South Korean shares opened more than 3 percent lower on Wednesday, November 5, 2025, tracking an overnight slump on Wall Street driven by concerns over lofty stock valuations and an AI bubble. The benchmark KOSPI fell 135.79 points, or 3.29 percent, to 3,985.59 in the first 15 minutes of trading, retreating below the 4,000 mark. This followed a strong run, including breaching 4,200 just days earlier.
South Korean shares opened sharply lower on November 5, 2025, amid an overnight slump in US tech stocks fueled by worries over high valuations and an artificial intelligence bubble. The Korea Composite Stock Price Index (KOSPI) dropped 135.79 points, or 3.29 percent, to 3,985.59 in the first 15 minutes of trading, falling back below the 4,000 level just over a week after first surpassing it. This came after the index closed at 4,121.74 on November 4, snapping a four-day winning streak.
In the US, major indexes closed lower overnight: the Dow Jones Industrial Average fell 0.53 percent, the Nasdaq Composite shed 2.04 percent, and the S&P 500 declined 1.17 percent. Blue-chip tech firms like Nvidia and Palantir lost ground due to AI bubble concerns and comments from Wall Street executives suggesting a market pullback.
In Seoul, most large-cap stocks weakened at the open. Market bellwether Samsung Electronics sank 4.29 percent, while chip rival SK hynix slid 4.78 percent. Leading carmaker Hyundai Motor pulled back 3.26 percent, and defense firm Hanwha Aerospace contracted 3.96 percent. Power plant builder Doosan Enerbility plunged 6.82 percent, and electric equipment provider Hyundai Electric fell 5.23 percent. Shipbuilders also declined, with HD Hyundai Heavy down 3.7 percent, Hanwha Ocean diving 6 percent, and HD Korea Shipbuilding dropping 2.73 percent.
The sell-off followed profit-taking after a recent bull run driven by Asia-Pacific Economic Cooperation (APEC) summit expectations. On November 4, foreigners and institutions net sold 2.2 trillion won and 498.5 billion won worth of shares, respectively, while retail investors net bought 2.7 trillion won amid heavy trading volume of 421.1 million shares valued at 20.7 trillion won. The Korean won traded at 1,445.1 against the US dollar as of 9:15 a.m., down 7.2 won from the prior session.
Daishin Securities analyst Lee Kyoung-min noted, "The KOSPI is now taking a breather after the recent surges driven by expectations surrounding the APEC gathering last week," adding that leaders like Samsung Electronics and SK hynix, along with tariff deal beneficiaries such as automakers and shipbuilders, lost ground.