KOSPI Falls Below 7,000 as Oil Tops $101, Yields Rise

South Korea’s KOSPI fell to 6,961.23 on Thursday, down 1.28%, as rising oil prices and higher US Treasury yields prompted broad selling across the market.

Samsung Electronics slid 1.3%, SK Hynix fell 0.59%, Hyundai Motor lost 1.55% and LG Energy Solution declined 2.83%. Foreign investors were net sellers of 496.4 billion won and institutional investors sold just over 1 trillion won. Retail traders were net buyers on Thursday.

Brent crude traded above $101 a barrel after a fresh escalation in fighting in the Middle East. US crude WTI reached $96.05. South Korea imports most of its oil and gas, and higher fuel prices increase costs for transport, manufacturing and households.

The US 10-year Treasury yield hovered near 4.84%, close to highs last seen in 2023. The US Treasury announced a $6 billion buyback of longer-dated debt; some investors had expected a larger repurchase in the $7 billion-$8 billion range, leaving the announced amount below those expectations, according to Raymond James strategist Tracey Manzi.

Trading was affected by a quadruple-witching expiration in South Korea, when index futures, index options, single-stock futures and single-stock options all expire on the same day. That expiration amplified programme trading and foreign futures flows and contributed to volatility.

Retail investors have been active in recent sessions. Market data show retail investors sold 16.84 trillion won over the five sessions through Wednesday, with institutions, foreign investors and corporate treasury-share purchases absorbing much of that supply. On Thursday, retail traders bought while foreign and institutional players reduced positions.

Pressure on equities was regional. The MSCI Asia-Pacific gauge fell about 0.4%. Japan’s Nikkei 225 dropped 0.6% to 64,759.80 and Australian shares also retreated as higher energy costs weighed on risk appetite.

Investors will monitor US economic data this week, with producer-price figures due on Thursday and consumer-price inflation data scheduled for Friday, which may influence yields and market sentiment.