(LEAD) Seoul shares sink nearly 6 pct on tech rout, rising yields

Seoul shares plummeted nearly 6 percent on Wednesday, heavily influenced by declines in chip manufacturers, as higher oil prices and increasing global bond yields dampened investor confidence. The Korean won strengthened against the U.S. dollar. The KOSPI index fell by 398.66 points, or 5.8 percent, to close at 6,471.17 after briefly dropping to 6,400.81.

Shortly after trading commenced, program trading in KOSPI-listed shares was halted for five minutes due to the bourse operator activating a sell-side sidecar. This occurred when the KOSPI 200 futures index dropped by 5 percent or more within a minute. Earlier in the day, major Wall Street indexes closed lower as negotiations between the U.S. and Iran stalled, causing oil prices to surge.

The 30-year U.S. Treasury yield reached its highest level since 2007 due to worries that higher energy costs could sustain inflation. Trading volume was relatively light, with 302.07 million shares worth 22.94 trillion won ($16.4 billion) exchanged, and outperforming stocks outnumbered underperforming ones by a ratio of 700 to 171.

Foreign investors and institutions sold a combined net of 480.2 billion won, while domestic investors bought 463.6 billion won. Analyst Lee Kyoung-min from Daishin Securities noted that foreign investors and institutions offloaded local semiconductor shares, such as Samsung Electronics and SK hynix, due to growing doubts about their prospects as bond yields rose.

Market leaders Samsung Electronics and SK hynix both saw significant drops, with Samsung Electronics falling 7.82 percent to 247,500 won, and SK hynix declining 9.75 percent to 1.5 million won. SK Square, the parent company of SK hynix, slipped 11.54 percent to 1 million won, while Samsung Electro-Mechanics, an electronics component subsidiary of Samsung Electronics, decreased by 3.68 percent to 1.38 million won.

Hanwha Aerospace increased by 2.71 percent to 1,177,000 won after reporting that its U.S. subsidiary had secured a contract to deliver K9 self-propelled howitzer prototypes to the U.S. Army. At 3:30 p.m., the Korean won was trading at 1,397.7 won per U.S. dollar, up 14.1 won from the previous trading session's close.