South Korea’s benchmark stock index reached a historic milestone on Friday. Then, within hours, it gave most of it back.
The Korea Composite Stock Price Index (KOSPI) briefly touched an intraday record high of 8,046.78 before reversing sharply to close at 7,493.18, a drop of 6.1% for the session. The sell-off triggered a regulatory circuit breaker, as South Korea’s Korea Exchange (KRX) halted program trading for five minutes after KOSPI 200 futures fell more than 5% in under a minute. Furthermore, the KOSPI remains up roughly 80% year-to-date, so Friday’s move reflects a rapid consolidation after one of the most aggressive equity rallies in recent global market history.
A Rally Built on Chips
To understand Friday’s reversal, investors first need to understand what drove the KOSPI to 8,000 in the first place.
The index has surged on the back of South Korea’s two dominant chipmakers. Samsung Electronics Co., Ltd. (OTC:SSNLF) (KRX: 005930) and SK hynix Inc. (KRX: 000660) together account for approximately 42.2% of the entire KOSPI weighting, according to Manulife Investment Management. Both companies produce high-bandwidth memory (HBM) chips, which sit at the center of the global AI infrastructure buildout. As a result, Wall Street capital has poured into Korean equities at an accelerating pace in 2026. That concentration, however, cuts both ways.
When these two names sell off, the broader index has little to stand on.
What Triggered the Reversal
Several catalysts converged on Friday to ignite the profit-taking.
First, Samsung’s labor union announced an 18-day strike beginning May 21, involving more than 45,000 workers at its chip division. The company had proposed resuming wage negotiations without preconditions, but the union declined, stating it would only return to talks after June 7. NH Investment & Securities analyst Na Jeong-hwan noted that the labor dispute now …
This post was originally published here
