The global selloff in semiconductor stocks reached Asia on Thursday, hitting the region's memory-chip champions hardest.

In early Seoul trading on July 2, Samsung Electronics fell more than 7% and SK Hynix more than 9%, CNBC reported, dragging down South Korea's benchmark Kospi index. SK Square, SK Hynix's largest shareholder, dropped more than 10%. The trigger was an overnight slump in U.S. chip stocks on the tech-heavy Nasdaq, which rippled straight into Asia's supply chain at the open. (Markets often "import" moves this way: when U.S. shares of a sector fall after Asian markets have closed, Asian investors reprice their own related stocks the next morning.)

A supply chain sells off together

The damage extended across the region's chip ecosystem. In Japan, memory maker Kioxia and materials and equipment suppliers such as Ibiden fell sharply, according to Investing.com, though Japan's broader Nikkei 225 held up better than the Kospi thanks to strength elsewhere. The common thread was clear: this was a sector selloff, not a country one — investors were cutting exposure to chips wherever they held them.

Why chips are so exposed

Semiconductors, especially the memory chips used to train and run AI systems, have been among 2026's biggest winners — and among its most crowded trades. Prices for the memory that Samsung and SK Hynix make have surged on AI demand, lifting their shares and making the sector a huge share of regional indexes. That concentration cuts both ways: when sentiment turns, the same stocks that led the market up lead it down, and the move is amplified because so many investors are positioned the same way. Analysts have warned for weeks that the AI-chip trade looked stretched and overbought.

Two catalysts have fed the caution. Reports that Meta may build a business selling its own spare AI computing power stirred worry that big tech's chip spending could become more disciplined — a concern Boursel covered when Meta's stock jumped on the news. And reports that Apple is evaluating memory chips from Chinese suppliers weighed on sentiment toward Korea's memory giants, per Investing.com. Both touch the same nerve: any hint that the customers driving the AI boom might spend less, or buy elsewhere, hits chipmakers first.

What it is — and isn't

This is best understood as a rotation and a repricing, not a verdict on the AI story. "Rotation" means investors shifting money out of one crowded area — here, chips — into others seen as cheaper or less exposed. Sharp, fast moves are typical when a heavily owned trade unwinds, and Korean chip shares have swung violently in both directions in recent sessions. Boursel does not forecast where the market goes next; the analysts cited here are describing what drove the selling, not predicting the bottom.

Why it matters

For global investors, the episode is a reminder of how concentrated the world's markets have become in a handful of AI and chip names — so a stumble in that group moves entire national indexes. For Korea and Japan, whose exchanges are dominated by chipmakers and their suppliers, it means outsized volatility tied to a single global theme. And for the broader AI trade, it shows how sensitive these richly valued stocks now are to any sign — a Meta strategy shift, an Apple sourcing report — that the extraordinary spending underpinning them might cool. The memory boom that lifted these shares hasn't reversed; but Thursday was a sharp lesson in how quickly a crowded trade can wobble.