cloud platform, which integrates OpenAI models into offerings such as the Copilot suite and GitHub’s coding assistant.

Apple’s brief appearance above the threshold

Apple crossed $4 trillion in intraday trading when its share price rose above $270, but it finished marginally lower at $269, corresponding to a market capitalization of about $3.99 trillion. Apple, propelled for years by iPhone sales, achieved the first $1 trillion valuation among publicly traded companies in August 2018, reached $2 trillion in 2020 and $3 trillion in January 2022.

Although Apple lost its $4 trillion status by the closing bell, its proximity to that level reflects continued demand for its hardware, services and expanding AI-related features. Analysts will watch upcoming quarterly results for additional signals on whether the company can sustain momentum in the face of intensifying competition and regulatory scrutiny.

Nvidia remains the AI benchmark

Nvidia, whose graphics processors are widely used to train large language models, first reached the $4 trillion threshold in June 2025 and has largely remained above it. The company’s chips form the backbone of data-center infrastructure required by cloud platforms, social media networks and research institutions building advanced AI applications.

The semiconductor firm’s rapid revenue growth and dominant market share have made its stock emblematic of the broader AI rally. Microsoft’s partnership with Nvidia on cloud services and high-performance computing has further highlighted the interdependence of leading technology suppliers within the AI ecosystem.

Imagem: imagem internet 20

Details of OpenAI’s restructuring

OpenAI stated that its new public benefit corporation structure enables it to pursue long-term research goals while generating commercial returns. Public benefit corporations are recognized under Delaware law as entities that balance shareholder value with stated public-interest objectives. Additional information on the legal framework is available from the U.S. Securities and Exchange Commission.

The attorneys general of Delaware and California indicated they would not challenge OpenAI’s conversion, removing a potential roadblock for Microsoft’s increased involvement. The roughly 27 percent stake that Microsoft will receive expands an alliance that already included multibillion-dollar cloud commitments and the integration of OpenAI models into Microsoft products.

Market context and investor sentiment

Collectively, Microsoft, Apple and Nvidia account for an outsized portion of the S&P 500’s total value. Their movements heavily influence index performance, and shifts in their share prices can ripple throughout global markets. The trio’s ascent underscores how capital has concentrated in companies perceived to have clear strategies for deploying AI at scale.

Nevertheless, some market strategists caution that elevated valuations leave little room for execution missteps. Quarterly earnings, regulatory developments and competitive pressures remain key variables that could affect future price trajectories.

For now, Microsoft’s latest return to the $4 trillion echelon reinforces its position among the world’s most valuable enterprises and signals sustained confidence in its approach to cloud computing and artificial intelligence.

Crédito da imagem: The Associated Press