The Korea Composite Stock Price Index (KOSPI) extended losses on Thursday, 8 October 2026, slipping 54.22 points, or 0.8 percent, to 6,749.68 as of 11:20 am local time, dragged by elevated oil prices that are fanning fresh inflation concerns and casting doubt on the trajectory of US Federal Reserve interest rate policy.

What Triggered the Slide

The benchmark index opened marginally higher — up 0.07 percent — before reversing course almost immediately, tracking an overnight Wall Street pullback. The Dow Jones Industrial Average fell 0.66 percent on Wednesday, while the tech-heavy Nasdaq Composite declined 0.22 percent. Analysts point to rising crude prices as the principal catalyst, with higher energy costs threatening to keep consumer inflation elevated and prompting fears that the Fed may be compelled to raise rates further before year-end.

Institutional and Foreign Selling Weigh on Sentiment

Selling pressure was concentrated among institutions and foreign investors. Institutions offloaded a net 457.28 billion won (approximately US$342 million) worth of shares, while foreigners sold a net 666.37 billion won. Retail investors stepped in on the other side, absorbing a net 834.66 billion won in stocks, though not enough to arrest the decline.

Large-Caps: Mixed Picture

Blue-chip performance was uneven. Market giant Samsung Electronics shed 0.56 percent, while top carmaker Hyundai Motor fell sharply by 3.05 percent. Defence conglomerate Hanwha Aerospace was among the session's biggest losers, dropping 5.86 percent, and shipping firm HMM declined 2.57 percent. On the positive side, chipmaker SK Hynix advanced 1.33 percent and battery manufacturer Samsung SDI climbed 3.74 percent, buoyed by continued optimism around the global semiconductor upcycle.

Won Steady; Current Account Surplus Near Record

The Korean won was trading at 1,337.35 won per US dollar as of 11:20 am, firming slightly by 1.65 won from the previous session's close. Separately, the Bank of Korea (BOK) on Thursday reported that South Korea's current account surplus reached US$46.1 billion in August — the second-highest figure on record — up US$4 billion from July and a dramatic US$36.2 billion jump compared with August 2025. The surplus has remained above the US$40 billion mark for three consecutive months, following US$42 billion in July and a record US$49.73 billion in June. Cumulatively, the January–August 2026 current account surplus totalled US$279.2 billion, nearly quadrupling from the same period a year earlier.

BOK Outlook and What's Next

A BOK official said the August surplus figures were 'in line with the forecast,' adding that the annual current account surplus is on track to reach the projected US$450 billion. The juxtaposition of a record-high current account surplus with a sliding equity market underscores the divergence between South Korea's robust export engine — driven largely by semiconductors — and the investor caution stemming from global inflation and rate-hike anxiety. Markets will closely watch the next US Fed communications and any fresh movement in crude oil prices for directional cues.