On the 12th, the KOSPI index opened slightly lower, giving up the 5,600 level.
Investor sentiment appeared to weaken after reports overnight that a Thai-flagged cargo ship was attacked by Iran's Islamic Revolutionary Guard Corps in the Strait of Hormuz. Since the outbreak of the Iran war, this is the first time a civilian merchant vessel has actually been struck in the Strait of Hormuz.
However, as U.S. artificial intelligence (AI) software corporations Oracle released results that beat market expectations and assessments emerged that the incident did not bring major changes to the war situation, the index limited its losses and is moving near flat.
As of 9:13 a.m. that day, the KOSPI index was trading at 5,563.02, down 46.93 (0.84%) from the previous trading day. Foreign investors net sold 176.1 billion won, dragging the index lower. Following net sales in the 200 billion won range the previous day, selling continued that day as well.
Individual investors, by contrast, net bought 265.5 billion won, helping to defend against the index's decline. Among institutions, long-term oriented investment trusts and the National Pension Service are net buying 21.5 billion won and 27.8 billion won, respectively, but securities firms—whose funds often reflect individual exchange-traded fund (ETF) flows—are net selling 156 billion won. However, compared with last week, the scale of selling and buying has not expanded significantly.
Among top market-cap stocks, most are lower, while defense stocks are strong again. Hanwha Aerospace is up more than 2%, and Hanwha Systems (1.49%) and LIG Nex1 (1.75%) are also rising.
On a sharp jump in global oil prices, refiners are also strong. S-Oil is surging more than 4%, and GS Holdings (1.53%) is also higher. According to the New York Mercantile Exchange (CL), April West Texas Intermediate (WTI) futures are up more than 7% and trading around $94. This contrasts with the more than 11% plunge at the close on the 10th (local time).
At the same time, the KOSDAQ index was trading at 1,137.13, up 0.3 points (0.03%) from the previous trading day. The index opened slightly lower but turned higher as individual investors moved to net buy 166 billion won. Foreign investors are net selling 133 billion won, and top market-cap stocks are mixed, fluctuating around 1%.
Overnight, New York stocks ended mixed near flat as tensions from the Iran war persisted. On the 11th (local time) at the New York Stock Exchange (NYSE), the Dow Jones Industrial Average fell 289.24 points (0.61%) to close at 47,417.27. The Standard & Poor's (S&P) 500 fell 5.68 points (0.08%) to 6,775.80, while the Nasdaq composite added 19.03 points (0.08%) to finish at 22,716.13.
However, Oracle, which released results that beat market expectations, jumped 9%. Oracle disclosed on the 10th (local time) that revenue for the third quarter of the fiscal year (Dec. 2025–Feb. 2026) rose 22% on-year to $17.19 billion (about 25 trillion won). That exceeds the $16.91 billion forecast compiled by market research firm LSEG.