KOSPI closes lower after first-ever breach of 3,900…'Sacheonpi' within sight

Large simultaneous net selling by foreigners and institutions

Increased uncertainty in Korea–U.S. trade talks

Exchange rate surpasses 1,440 won for first time in six months

The KOSPI index briefly topped 3,900 intraday on the 23rd but retreated and closed around the 3,840 level. The result came as large sell orders from foreign and institutional investors poured in amid growing uncertainty over Korea–U.S. tariff negotiations. The won–dollar exchange rate exceeded 1,440 won intraday, marking a six‑month high.

On the day, the KOSPI closed at 3,845.56, down 38.12 points (0.98%) from the previous session. After opening down 1.23%, the KOSPI turned up intraday and surpassed 3,900 for the first time, reaching as high as 3,902.21. However, it reversed into a decline in the afternoon as institutions switched to net selling, widening the losses.

In the stock market, foreigners and institutions sold 409 billion won and 399.9 billion won worth, respectively. Institutions, which had been buying early in the session, turned to selling in the afternoon. Individual investors bought 750.1 billion won, but it was insufficient to cushion the index's decline.

Market watchers attributed this to increased uncertainty over Korea–U.S. tariff negotiations amid U.S.–China trade tensions. News circulated that, to secure a Korea–U.S. tariff deal, a plan is being discussed for Korea to invest $25 billion per year for eight years — $200 billion in total (about 286 trillion won).

Earlier, Lee Chang‑yong, governor of the Bank of Korea, said at the National Assembly's Strategy and Finance Committee hearing on the 20th, regarding the U.S. investment fund, "the amount that can be raised within a year without shocking the foreign exchange market is $15–20 billion." The recently discussed $25 billion exceeds that level.

As a result, the won–dollar exchange rate also surged. In the Seoul foreign exchange market, the won–dollar rate closed the week at 1,439.6 won, up 8.6 won from the previous session. It spiked as high as 1,441.5 won intraday, marking the highest intraday level in about six months since April 29 (1,441.5 won).

On news that U.S. electric vehicle maker Tesla's net profit plunged, secondary battery stocks such as L&F (-2.41%), Samsung SDI (-1.71%), and LG Energy Solution (-1.54%) closed weak. On the KOSDAQ, EcoPro (-6.75%) and EcoPro BM (-3.51%) plunged. On the other hand, power equipment stocks such as LS Electric (14.87%), HD Hyundai Electric (8.75%), and Hyosung Heavy Industries (7.55%) surged on expectations of a sharp rise in demand.

Among other top market-cap KOSPI stocks, Naver (-5.09%), Hyundai Motor (-3.45%), Doosan Enerbility (-3.42%), Celltrion (-3.2%), Kia (-2.62%), Samsung Electronics (-2.13%), Samsung Biologics (-0.94%), KB Financial (-0.86%), HD Hyundai Heavy Industries (-0.69%), and SK hynix (-0.62%) fell, while Hanwha Aerospace (4.17%) and Hanwha Ocean (1.89%) rose.

The KOSDAQ closed at 872.03, down 7.12 points (0.81%) from the previous session. After opening down 0.57%, the KOSDAQ's decline widened intraday to as much as 1.18%. On the KOSDAQ as well, foreigners and institutions sold 123.3 billion won and 13.6 billion won, respectively, while only individual investors bought 170.2 billion won.

Among top market-cap KOSDAQ stocks, Samchundang Pharmaceutical (-2.67%), Rainbow Robotics (-1.92%), Peptron (-1.91%), ABL Bio (-1.51%), and RIGAKEM Bio (-1.47%) fell. HLB (0.34%), Alteogen (0.33%), and Pharmaresearch (0.18%) rose slightly.

Ko Jeong-sam, Hankyung.com reporter jsk@hankyung.com