South Korea’s benchmark KOSPI index has been on an absolute tear in 2026, surging over 90% year-to-date at its peak. The culprit, if you can call it that, is an insatiable global appetite for AI hardware, specifically the high-bandwidth memory (HBM) chips that power everything from large language models to autonomous systems.

Two names dominate the story: Samsung Electronics and SK Hynix. Together, they’ve accounted for approximately 72% of the KOSPI’s total gains.

The numbers behind the surge

SK Hynix has been the standout performer, with its shares rocketing approximately 263% year-to-date by June 2026. Samsung Electronics wasn’t far behind in absolute terms, posting gains of roughly 191% over the same period.

The KOSPI hit all-time highs on May 11, 2026, propelled by a combination of retail buying enthusiasm and favorable pricing dynamics in the AI chip market. Goldman Sachs analysts have identified what they’re calling a “supercycle” in memory chips, where AI demand is simply outstripping available supply.

South Korean retail investors, colloquially known as “ants” for their collective swarming behavior, played a significant role in amplifying the rally. These individual traders piled into semiconductor stocks, resulting in an extraordinary concentration of performance within the index, where a handful of stocks effectively determined the direction of the entire benchmark.

The correction nobody wanted but everyone expected

In early June 2026, the rally hit a wall. Profit-taking and a rotation away from AI-related stocks triggered severe market corrections that erased hundreds of billions in market capitalization.

What this means for investors

One notable absence from this entire episode: crypto. Despite a market environment where billions of dollars were sloshing around in search of AI exposure, there was essentially no crossover into digital assets. Institutional and retail capital in South Korea appears firmly oriented toward traditional equity markets for AI plays, at least for now. Separate reporting has indicated that South Korea is developing AI tools to track cryptocurrency trading gains ahead of anticipated tax implementation, which suggests regulators are thinking about digital assets even if equity investors aren’t.