Asian Stocks Slide As U.S.-Iran Strikes Send Oil Up 9%

South Korean equities suffered their steepest decline of the latest regional selloff after renewed U.S.-Iran fighting pushed oil prices sharply higher and drove investors out of technology stocks.

The KOSPI closed 8.95% lower at 6,806.93 after falling more than 9% during the session. The Korea Exchange halted trading for 20 minutes when the decline remained above its 8% circuit-breaker threshold for more than one minute.

Foreign investors sold about 1.7 trillion won ($1.13 billion) of KOSPI shares, while institutional investors unloaded another 2.2 trillion won. Retail investors bought close to 3.9 trillion won as losses accelerated across leveraged products and semiconductor holdings.

The selloff followed a new wave of U.S. strikes against Iranian military targets. U.S. Central Command targeted air-defense systems, coastal radar sites, missile and drone capabilities after attacks on commercial shipping through the Strait of Hormuz.

SK Hynix And Samsung Lead Technology Rout

SK Hynix fell 15.37% to 1.845 million won, its largest one-day decline on record. Samsung Electronics lost 10.7%, while SK Square dropped 17.6%.

The reversal hit a market that had become heavily concentrated around artificial intelligence and high-bandwidth memory stocks. SK Hynix and Samsung had driven much of the KOSPI’s advance during the first half of 2026, leaving the index exposed when investors began reducing chip positions.

The record fall in SK Hynix came one trading session after the company’s U.S.-listed shares completed their Nasdaq debut. Its American depositary receipts later fell another 9.3% as the semiconductor selloff reached Wall Street.

China’s benchmark Shanghai Composite closed 1.54% lower at 3,934.74, while losses also spread through Japanese and other regional equity markets.

Oil Surge Pulls Bitcoin Below $63,000

U.S. crude settled 9.4% higher at $78.14, while Brent gained 9.6% to $83.30 as shipping risks returned to the Strait of Hormuz. The waterway carries roughly one-fifth of global oil supply, leaving energy-importing Asian economies exposed to prolonged disruption.