The South Korean won posted its sharpest gain against the U.S. dollar in three years after a strong verbal intervention from foreign exchange(FX) authorities, while Seoul shares closed lower on Wednesday as investors locked in profits following a recent rally in tech and shipbuilding. 

The South Korean won strengthened against the U.S. dollar by 33‑point‑eight won, trading at one‑thousand‑449‑point‑eight won as of the 3:30 p.m. spot trading, marking its biggest single‑day rise in more than three years.

The sharp rebound followed comments from FX authorities that an excessively weak won was “not desirable.” The remarks came as the local currency has hovered near its weakest level in 16 years despite a series of stabilization measures.

Meanwhile, the benchmark Korea Composite Stock Price Index edged down eight‑point‑seven points, or zero‑point‑21 percent, to close at four‑thousand‑108‑point‑62.

Trading volume was moderate at 351‑point‑five million shares worth eleven‑point‑95 trillion won, about eight‑point‑two billion U.S. dollars, with decliners outnumbering gainers 481 to 378.

Samsung Electronics slipped zero‑point‑36 percent to 111‑thousand‑100 won, while SK hynix rose zero‑point‑88 percent to 588‑thousand won.

Automobile shares advanced, with Hyundai Motor and its auto parts subsidiary Hyundai Mobis gaining zero‑point‑seven percent and zero‑point‑55 percent, respectively.

LG Energy Solution added zero‑point‑64 percent, and artificial intelligence investment firm SK Square climbed one‑point‑nine percent.

Doosan Group jumped nearly four percent on expectations over its planned acquisition of SK Siltron, while POSCO Group surged three‑point‑29 percent.

Major shipbuilders declined, with Hanwha Ocean down three‑point‑57 percent, HD Korea Shipbuilding shedding three‑point‑seven percent, and HD Hyundai slipping two‑point‑63 percent.

Young Poong plunged 9.32 percent after a court rejected its bid to block Korea Zinc’s planned third‑party capital increase in connection with the company’s planned investment in a critical‑metals refinery in the U.S.

The tech‑heavy KOSDAQ lost four‑point‑36 points, or zero‑point‑47 percent, to close at 915‑point‑two.