South Korean Stocks Pivot from Global Leaders to Laggards Amid AI and Energy Headwinds

The South Korean stock market experienced a dramatic reversal in March 2026, transitioning from the world's best performer to its worst within a single quarter. This sharp decline follows a cooling AI boom, which has weighed heavily on major memory chip-makers such as Samsung Electronics and SK Hynix. Market sentiment deteriorated further following a joint military attack by the United States and Israel on Iran on February 28, 2026. While the broader KOSPI index struggled, energy industry stocks bucked the trend, recording significant double-digit gains throughout March. The geopolitical escalation has heightened pressure on the export-heavy Korean economy due to surging energy costs. Analysts note that the market remains highly vulnerable to both global tech cycles and external geopolitical shocks affecting energy supplies.