The South Korean KOSPI index fell 5.8% [1] to approximately 6,471 points [1] amid rising U.S. Treasury yields and foreign sell pressure.

This volatility signals a heightened sensitivity in East Asian markets to U.S. monetary shifts, threatening regional stability and corporate investment.

The market opened with a sharp decline, starting at 6,529 points [1]. During the trading session, the index hit an intraday low of around 6,400 points [1] before closing. This downward trend was driven by a combination of institutional sell-offs and foreign investors exiting positions.

Global macroeconomic pressures played a central role in the crash. The yield on the U.S. 30-year Treasury reached 5.3% annually [1], marking a 19-year high. This spike in yields typically makes U.S. assets more attractive, drawing capital away from emerging markets like South Korea.

Additional pressure came from a U.S. state administrative order regarding data-center construction approvals, which impacted investor sentiment in the tech sector. The resulting instability extended to the foreign exchange market, where the Korean won fell back into the 1,300-won per dollar range [1]. This level has not been seen in approximately 10 months [1].

Despite the broader crash, individual investors attempted to stabilize the market. Retail traders engaged in net buying totaling close to five trillion won [1], though this was not enough to offset the institutional exodus.

Reporting from YTN News highlighted the severity of the opening bell. "The KOSPI started with a sharp decline, opening at 6,529, down 4.96%," said reporter Yoon Tae-in.

Yoon said the plunge was largely due to the impact of surging government bond yields in major economies, specifically the U.S. 30-year Treasury hitting that 5.3% mark.

“The KOSPI index fell 5.8% to approximately 6,471 points.”

The simultaneous drop in the KOSPI and the weakening of the won illustrate a 'double whammy' effect where currency devaluation and equity losses occur together. Because South Korea is heavily dependent on exports and foreign capital, the surge in U.S. Treasury yields creates a vacuum that pulls liquidity out of Seoul. The failure of retail investors' five trillion won intervention to stop the slide suggests that institutional confidence has shifted significantly toward U.S. safe-haven assets.