Foreigners sold more than 1 trillion won worth of KOSPI spot shares for a sixth straight session, taking cumulative net selling this week past 10.1 trillion won. It was the first such case in the history of South Korea's stock market.

The Korea Exchange said on March 26 that foreigners posted net selling of about 3.5 trillion won on the KOSPI. It said Middle East instability and worries over the semiconductor cycle combined to drive the foreign outflow.

President Trump said he wanted to wrap up the Iran war within the next few weeks, but he approved the deployment of about 3,000 troops from the 82nd Airborne Division to the Middle East. The gap between his remarks and military action heightened market wariness.

A five-day deadline on the U.S. decision to delay strikes on Iran’s strategic facilities is nearing, also strengthening risk-off sentiment. Iran is reported to have rejected a negotiating proposal and counteroffered with war reparations and sanctions relief. International oil prices are also surging as markets reflect the uncertainty.

Google unveiled TurboQuant, an algorithm that can cut AI memory consumption by at least six times, spreading worries about the memory sector outlook.

The pattern resembled the DeepSeek episode earlier, providing a pretext for profit-taking and hitting heavyweight semiconductor stocks. Samsung Electronics fell 4.71 percent, SK Hynix dropped 6.23 percent and Hanmi Semiconductor slid 7.3 percent. Foreign ownership of Samsung Electronics by market capitalisation reached near a historic low.