#美光市值突破1万亿美元 1. Background of the Event and Market Performance: Chip Feast Accelerates, Nasdaq and S&P Break Historic Highs Again

May 27th (May 26th US time), the Nasdaq and S&P 500 indices once again hit record closing highs, supported by the easing of US-China tariffs and optimistic US-Iran peace prospects. The core driving force behind the index rally came from a five-day surge in the semiconductor sector, with memory chip leader Micron Technology (Micron) becoming the absolute star of the night: its stock price soared nearly 20%, and its market capitalization broke the trillion-dollar mark for the first time, firmly entering the US stock "trillion-dollar club."
This was not an isolated one-day frenzy but a continuation of several months of structural revaluation of US tech stocks. Over the past year, the market’s pursuit of AI computing power has gradually extended from GPU manufacturers to downstream industries such as storage, packaging, and heat dissipation. Since early 2025, Micron’s stock has gained nearly tenfold, making it one of the most representative validation targets in this storage supercycle.
Besides Micron, other companies that also performed well that night included: SanDisk surged over 11%, continuing the full-year storage chip rally; Qualcomm rose nearly 8%, having already gained over 20% in the previous week, showing a broad rally rather than isolated stock movements.
2. Analysis of Core Driving Factors: Accelerated Revaluation Under the Resonance of Three Logical Layers
1. AI Computing Power Demand Evolves from "GPU Shortage" to "Memory Shortage," HBM Logic Continues to Materialize
The current bottleneck in AI large model training computing power has shifted from Nvidia’s GPU supply to high-bandwidth memory chips (HBM). Micron is one of the world’s three major HBM suppliers, and its entire HBM capacity for 2026 has already been sold out, indicating a severe supply-demand mismatch and a likely continued price increase. From an investment perspective, the focus of AI infrastructure construction is undergoing a structural shift: as GPU cluster sizes expand exponentially, the marginal constraint of storage bandwidth is replacing raw computing power as the system bottleneck. Previously, market pricing logic for Micron was still based on the "cyclical stock" paradigm—DRAM prices under pressure when PC and smartphone demand weaken—but the demand for HBM driven by AI data centers is fundamentally reshaping its valuation system.
2. Fundamental Changes in the Storage Industry: LTA Framework Reshapes Pricing Models
Micron’s nearly 20% surge was directly catalyzed by UBS’s upgrade of Micron’s target price from $535 to $1,625 on May 26, more than tripling. It’s important to note that UBS’s logic for the upgrade is not limited to traditional supply-demand analysis but focuses on a more systemic industry transformation—storage industry’s first implementation of enhanced long-term supply agreements (LTA).
This new business model breaks the old framework of simply locking in shipment volume and pricing based on market conditions. The new LTA introduces fixed pricing clauses, with contract durations generally extended to 3-5 years, typically in "2+3" (two years fixed price plus three years variable) or "3+2" modes. This mechanism is a valuation pivot for Micron: significantly improving gross margin visibility, replacing the "cyclical stock" label with valuation logic based on "infrastructure-like certainty assets." UBS predicts Micron’s market cap could expand to $1.8 trillion within 12 months, implying nearly 80% upside potential.
3. Geopolitical "Peace Expectations": Market Sentiment’s Excess Premium Amplifier
In addition to strong industry fundamentals, macro market sentiment also plays a crucial role. Around May 26, signals of phased easing in US-Iran relations emerged. In mid to late May, Trump frequently posted on social media about "peace agreements nearing completion" and "reopening the Strait of Hormuz," though details and progress remained highly uncertain. Nonetheless, these statements at sensitive moments provided a noticeable marginal boost to market risk appetite.
Semiconductors are among the most geopolitically sensitive sectors in the global supply chain. The easing of US-Iran relations directly impacts oil prices and the stability of global shipping routes, thereby reducing geopolitical risk premiums in broad asset pricing. When the AI sector already harbors strong bullish sentiment, the improvement in external geopolitical expectations acts like "adding fuel to the already burning furnace."
3. Key Stock Performance and Investment Logic
Micron Technology: The Fastest Path to a Trillion-Dollar Valuation, Revaluation Still Ongoing
Micron took only 48 days to jump from a $500 billion market cap to over $1 trillion, setting a record for the fastest crossing of the $500 billion to $1 trillion range in US stock history. This rapid ascent signals a strong shift: the market’s valuation logic for memory chip companies is rapidly transitioning from "cyclical discount" to "AI infrastructure premium."
So far this year, Micron has set 28 new closing price records, a rare frequency among US tech giants.
SanDisk: Returning as a Supercycle Winner
Since spinning off from Western Digital and re-entering the public market in February 2025, SanDisk’s stock has gained 580%, becoming the best-performing stock in the S&P 500 for the year. Its surge is not driven by a single catalyst but by a deep resonance between "passive ETF inflows triggered by index inclusion" and "fundamental revaluation during the storage supercycle"—the Nasdaq previously announced SanDisk’s inclusion in the Nasdaq 100, which objectively triggered large-scale passive ETF rebalancing, further boosting its momentum. Meanwhile, management’s statement that "supply growth will remain restrained through 2026" continues to reinforce market confidence in NAND industry’s supply-demand tightness.
Qualcomm: Differentiated Play on Edge AI
Qualcomm’s nearly 8% rise is driven by a slightly different logic from Micron and SanDisk, mainly due to accelerated deployment of AI at the consumer electronics edge. In May 2025, Qualcomm signed multi-year cooperation agreements with Xiaomi covering smartphones, automotive, AR/VR, etc., with Xiaomi confirming the first adoption of the next-generation Snapdragon 8 series platform. Earlier in May, Qualcomm’s single-day gain exceeded 10%, briefly hitting a stage high, indicating high market expectations for AI penetration at the edge from late 2025 to 2026.
Compared to storage chip makers benefiting from AI infrastructure at the training end, Qualcomm’s rally is more focused on the long-term narrative of AI applications extending from cloud to edge—giving it a certain differentiation within the current sector.
4. Summary and Outlook
On May 27, Micron’s market cap broke through $1 trillion, SanDisk and Qualcomm surged simultaneously, and the Nasdaq and S&P 500 hit new highs. These phenomena point to an irreversible trend: AI capital expenditure is systematically reshaping the valuation framework of the entire semiconductor industry, and the shift from "cyclical logic" to "growth logic" has just entered an acceleration phase.
Of course, risks should not be overlooked. Current valuation levels for storage chips have deviated from traditional historical ranges, and any signals of unexpected supply expansion or slowdown in AI capital spending could trigger intense volatility. At this stage, investing in the storage sector should not rely solely on faith in the "AI story" but must be grounded in hard fundamentals such as HBM capacity progress, LTA signing pace, and customer order visibility to assess risk-reward ratios.