SKHX Drops 13.6% as Broadcom's Soft AI Guidance Triggers a KOSPI Circuit Breaker

The Catalyst Came From San Jose, Not Seoul

This was not a Korea story at the source. After Wednesday's close, Broadcom reported and guided Q3 AI semiconductor revenue to roughly $16 billion against a ~$17.2 billion consensus — about 7% light, with full-year AI guidance near $56 billion versus the $57.6 billion the Street wanted. The print itself wasn't bad; AI revenue is still set to grow over 200% year-over-year. But after a year of the AI-memory trade pricing in nothing but acceleration, a single guide that merely *meets* instead of *blows out* is enough to break the reflexive bid. Broadcom dropped roughly 13–14%, dragging AMD and Intel with it and sending the Philadelphia Semiconductor Index down over 5%. Korea opened into that.

A Circuit Breaker Eight Minutes After the Bell

Seoul did not ease into it. The KOSPI gapped down 3.66% at the open and was through 8,100 within fifteen minutes, and the Korea Exchange tripped a sell-side circuit breaker at 9:08 a.m., halting program sell orders for five minutes after KOSPI 200 futures fell 5%. SK Hynix common fell 8.18% to ₩2.11 million; Samsung dropped over 6%. The leverage products did what they always do at the top — single-stock leverage ETFs plunged around 14% as the two names that *are* the index unwound in tandem. With Samsung and SK Hynix now over 40% of the KOSPI's weight, there is no diversification left in this tape; a chip-sentiment shock is an index shock.

Foreigners Were Already Leaving

The Broadcom guide didn't create the selling pressure so much as light the fuse on a positioning unwind that was already underway. Foreign investors have net sold on the order of $22 billion in Korean equities since May, with SK Hynix alone accounting for roughly $12 billion of that. The valuation argument — KOSPI trailing P/E in the low 30s against a far cheaper history — has been the quiet whisper under this entire rally, and last month's 'citizen dividend' political-risk scare already gave foreign desks one excuse to ring the register. Broadcom handed them a fundamental one. None of this contradicts the bull case structurally: Goldman Sachs lifted its SK Hynix 12-month target toward ₩3.5 million on June 1, arguing memory tightness runs through 2028. This is a positioning flush inside an intact supply story, not a thesis break.

Why SKHX Cut Deeper Than the Stock

SKHX prints $1,325, down 13.60% over 12 hours — a wider move than the ~8% the underlying took in the Seoul cash session. Two things drive the wedge. First, the 12-hour perp window straddles the record-high leg SKHX had run to since the May citizen-dividend round trip, so the percentage is measured off a higher base than the Korean close. Second, SKHX is an oracle product converting the KRW share price to USD at the prevailing USD/KRW rate, so any won weakness on a global risk-off day stacks on top of the equity move rather than offsetting it. The signal to respect is that the perp is now retracing the entire breakout leg it built after May 15's reversal — the same round-trip behavior, one rung higher. Whether $1,325 holds depends less on Korea than on whether the AI-capex narrative finds a floor after the first guidance that wasn't a beat-and-raise.