Bottom line: verified earnings met an oversold market
The simultaneous rise in U.S. and Korean AI-related shares does not mean every company became more valuable overnight. Microsoft showed that AI infrastructure spending was feeding Azure revenue and profit, while Lam Research reported record semiconductor-equipment results tied to AI demand. Bargain buying and short covering then amplified the move after a severe selloff.
The U.S. figures below are July 30 closing values. Korea reflects the next session, but the KOSDAQ data are an intraday snapshot at 11:14 a.m. KST on July 31, 2026, not a close.
| Market or stock | Verified move | Reading |
|---|---|---|
| Nasdaq Composite | +2.8% to 25,122.18 | AI and chips rebounded after a large correction |
| Microsoft | +15.5% | Azure growth strengthened the AI-return case |
| Micron / Lam Research / AMD | +18.4% / +18.0% / +13.0% | Memory, equipment, and compute recovered together |
| KOSDAQ | +8.83% to 701.72 intraday | Technical rebound after three steep down sessions |
| TES / TSE | +30.00% / +29.94% intraday | Buying concentrated in equipment and testing |
| TechWing / Jusung Engineering | +23.51% / +22.79% intraday | High-beta exposure to AI memory and process tools |
U.S. closes come from AP; Korean index and stock snapshots come from Naver Finance's exchange-data relay and can change during the session.
1. Microsoft answered the AI monetization question
Microsoft's official FY2026 Q4 release reported quarterly revenue of $90.0 billion, up 18% year over year. Microsoft Cloud reached $59.3 billion, up 27%, and Azure and other cloud services grew 43%. Full-year Azure revenue passed $100 billion for the first time, while Microsoft 365 Copilot exceeded 30 million paid seats.
The important signal was not spending alone but its connection to cloud demand and paid adoption. AP recorded a 15.5% Microsoft gain, its best day in nearly 18 years. Meta, however, fell 8% as weaker profit and a higher investment-spending floor revived cost concerns. This was therefore a selective rally rewarding clearer returns, not proof that every AI business had improved.
2. Lam Research supplied evidence from the semiconductor chain
Lam Research's release showed June-quarter revenue of $6.72 billion, 15.1% above the prior quarter. The company called revenue, operating margin, and EPS records and guided to a September-quarter revenue midpoint of $8.1 billion. Korea represented 20% of June-quarter revenue.
That supports the view that data-center demand is reaching memory and etch, deposition, and inspection equipment—not only GPU designers. AP recorded gains of 18% for Lam Research, 18.4% for Micron, and 13% for AMD.
3. KOSDAQ's prior losses magnified the rebound
The daily KOSDAQ series shows declines of 7.72% on July 28, 6.12% on July 29, and 2.70% on July 30—about 15.7% cumulatively from the preceding base. The July 31 intraday rise followed that compression. The July 28 drop had triggered sell-sidecars as U.S. chip weakness, concern about Chinese memory competition, and global risk aversion converged.
In a market that has moved this far this quickly, a sentiment reversal can force short covering and mechanical rebalancing. KOSDAQ's July 31 risers were concentrated in semiconductor equipment, testing, and memory-related companies including TES, TSE, LTC, TechWing, Jusung Engineering, FADU, Jeju Semiconductor, and Wonik IPS. It is more accurate to call this a high-beta AI-infrastructure and semiconductor rebound than a universal rally in pure AI software.
What remains unproven
- Many Korean names issued no new company-specific disclosure. U.S. earnings sympathy is not evidence of fresh orders for each business.
- One day does not establish a trend reversal. Before the rebound, Nasdaq was 9.8% below its recent record, and KOSDAQ had not recovered its preceding losses.
- Rate and inflation risk remains. AP placed the U.S. ten-year Treasury yield at 4.67%, a potential valuation headwind for growth stocks.
- Korean figures are intraday; closing returns and rankings can differ.
What to watch next
- Whether later big-tech earnings balance AI capital expenditure with cloud revenue
- Durability and margin implications of Azure's 43% growth
- Whether Lam's $8.1 billion midpoint converts into orders and shipments
- Continued foreign and institutional cash buying in Korean semiconductors
- New disclosures and earnings for the fastest risers, separating thematic sympathy from fundamentals
This article explains verified public results and market data. It is not investment advice or a recommendation to trade any security.