Asia Market Wrap 13 October: The Kospi Sinks 5.46 Percent in Its Worst Day Since August

By The Edge Research Team

Seoul’s Kospi sank 5.46 percent on Tuesday, its worst day since mid-August, as reported progress by China’s memory chipmaker CXMT set off a selloff in the region’s semiconductor stocks. Tokyo returned from its holiday to a split verdict, the Nikkei 225 down 1.82 percent while the Topix edged higher, and Taipei’s Taiex lost 1.95 percent. Brent traded 1.66 percent below Monday’s settlement at 104.88 dollars a barrel by the 10:03 GMT reading.

A sidecar in Seoul as the chip trade cracks

The Kospi fell 348.89 points to 6,035.35 in a fifth straight decline, opening 3.1 percent lower and falling far enough that the Korea Exchange triggered a sell-side sidecar during morning trading, as Yonhap reported it. Samsung Electronics lost 7.39 percent to 232,000 won and SK hynix 10.09 percent to 1.44 million won, with a Kiwoom Securities analyst pointing to concerns over OpenAI’s revenue and the completion of the two chipmakers’ share buybacks; decliners outnumbered advancers 628 to 246 on volume of 399.87 million shares worth 26.79 trillion won. Foreigners sold a net 4.51 trillion won of Seoul shares, while institutions bought 1.69 trillion and individuals 2.23 trillion. The won weakened to 1,345.1 per dollar by the 15:30 reading from 1,335.1, and bonds caught the safety bid, the three-year yield down 6.4 basis points at 3.857 percent. President Lee Jae Myung told a cabinet meeting that South Korea “has no choice but to raise its interest rates” to narrow the gap with a Federal Reserve holding at 3.75 to 4.00 percent against the Bank of Korea’s 3.00, remarks Reuters called an unusual political intervention in a decision that is legally the central bank’s.

The trigger ran wider than Seoul. Reuters’ markets report had reports of rapid technology progress at ChangXin Memory Technologies feeding concern that China’s AI players will contest the memory market sooner than assumed, with Broadcom’s chief executive likening some flows into the AI sector to “casino gambling”; MSCI’s Asia-Pacific index outside Japan fell more than 2 percent to its lowest since late July, and SoftBank dropped 8 percent in Tokyo. TSMC’s 1.8 percent fall took the Taiex down 1.95 percent in a fourth straight decline, and Shenzhen’s chip-heavy Component index slipped 0.25 percent against a 0.10 percent rise in Shanghai.

Tokyo splits and the oil bid fades

Tokyo’s return from the Sports Day holiday produced the day’s strangest board: the Nikkei 225 fell 1,253.40 points to 67,777.52, dragged by its technology heavyweights, while the broader Topix added 0.14 percent to 4,110.67, a split that marks the selling as a narrow index trade rather than a market-wide retreat. Wholesale prices rose 6.8 percent in the year to September, slower than August and below forecasts, and Bank of Japan Governor Kazuo Ueda told parliament that underlying inflation “has now come quite close to 2%”, language that keeps a rate rise in play at this month’s meeting even as a Sompo Institute economist argued the bank can wait until December. Elsewhere the day’s relief came from the oil tape and, in Mumbai, from the technology trade itself: the Nifty 50 rose 1.60 percent to 22,721.95 on the exchange’s own figures, the day’s strongest board, with 46 of its 50 constituents higher and the exchange’s information technology index up 5.22 percent with all ten of its members, a reminder that the repricing is about memory chips, not software. Brent’s retreat below 105 dollars lifted the other importers, Hong Kong’s Hang Seng up 0.30 percent in a third straight gain and Singapore’s Straits Times up 0.28 in a second, even as Reuters reported, citing people familiar with the plans, that the Blackstone-backed data-centre operator AirTrunk had delayed its Singapore REIT listing into the AI selloff. Sydney’s S&P/ASX 200 closed all but flat, up 0.70 points.

Top gainers

Closes of Tuesday 13 October 2026, ranked by change against Monday’s closes as published; the Topix row is measured against its 9 October close across the Sports Day holiday, and the Nifty row is the exchange’s own figure. Run lengths are counted against our published closes.

Top losers

Closes of Tuesday 13 October 2026, ranked shallowest to deepest against Monday’s closes as published; the Nikkei row is measured against its 9 October close across the holiday.

Commodities and currencies

Intraday quotes at 10:03 GMT, in fixed order; snapshots, not settlements. The gold, Brent and WTI changes are against Monday’s settlements of 4,190.60, 106.65 and 93.74 dollars, as published in our Commodities Wrap of 12 October 2026 and resolved in our US Market Wrap the same evening.

Why it matters: The region’s AI trade just failed its first stress test of the quarter, and the failure was selective: the markets that make the chips fell, the markets that buy the energy and move the goods did not, and inside Tokyo the gap between a chip-heavy index and the broad market told the same story in one city. A sidecar in Seoul alongside a Topix gain reads less like a panic than a repricing of one crowded trade, and the won’s slide beside a bond-market rally suggests the selling sat in Korean equities rather than in Korea at large. With the IMF warning in Bangkok that the global expansion now leans on a narrow technology base, the session read like a rehearsal of exactly that concentration risk.

Outlook: Our Middle East wrap follows after the regional closes. Four of the six largest US lenders, JPMorgan Chase, Goldman Sachs, Citigroup and Wells Fargo, report later today, and Wednesday brings the US consumer price report, with futures markets pricing an 80.6 percent chance of a Federal Reserve hold this month per the CME’s gauge cited by Reuters, and China’s September inflation data the same day, as published in our Week Ahead of 11 to 17 October. Tonight’s commodities wrap reads the session’s settlements on the same December and November crude series.

How these wraps are prepared: Methodology.

Sources: CNBC, NSE India, Yonhap, Reuters, The Edge.

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