South Korea's 3% KOSPI Slide Deepens as SK Hynix Drops 7% Again

Liquidity stress amplified the KOSPI collapse

This was a liquidity event first and a fundamentals story second. Across the two-session collapse, Seoul saw as much as $2.18 trillion wiped from its equity market. That scale of value loss points to a crowded AI trade losing buyers quickly, with margin exposure making the decline sharper.

KOSPI weakness flowed through index weight

The damage concentrated in the biggest names. On Tuesday, the KOSPI dropped 500.47 points, or 7.41%, triggering sidecar trading curbs as the selloff widened. The next day's additional decline deepened that pattern. Because SK Hynix and Samsung are major index constituents, their weakness spread well beyond the semiconductor sector.

Volume mattered as much as price. Reuters said Wednesday's rout came amid light trading and left leveraged retail investors reeling as brokers forcibly closed losing positions. In that setup, weak participation can look more like forced de-risking than organic demand.

SK Hynix showed why record profit was not enough

After the prior session already reset expectations, SK Hynix became the clearest test of whether AI-memory earnings could still outrun investor ambition.

Record profit still missed the market's higher bar

On paper, the quarter was huge. SK Hynix said quarterly operating profit soared more than sixfold to a record high. But the results still fell short of lofty expectations. Delays in some advanced-product shipments limited price gains in DRAM, which meant the company did not fully prove that AI demand was translating into the earnings visibility investors wanted.

That is why "better than before" was not enough. SK Hynix said major customers are still requesting more memory supply, but the selloff reflected concerns over AI infrastructure financing and the possibility that hyperscalers could slow spending for a period. The debate is shifting away from current profitability and toward the durability of AI capex.

Supply agreements offered stability, not a clean catalyst

SK Hynix also said it has signed about 10 long-term supply deals aimed at smoothing demand volatility. That should help visibility, but the market treated it as a defensive step rather than a new upside catalyst. If anything, the emphasis on contracts reinforced the concern that demand still feels less predictable than investors had hoped.

The more immediate signal was price action in the company's U.S.-listed shares, which closed at $143.02, below their initial public offering price of $149. In a business where cycles can turn quickly, investors appear to want cleaner proof that shipments and pricing can keep pace with expectations.

What would change the read on the selloff?

Near term, the cautious view still looks easier to defend. In the earlier AI unwind, Samsung and SK Hynix fell as much as 9.5% and 10.9%. The market impact has been especially severe because those two companies account for more than half of the KOSPI's weighting. When the stocks that carry the most index weight lead a decline, broader market support becomes much harder to find.

Reuters also linked the selloff to concerns about China competition and fears that AI infrastructure spending could pause. Added uncertainty around Nvidia's potential role in financing parts of the AI build-out strengthened that read. For now, the move looks like a mix of leverage unwinding, weaker sentiment, and fresh doubts about how sustainable AI spending really is.

What matters next is whether leadership stabilizes after upcoming hyperscaler earnings and the Fed decision. If Samsung and SK Hynix stop leading the downside, the move is more likely to look like a forced reset than the start of a deeper trend break.