The iShares Semiconductor ETF moved sharply lower in early U.S. trading, sliding 6.1% to $614.82 after a broad technology downturn originating in Asia spilled into U.S. chip stocks.
The rout was anchored by an historic drop in South Korean semiconductor names. South Korea's KOSPI plunged 9.99% on June 23, a fall severe enough to trigger a market-wide circuit breaker that halted trading for 20 minutes. Major Korean chip companies were deeply affected, with Samsung Electronics falling about 12.3% and SK Hynix dropping about 12.5% as foreign investors sold billions of dollars of shares.
Reports that SK Hynix is slowing its AI memory expansion sharpened investor unease, undermining confidence in the global AI hardware buildout thesis and prompting selling across related stocks. That news combined with weaker sentiment among some high-profile market participants to accelerate the decline.
Prominent tech investor Dan Niles publicly trimmed his semiconductor positions and warned that the AI trade is likely to hit a near-term "speed bump." He highlighted doubts about whether hyperscale cloud providers can earn sufficient returns on the massive AI infrastructure investments they are making, and pointed to an emerging trend of companies routing workloads to cheaper AI models to rein in costs.
Adding to the pressure on U.S. memory stocks, Micron shares tumbled sharply heading into the semiconductor maker's scheduled fiscal third-quarter earnings report. The sell-off in Micron was driven by pre-earnings profit-taking, a broader pullback in AI-linked names and renewed worries about corporate spending on AI infrastructure. Investors are treating Micron's upcoming results as a de facto report card for the broader memory and AI semiconductor sector.
Market moves were not limited to the United States and South Korea. In Europe, the Stoxx 600 Technology index fell 3.2%, with chipmaker STMicroelectronics and Dutch semiconductor equipment maker ASMI each off by more than 7% during the session.
Heightening investor caution were indications of a potentially more hawkish U.S. Federal Reserve. Fed funds futures were pricing in a roughly 75% probability of a rate hike by September, a dynamic that supports a higher-for-longer interest rate outlook and can make richly valued technology stocks more vulnerable.
Analysts and market commentators framed the pullback as profit-taking in a sector that had run hard, rather than evidence of widespread deterioration in underlying business fundamentals. Still, with the ETF trading near its 52-week high of $655.95 heading into the session, the combination of cross-border contagion, hawkish rate signals and pre-Micron nervousness was sufficient to produce a sharp reversal in chip-related assets.
Intraday market data in parts of the session also showed Micron down 8.81% and the SOXX ETF off about 5.55% on certain quotes, underscoring the volatility sweeping through semiconductor names during the sell-off.
Summary: A dramatic sell-off in South Korean chip stocks, concerns over SK Hynix's AI memory expansion plans, bearish commentary from a prominent tech investor and pre-earnings weakness in Micron combined to push the iShares Semiconductor ETF sharply lower in morning U.S. trading.