Why Asia-Pacific Chip Markets Traded Mixed on July 3: Anthropic-Samsung Talks vs. AI Overcapacity Fears

Asia-Pacific markets traded mixed on Friday, July 3, 2026, as a two-day semiconductor selloff showed a clear regional divergence: South Korean chip stocks partially recovered on the back of a report that Anthropic held early talks with Samsung Electronics about a custom AI chip, while Japanese chip stocks remained under pressure from lingering worries about AI infrastructure overcapacity that triggered the Thursday selloff on Wall Street.

The Thursday Rout (July 2)

Asian semiconductor stocks tumbled on Thursday after Meta Platforms revealed plans to develop a business selling access to AI computing power, stoking fears that aggressive capital spending by big tech companies could outpace real demand . In South Korea, Samsung Electronics plunged more than 7% and SK Hynix sank over 9% at the open, wiping out billions in market value as the tech-heavy Nasdaq Composite slumped overnight . Samsung ultimately closed 9.06% lower at 286,000 won, while SK Hynix dropped 14.57% to 2,187,000 won . The broader KOSPI index fell nearly 6% . In Japan, the Nikkei 225 lost 2.5% to close at around 59,476 points, dragged lower by chip-related names . Kioxia Holdings tumbled 14% after a blistering rally that had sent the stock up more than 650% year-to-date .

Friday, July 3 — Mixed Trading with a Clear Divergence

South Korea — Partial Recovery. News broke late Thursday/Friday morning that Anthropic, the developer of the Claude AI model, had begun early-stage work on a custom AI chip and was discussing a potential manufacturing partnership with Samsung . The Information reported that Anthropic is specifically considering Samsung's 2-nanometer manufacturing process and advanced packaging facilities . This provided a positive catalyst for Samsung shares, helping the KOSPI lead a regional rebound in chip stocks . The recovery followed weeks of severe volatility: the KOSPI had plunged 10% on June 23, triggering a market-wide circuit breaker on the Korea Exchange .

Japan — Continued Weakness. Japan's Nikkei 225 fared worse on Friday. Chip-related stocks in Japan had already fallen 3.9% in early June when the AI rally first lost steam , and the Friday session saw continued selling pressure on Japanese semiconductor names without a comparable positive catalyst. SoftBank Group, a major tech conglomerate, had been down around 14% on June 25 after reports that OpenAI might develop its own AI chips in partnership with Broadcom . The Nikkei 225 had also reached a record high of 71,053.49 on June 18 , making the subsequent selloff more pronounced.

Anthropic-Samsung Talks: The Key Catalyst

The Anthropic-Samsung talks are the most important factor explaining the intra-regional divergence on Friday. Key details from sources:

• Early-stage talks: Anthropic has begun early-stage work on developing its own AI chips and is discussing a potential manufacturing partnership with Samsung . The chip's use, performance specifications, and server integration have not been decided .
• Strategic investment: Samsung Electronics, SK Hynix, and Micron all participated in Anthropic's $65 billion Series H funding round in late May, which valued Anthropic at $965 billion . Samsung was named a "strategic infrastructure partner" .
• Logic-chip advantage: Among the three chipmakers that invested, Samsung is the only one that manufactures logic chips (the type that run AI computations), positioning it to potentially win foundry orders from Anthropic .
• HBM4E momentum: Samsung had already shipped samples of its 12-layer HBM4E memory chips to key customers in early June, strengthening its AI chip credentials .

Anthropic told TechCrunch that "a diverse set of hardware configurations, including chips from Google, Amazon, and NVIDIA, will continue to play an important role in Anthropic's compute strategy," but declined further comment on the Samsung partnership .

Broader Context: U.S. Chip Declines and AI Demand Concerns

The Asia selloff was part of a wider global rotation out of tech and AI-linked stocks. The Philadelphia Semiconductor Index was tracking toward its worst week since March 2025 . Deutsche Bank strategists noted that tech weakness extended from the Magnificent 7 and Apple into Asian markets, weighing on risk sentiment and U.S. equity futures . The core worry was that AI infrastructure spending might be peaking, with investors increasingly concerned that valuations had outrun fundamentals . On June 23, the tech rout deepened globally: Nvidia and Tesla fell sharply, the KOSPI plunged 10%, and the Nasdaq fell nearly 2% .

Year-to-Date Performance Note

The available evidence does not contain precise H1 2026 percentage returns for the KOSPI and Nikkei 225 as of July 3. What is clear: both indices had reached record highs in mid-June, with the KOSPI surging on AI enthusiasm to become one of the world's best-performing major equity markets before the June-July tech rout erased gains . The KOSPI was the more volatile of the two, suffering a 10% single-day plunge on June 23 that triggered a circuit breaker , while the Nikkei 225 experienced more moderate but sustained declines. The KOSPI had also fallen 8% on June 7, with chipmakers SK Hynix sliding 5.4% and Samsung 2% .

Key Stocks at a Glance

South Korea:

• Samsung Electronics: fell 9.06% on July 2 to 286,000 won; partially recovered on July 3 after Anthropic news
• SK Hynix: fell 14.57% on July 2 to 2,187,000 won; partially recovered on July 3
• SK Square (largest SK Hynix shareholder): fell 13.2% on July 2

Japan:

• Kioxia Holdings: fell 14% on July 2; continued weak on July 3
• SoftBank Group: down ~14% on June 25; remained pressured
• Advantest: fell 11% in earlier rout in November 2025

Key caveat: The available evidence does not provide exact closing prices for all stocks on July 3. The directional moves are clear from source reporting.