South Korean stocks surged more than 2% on Friday to close at an all-time high, led by strong gains in large-cap semiconductor shares. The benchmark KOSPI index rose 2.27% to 4,309.63, crossing the 4,300 level for the first time. The local currency weakened slightly against the U.S. dollar.
The benchmark Korea Composite Stock Price Index (KOSPI) rose 95.46 points, or 2.27%, to close at 4,309.63, marking an all-time high and surpassing the 4,300 level for the first time. The previous record stood at 4,221.87 on November 3, fueled by optimism over artificial intelligence (AI)-driven growth.
Trading volume was moderate at 400.33 million shares worth 17.27 trillion won ($11.97 billion), with decliners outnumbering advancers 522 to 371. The index opened higher and extended gains as offshore investors turned net buyers. Foreigners purchased a net 644.68 billion won of shares, while individuals and institutions offloaded 454.43 billion won and 233.37 billion won, respectively.
Analysts attributed the surge to robust exports offsetting recent U.S. equity weakness, alongside bets on sustained AI momentum. South Korea's 2025 exports hit a record $709.7 billion, exceeding $700 billion for the first time, driven by AI and semiconductors, according to government data.
"The KOSPI is expected to trade in a neutral-to-positive tone, supported by a virtuous cycle of global growth, sales and earnings, along with the government's full-scale efforts to stimulate the economy and the stock market," said Kim Yong-gu, an analyst at Yuanta Securities.
U.S. shares fell on the last trading day of 2025, with the Dow Jones Industrial Average down 0.63% and the Nasdaq composite sliding 0.76%. Large-cap tech stocks spearheaded the rally: Samsung Electronics soared 7.17% to a record 128,500 won, and SK hynix jumped 3.99% to 677,000 won, also a high. In contrast, LG Energy Solution dipped 2.04% to 361,000 won, and LG Chem fell 3.15% to 322,500 won.
Celltrion spiked 11.88% to 202,500 won on expectations of record quarterly earnings and its completion of acquiring a U.S. biopharmaceutical plant from Eli Lilly. Automakers, shipbuilders, and defense firms showed mixed results, while the won traded at 1,441.8 per dollar at 3:30 p.m., down 2.8 won from the prior session.
