Asia handed the US a genuine risk-off tape — a weekend US-Iran escalation and an oil shock detonated the memory-chip complex, and Korea circuit-broke.
KOSPI closed -8.95% at 6,807, tripping a market-wide circuit breaker, with SK Hynix -15.37% (its worst day on record, deeper than 2008) and Samsung -10.7% leading a memory-cycle-peak unwind amplified by leveraged single-stock ETFs. The Nikkei fell 1.76% back below 68,000 to ~67,242 as Tokyo chip names (Kioxia -12%, Tokyo Electron) tracked Wall Street's rout. The trigger: US forces struck 170-plus Iranian targets in 48 hours, shattering a four-week ceasefire, with a contested claim that the Strait of Hormuz was closed driving crude higher.
USD/JPY pushed to 162.4 — not classic carry-off yen strength but an oil-import shock plus a dollar haven bid, so risk-off is expressed through equities and crude, not the yen. The read-through is negative for SOX and QQQ into the cash open: the Korean memory crash pipes straight into Micron and the HBM/AI-capex complex via the same-cycle channel. Note the decouple — Hang Seng held +0.2% and CSI 300 fell only 1.8%, with China trading its own book rather than the global chip panic.
The risk: any Iran/Hormuz de-escalation headline or a crude reversal flips this fast — the selloff is geopolitical, not fundamental, so a restored ceasefire would let semis snap back. Watch this week's US big-tech earnings as the pivot, and respect that a valuation washout in Korean chips could mark capitulation rather than fresh trend.