KOSPI falls nearly 2% as bond yields and Samsung earnings weigh on Seoul shares

South Korea’s KOSPI fell 1.98% in Seoul on Wednesday, Oct. 7, 2026, closing at 6,803.90 as major technology shares declined for a second straight session. The drop came amid concern over bond yields and ahead of Samsung Electronics’ preliminary earnings announcement, leaving investors watching both borrowing costs and results from the country’s largest listed companies.

The benchmark index lost 137.49 points from its previous close, according to Yonhap News Agency and SBS News. Yonhap reported that the decline followed a 0.89% fall on Oct. 6, when the KOSPI closed at 6,941.39. Wednesday’s retreat therefore added to losses already recorded in the preceding session.

How the KOSPI traded on Oct. 7

SBS, citing the Korea Exchange, said the index opened at 6,864.25, down 1.11% from the previous close. It briefly recovered before turning lower and extending its losses. That sequence matters because the final decline was larger than the initial fall: a short rebound during the day did not hold through the close.

Samsung Electronics fell 1.29% to 268,500 won, while SK hynix dropped 2.82% to 1.72 million won, Yonhap reported. SBS gave the same percentage declines for both chipmakers. Other large technology-linked shares also lost ground: Yonhap put SK Square, the parent of SK hynix, down 1.64%, and Samsung Electro-Mechanics down 4.24%. The weakness in these widely followed companies was a prominent part of the day’s market move.

Bond yields and earnings caution

Both reports described rising yields as a concern for investors, but their accounts of market pressure are interpretations, not proof that a single factor caused the fall. Yonhap said bond yields had climbed to multidecade highs. SBS reported that the yield on the 10-year U.S. Treasury rose above 5.3% and that oil prices had rebounded. Its figures put U.S. West Texas Intermediate futures above $90 a barrel and Brent crude above $101 by 3:45 p.m. Seoul time.

Yonhap quoted Daishin Securities analyst Lee Kyung-min as saying the KOSPI faced renewed pressure amid rising international oil prices and U.S. Treasury yields. He also said investors were taking a wait-and-see approach before Samsung Electronics’ preliminary earnings report, scheduled for Thursday, Oct. 8. SBS likewise linked caution about that announcement to market sentiment. The company’s results and any subsequent market response were still unknown in the two reports.

SBS also reported Lee’s assessment that LG Electronics’ third-quarter operating profit had fallen 24.8% below expectations, adding to concern about forthcoming corporate results. That observation describes the caution cited by an analyst; it does not establish what Samsung’s figures will show. Yonhap noted that Seoul’s decline came despite overnight gains in U.S. shares: it put the Dow Jones Industrial Average up 0.49% and the Nasdaq composite up 0.45%, with the Nasdaq reaching a record high.

Who bought and sold shares

Yonhap reported that foreign investors sold a net 2.59 trillion won of KOSPI shares and institutions sold a net 672.7 billion won. Individuals bought a net 2.56 trillion won. SBS also reported net selling by foreign and institutional investors and net buying by individuals, but gave slightly different totals: 2.6087 trillion won, 668.4 billion won and 2.557 trillion won, respectively. Those figures are kept with their sources because the published totals do not match exactly.

SBS identified another change in buying activity. It said other corporations bought a net 709 billion won of shares, below a recent daily average of about 1.6 trillion won, as treasury-stock purchases by Samsung Electronics and SK hynix slowed. According to SBS, Samsung had completed its planned 15 trillion won purchase, while SK hynix had completed about 80% of its scheduled volume. This provides context for the trading flows without establishing how much the reduced buying affected the index.

The currency and bond figures show that the session was not a uniform move across South Korean markets. The won stood at 1,340.4 per U.S. dollar at 3:30 p.m., compared with 1,343.6 at the previous trading close, Yonhap reported, meaning the won strengthened. Yonhap put the yield on South Korea’s three-year Treasury bonds up 2.8 basis points to 3.961%, and its five-year government bond yield up 1.7 basis points to 4.134%. Those domestic measures are distinct from the U.S. 10-year yield cited by SBS.

What investors are watching next

Samsung Electronics’ scheduled preliminary third-quarter earnings announcement on Oct. 8 is the next company event identified by both reports. Its figures were not available in their accounts of Wednesday’s trading. For now, the confirmed outcome is a second consecutive KOSPI decline, led in part by technology shares, alongside reported selling by overseas and institutional investors. The role of yields, oil and earnings expectations remains an attributed explanation of the session rather than a measured breakdown of its causes.