South Korean stocks extended their rally on Tuesday, December 23, 2025, after Monday's 2.12 percent close at 4,105.93. The KOSPI rose 0.58 percent to 4,195.78 by 11:20 a.m., boosted by sustained US tech gains and President Trump's naval warship plan with Hanwha.
The index opened at 4,125.46, up 0.48 percent in the first 15 minutes. Foreigners and institutions net bought 405 billion won and 409 billion won, respectively, echoing Monday's heavy buying.
US indexes advanced overnight—Dow +0.47 percent, Nasdaq +0.52 percent, S&P 500 +0.64 percent—sustaining AI optimism. Shipbuilders led on Hanwha news: Hanwha Ocean +5.2 to 10.48 percent, HD Hyundai Heavy +1.56 to 2.72 percent, HD Korea Shipbuilding & Offshore +0.72 to 2.03 percent. Hanwha Aerospace +0.68 to 0.9 percent.
Tech followed: Samsung Electronics +0.81 to 1.49 percent, SK hynix +1.29 to 1.72 percent. LG Energy Solution dipped 0.39 to 0.9 percent; Korea Electric Power fell 1.33 to 1.43 percent.
The won weakened to 1,482.7-1,483.4 per dollar, down 2.6-3.3 won.
