Micron Stock Plunges 30% Despite AI Boom—Should You Buy?

Micron Technology's stock has experienced dramatic swings tied to the artificial intelligence hardware cycle. The company's fiscal 2026 third quarter (ended May 28) delivered record revenue of $41.4 billion（約6.6兆円）, a 346% increase from the year-ago period, along with earnings of $24.67 per share—a staggering 1,368% year-over-year jump. This performance was driven largely by booming sales of high-bandwidth memory (HBM) for AI data centers, which Micron supplies to infrastructure operators and chip makers like Nvidia.

HBM is critical infrastructure for AI workloads because it stores data in a ready state for graphics processing units (GPUs) to access during computation. Without sufficient HBM capacity, GPUs pause while waiting for data, creating sluggish performance for users of AI chatbots and agents. Micron recently began shipping its HBM4 chips, which provide 60% more capacity and 20% better energy efficiency compared to its previous HBM3E generation. Nvidia has adopted HBM4 for its new Vera Rubin GPU systems. The data center HBM market was valued at $35 billion（約5.6兆円） last year, and Micron projects it will nearly triple to $100 billion（約16兆円） by 2028.

Yet the stock peaked at $1,213 last month and has since plummeted 30% to close at $848 on Friday, July 17. This reversal reflects mounting concern that the AI spending boom is not durable. A recent UBS survey found that 60% of businesses are curbing their AI spending by routing tasks to cheaper, more efficient models. Infrastructure costs have forced AI providers such as Anthropic and Microsoft to implement price increases, prompting customers to reconsider deployment. Large corporations are visibly tightening controls: Walmart, Amazon, and Uber have recently capped AI usage for employees to prevent budget overruns. Uber's chief operating officer noted that the company burned through its entire 2026 budget in just four months by using Anthropic's Claude Code, making it harder to justify continued spending.

This demand uncertainty collides with an impending supply surge. Every major memory manufacturer is frantically building additional manufacturing capacity to meet current demand. Once supply catches up, Micron and competitors will lose their ability to dictate prices, significantly pressuring profit margins. Micron's forward price-to-earnings ratio is just 5.6 based on Wall Street's fiscal 2027 estimate, compared to the Nasdaq-100's 33.4, suggesting investors are skeptical the memory boom will sustain its current trajectory. Management's guidance for the fourth quarter (ending late August) projects $50 billion（約8兆円） in revenue and $30.73 per share in earnings, pointing to more record results in the near term. However, the analyst cited in the article views near-term volatility as likely and suggests waiting to invest until "physical AI segments such as autonomous vehicles and robotics are commercialized at scale," a timeline that extends beyond the current uncertainty.

Micron's stock collapse from $1,213 to $848 masks a paradox: the company's fundamentals appear to support growth, yet the market is pricing in significant skepticism about the AI boom's staying power. The core tension stems from a mismatch between near-term supply and demand dynamics. On one side, Micron's HBM chips are essential infrastructure for AI inference and training, and the company's fiscal 2026 Q3 results—$41.4 billion（約6.6兆円） in revenue, up 346% year-over-year—demonstrate explosive near-term demand. Its forward price-to-earnings ratio of just 5.6 is far below the Nasdaq-100's 33.4, suggesting the market has priced in a sharp pullback.

On the other side, multiple headwinds are emerging. A UBS survey indicating that 60% of businesses are curbing AI spending, combined with public statements from Uber's chief operating officer and confirmed spending caps at Walmart, Amazon, and Uber, signal that customers are retreating from aggressive AI deployment. Simultaneously, Micron and its competitors are ramping capacity to meet current demand, which will inevitably increase supply. Once supply normalizes, the company will lose its pricing power—a critical driver of its current profit margins. The body suggests that Micron's long-term upside depends on "physical AI segments such as autonomous vehicles and robotics" reaching commercial scale, a timeline that extends well beyond the near-term volatility the stock is likely to face as memory supply rises and demand clarifies.