South Korea stocks crashed 18% in two days. Could it happen here?

In this article EWY Follow your favorite stocks CREATE FREE ACCOUNT A man walks past in front of an electronic screen showing South Korea's benchmark stock index at the Korea Exchange in Seoul on March 3, 2026. Jung Yeon-je | Afp | Getty Images South Korean stocks quickly fell from grace following the U.S. and Israeli strikes on Iran. But Wall Street doesn't see that as a harbinger for anything that's to come in the U.S. The benchmark Kospi Index tumbled more than 12% Wednesday — its worst-ever single day of trading. Korean stocks have plungedmore than 18% so far this week, on track for their biggest weekly loss since 2008. South Korea's stock market was dark on Monday for a national holiday. But a sharp selloff came Tuesday when markets reopened Tuesday in the wake of the Mideast conflict. Korea imports nearly all its fossil fuels, including oil and natural gas, all of it brought in by tanker. About 70% of Korea's oil imports and up to 30% of liquified natural gas comes from the Middle East, according to the U.S. Energy Information Agency . The KOSPI Index, 5-day chart Both the U.S. and Korean markets have been described as concentrated in a handful of stocks. But U.S. investors are quick to point out that Korea's concentration is far greater than even the U.S. What's more, U.S. indexes recently hadn't seen dramatic gains as had their international counterparts. "It's all about perspective," said Jay Woods, chief market strategist at Freedom Capital Markets. Levels of concentration More than one-third of the Korean index is made up of only Samsung Electronics and SK Hynix , Larry Tentarelli of the Blue Chip Trend Report noted. By comparison, the two largest stocks in the S&P 500 — Nvidia and Apple — account for 14% of the index, he said. Samsung Electronics has soared 216% in the past 12 months. SK Hynix, a semiconductor maker, is up 356% over the past year, even including its latest decline, leaving them both "extremely extended," Tentarelli said. If Nvidia and Ap...