Seoul, Nov 7 : After choppy trading, South Korean shares ended 1.8 per cent lower on Friday, capping a turbulent week, as big-cap tech shares lost ground amid concerns over an artificial intelligence (AI) bubble, and renewed trade tensions between the United States and China.

The benchmark Korea Composite Stock Price Index (KOSPI) tumbled 72.69 points, or 1.81 percent, to close at 3,953.76, after touching an intraday low of 3,887.32, reports Yonhap news agency.

Trade volume was moderate at 366.7 million shares worth 18.6 trillion won (US$12.8 billion), with losers outnumbering winners 677 to 211.

Foreigners and institutions unloaded local shares worth 472.2 billion won and 228.1 billion won, respectively, while retail investors continued their buying spree, purchasing 695.9 billion won.

This week, the KOSPI suffered severe volatility, reaching a record high of over 4,200 on Monday, but plunging nearly 3 percent on Wednesday.

The KOSPI started off weak, tracking overnight losses on Wall Street sparked by revived fears over the stretched valuation of AI-related shares and data showing a cooling labour market.

The Dow Jones Industrial Average fell 0.84 percent, the tech-heavy Nasdaq composite dipped 1.9 percent, and the S&P 500 went down 1.12 percent.

The latest data from Challenger, Gray & Christmas Inc. revealed that U.S. companies announced 153,074 job cuts last month, marking almost a threefold increase from the same month last year.

In the early afternoon, the KOSPI once tumbled over 3 percent as media reports suggested the White House has decided not to allow Nvidia to sell its latest scaled-down AI chips to China, stoking concerns the trade tensions between the world's two largest economies will once again escalate, according to Seo Sang-young, an analyst at Mirae Asset Securities.

"In addition, China's exports decreased 1.1 percent in October, marking the first on-year drop since March 2024, fueling concerns South Korea's exports may also decrease," Seo noted.

In Seoul, market bellwether Samsung Electronics lost 1.31 percent to 97,900 won, and its chipmaking rival SK hynix dipped 2.19 percent to 580,000 won, dragged down by AI bubble woes.

Leading carmaker Hyundai Motor retreated 1.86 percent to 264,000 won, and its sister Kia dropped 1.7 percent to 110,100 won.

Top battery maker LG Energy Solution pulled back 1.38 percent to 463,500 won, and its smaller rival Samsung SDI plunged 4.97 percent to 306,000 won.

Electric equipment manufacturer HD Hyundai Electric nosedived 6.51 percent to 818,000 won, while state-run Korea Electric Power slid 4.34 percent to 44,100 won. Major power plant builder Doosan Enerbility declined 1.77 percent to 77,900 won.

Defence shares lost big, with Hanwha Aerospace losing 4.85 percent to 932,000 won and LIG Nex1 shooting down 16.53 percent to 401,500 won.

Major shipbuilder Hanwha Ocean was among the few gainers, jumping 3.09 percent to 126,800 won.

Kakao, the operator of the country's dominant mobile messenger, soared 3.46 percent to 62,800 won after delivering stronger-than-expected earnings.

The local currency was quoted at 1,456.9 won against the greenback at 3:30 p.m., sharply down by 9.2 won from the previous session to reach a seven-month low.

It marked the first time since April that the currency slipped below the psychologically crucial 1,450 won threshold, as foreign selling of local stocks added pressure on the currency.

Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys rose 6 basis points to 2.894 percent, and the return on the benchmark five-year government bonds added 5 basis points to 3.043 percent.

/IANS