Kospi falls for 4th straight session, retreating to 6,600s despite aftermarket debut

The Kospi ended lower Tuesday after a volatile session, closing in the 6,620s as high oil prices and rising interest rates weighed on investor sentiment — even as the Korea Exchange launched its aftermarket for the first time Monday, opening the door to after-work stock trading.

The Kospi closed at 6,627.26, down 0.85 percent from the previous session, according to Korea Exchange. It was the fourth consecutive session of losses since Thursday.

The index opened down 0.38 percent at 6,659.25, fluctuated near the flat line, then turned lower. At one point during the session it slid as far as 6,582.2, a decline of 1.53 percent.

Samsung Electronics, the largest stock by market cap, closed at 248,500 won ($185), down 0.20 percent. The stock opened at 248,000 won, briefly surged as much as 1.41 percent to 252,000 won in early trading, then reversed course in the afternoon.

SK hynix, the second-largest by market cap, closed down 0.41 percent at 1.69 million won. It had risen as much as 2.73 percent to 1.729 million won at its intraday high, but like Samsung Electronics quickly gave back its gains in the afternoon.

Overnight losses across all three major Wall Street indexes weighed on domestic investor sentiment Tuesday.

The Dow Jones Industrial Average fell 0.29 percent and the S&P 500 dropped 0.48 percent, while the NASDAQ Composite declined 0.56 percent.

The moves came after Saudi Arabia shut down its key East-West Pipeline, stoking fears of a supply disruption and sending crude oil prices sharply higher.

The yield on the 10-year US Treasury note — a global benchmark — also surged past the psychologically significant 5 percent threshold ahead of the Federal Reserve's benchmark interest rate decision, marking the first time it has crossed that level since October 2023.

Concerns about a slowdown in AI spending added further pressure on technology stocks.

On the Kospi market Tuesday, foreign investors and institutions net sold 1.57 trillion won ($1.17 billion) and 904.9 billion won, respectively, while retail investors net bought 833 billion won. Foreign investors have been net sellers on the Kospi for five consecutive sessions since Wednesday.

Other corporations — which have emerged as a major market force recently on the back of large-scale share buybacks by Samsung Electronics and SK hynix — net bought 1.64 trillion won.

The Kosdaq, meanwhile, closed up 0.70 percent at 812.41, snapping a three-session losing streak to rebound for the first time since Thursday. Top-cap stocks Alteogen (up 0.19 percent), Ecopro (up 3.07 percent) and Ecopro BM (up 2.89 percent) all finished higher. Retail investors net sold 140.5 billion won, while foreign investors and institutions net bought 23.8 billion won and 111.4 billion won, respectively.

Korea Exchange launched its aftermarket for the first time Monday, running from 4 p.m. to 8 p.m. Trading value on the inaugural session reached 1.8 trillion won, with volume of 72.24 million shares — equivalent to 6.6 percent of the exchange's total trading value of 27.6 trillion won that day.

Price swings were sharp, however: the static and dynamic volatility interruption mechanism was triggered 1,637 times — roughly four times the 400 activations recorded during regular trading hours from 9 a.m. to 3:30 p.m.

With the number of tradable stocks significantly expanded but capital inflows relatively thin, bid-ask spreads widened for small- and mid-cap stocks, and some investors voiced concern about the elevated volatility.

Technical glitches at several brokerages before the aftermarket opened caused inconvenience for investors, though the issues have since been resolved.

At Mirae Asset Securities, queries for Nextrade pre-market trading history were delayed on both its home trading system (HTS) and MTS. Samsung Securities also experienced failures to reflect cancellation and correction orders, as well as errors in deposit balances.

"In the morning, buying by retail investors and other corporations helped support the index, but macro conditions deteriorated further and buying pressure weakened," said Lee Kyung-min, an analyst at Daishin Securities. "There were no new negative catalysts, but further rises in interest rates and oil prices eroded the appetite of bargain hunters."