[Analysis] US Stock Market Hits Record Highs: Tech Rally

US Stock Market Reaches Record Highs Driven by Tech Stocks

As of the market close on May 26, 2026 (local time), the US stock market saw its major indices hit new record highs, fueled by strong conviction in artificial intelligence (AI) and semiconductor infrastructure investments. The S&P 500 index rose 0.61% to close at 7,519.12, while the tech-heavy Nasdaq Composite climbed 1.19% to end at 26,656.18 (Sources: Maeil Business Newspaper, Newspim, as of May 27, 2026).

Notably, the Philadelphia Semiconductor Index surged 5.53%, leading the market's strong upward momentum. Conversely, the Dow Jones Industrial Average fell 0.23% to 50,461.68 due to weakness in the energy sector, highlighting a clear sectoral divergence within the US stock market.

Micron Surpasses $1 Trillion Market Cap Amid AI Infrastructure Boom

The primary driver behind this US stock market rally was undoubtedly the explosive growth in the semiconductor sector. Micron Technology's surge, in particular, led the broader market sentiment. Following a massive price target upgrade by UBS from $535 to $1,625, Micron's stock price surged by roughly 19-21% in a single day, pushing its market capitalization past the $1 trillion mark for the very first time (Source: Joseilbo, as of May 27, 2026).

• HBM and Data Center Demand: Strong market expectations regarding high-bandwidth memory (HBM) and the continued expansion of AI data centers directly translated into robust capital inflows.
• Sympathetic Rallies: Other data storage and memory semiconductor companies like Western Digital and Seagate also saw their stock prices rise, reinforcing the broader semiconductor rally.

Market Outlook and Implications for Investors

Despite ongoing geopolitical risks, including conflicts between the US and Iran, the US stock market is currently dominated by a strong fundamental belief that massive capital expenditures for AI infrastructure will inevitably translate into structural earnings growth for tech companies. Capital is heavily betting on long-term technology-driven growth rather than reacting to short-term external noise.

Ultimately, this market milestone is rooted in concrete upward revisions of corporate earnings outlooks rather than mere speculation. Investors should look beyond short-term directional plays and consider a sophisticated portfolio rebalancing strategy, weighing core AI infrastructure companies with proven revenue generation against historically lagging value sectors.