South Korean stocks surged Thursday, climbing past the 3,500 mark for the first time, as investors welcomed news of business partnerships between OpenAI and top chipmakers Samsung Electronics and SK hynix. The local currency strengthened against the U.S. dollar.
The benchmark Korea Composite Stock Price Index (KOSPI) added 93.38 points, or 2.7 percent, to close at 3,549.21, surpassing the previous record high of 3,486.19 set on Sept. 23.
Trade volume was heavy at 394.92 million shares worth 18.57 trillion won (US$13.25 billion), with winners outnumbering losers 589 to 291.
Foreigners bought a net 3.14 trillion won worth of shares, while retail and institutional investors sold 3.07 trillion won and 69 billion won worth of shares, respectively.
Investor sentiment was buoyed by the news that chip giants Samsung Electronics and SK hynix signed letters of intent Wednesday to supply memory chips for OpenAI’s data centers.
“Despite macroeconomic and political factors, such as the U.S. government shutdown and stalled tariff talks with the U.S., investors are focusing on artificial intelligence, semiconductors and other leading sectors,” Kiwoom Securities analyst Han Ji-young said.
“Investors often boost cash holdings ahead of long holidays, but this time the overall market trend is unlikely to be affected,” she added.
The South Korean stock and foreign exchange markets will be closed from Friday through next Thursday for the extended Chuseok holiday.
Market bellwether Samsung Electronics surged 3.49 percent to 89,000 won, while chip giant SK hynix spiked 9.86 percent to 395,500 won.
Leading battery maker LG Energy Solution soared 14.82 percent to 399,000 won, and nuclear power plant manufacturer Doosan Enerbility gained 0.31 percent to 64,800 won.
Major bio company Samsung Biologics grew 0.4 percent to 1,009,000 won, and Celltrion went up 0.17 percent to 175,400 won.
Carmakers gathered ground. Top automaker Hyundai Motor increased 2.09 percent to 220,000 won, while its sister affiliate Kia jumped 3.58 percent to 104,200 won.
Shipbuilders finished mixed. Industry leader HD Hyundai Heavy remained unchanged at 528,000 won, while Hanwha Ocean climbed 1 percent to 111,500 won.
But defense giant Hanwha Aerospace edged down 0.18 percent to 1,097,000 won, and top internet company Naver tumbled 0.59 percent to 253,000 won.
The local currency was quoted at 1,400.0 won against the U.S. dollar at 3:30 p.m., up 3.2 won from the previous session.
Bond prices, which move inversely to yields, closed higher. The yield on three-year Treasurys fell 1.5 basis points to 2.581 percent, and the return on the benchmark five-year government bonds shed 1.9 basis points to 2.729 percent.