Asian Chip Stocks Surge on Explosive AI-Led Rebound; KOSPI Rallies 17% as Circuit Breakers Trigger

Asian equities posted a historic comeback on Friday, led by a violent rally across South Korean and Japanese semiconductor names.

Reversing three consecutive sessions of heavy liquidation, the benchmark KOSPI index soared as much as 17% intraday—marking its largest single-day gain on record—and triggering a buy-side "sidecar" trading halt.

The sudden reversal follows a strong overnight session on Wall Street, where blowout cloud results from Microsoft and Amazon reignited global optimism over AI infrastructure spending.

Key Market Highlights

South Korea (KOSPI): After opening up 1.1%, the index accelerated vertically to break above 6,400 points.
- Samsung Electronics: Jumped nearly 25% intraday.
- SK Hynix: Surged nearly 28%, touching a peak intraday gain close to 30%.

Japan (Nikkei 225): The index expanded gains past 5%.
- Advantest: Soared over 14%.
- Tokyo Electron & Renesas: Gained over 11% and 10%, respectively.
- SoftBank Group: Vaulted over 15%, fueled by its major stake in Arm Holdings.

The Catalyst: Wall Street's Record CapEx Conviction

The regional rally was ignited by a massive short-squeeze and fundamental rotation in U.S. tech overnight:

iShares Semiconductor ETF (SOXX): Surged over 8% in Thursday's regular session.
Microsoft (MSFT): Soared 15.51% to log a historical $449.7 billion single-day market cap gain—the largest in Wall Street history—after Azure growth beat estimates.
Amazon (AMZN): Advanced over 9% in after-hours trading on strong Q2 cloud performance.
U.S. Memory & AI Winners: SanDisk surged 25.99%, Micron jumped 18.36%, and SK Hynix ADRs gained 17.52%.

Sentiment around SK Hynix was further bolstered by executive confidence: regulatory filings revealed that SK Group Chairman Chey Tae-won personally purchased 3,620 shares of SK Hynix (valued at ~$3.31 million) ahead of Thursday's U.S. open.

Structural Context: Unwinding Forced Liquidations

The sharp rebound represents a dramatic relief rally after weeks of severe unwinding.

Extreme Volatility: Year-to-date, extreme swings have made circuit breakers routine on the Korea Exchange, triggering market-wide halts 9 times and sidecar mechanisms over 40 times.
Leverage ETF Crackdown: Critics have blamed single-stock leveraged ETFs for compounding downside cascades. In response, South Korean regulators announced strict new measures starting July 31—including a 20% portfolio cap on single-stock leveraged ETFs, higher cash deposit requirements (raised to 30 million won), and a temporary freeze on new leveraged listings.
Analyst Outlook: Industry experts note that while retail leverage caps help dampen mechanics, they do not restrict underlying fund leverage directly.

"The violent sell-off in SK Hynix and the broader semiconductor sector marked a short-term bottom for AI equities," noted Dan Niles, Founder of Niles Investment Management. "The liquidation wave was driven primarily by passive forced deleveraging rather than a collapse in industry fundamentals."