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Kospi surpasses 8,400 points for first time, triggers buy-side sidecar

Published: 27 May. 2026, 10:02 Updated: 27 May. 2026, 10:14

A screen in Hana Bank's trading room in central Seoul shows the Kospi opening on May 27. [YONHAP]

The benchmark Kospi crossed the 8,400 mark for the first time on Wednesday, rising nearly 5 percent in early trading on the back of strong foreign and institutional buying.

As of 9:20 a.m., the index was up 336.49 points, or 4.18 percent, at 8,384. It opened sharply higher, gaining 2.42 percent to 8,242.12, before extending its gains rapidly as buying momentum built, setting a new all-time intraday high.

As stocks extended gains, a buy-side trading order, also known as a sidecar in Korea, was activated, and Kospi futures were suspended for five minutes at 9:06 a.m., according to the Korea Exchange.

The rally was triggered by Wall Street, where UBS more than tripled its price target on U.S. chipmaker Micron Technology — from $535 to $1,625 — citing the company's transformation from a cyclical commodity producer into a structurally high-margin business, driven by long-term supply agreements. UBS's call ignited a semiconductor supercycle narrative that swept through global markets.

Micron shares surged 19.29 percent overnight to close at $895.88, crossing a $1 trillion market capitalization for the first time in its history. The Philadelphia Semiconductor Index also jumped 5.5 percent to a record high.

The S&P 500 gained 0.61 percent, and the Nasdaq composite rose 1.19 percent.

Adding further fuel to the rally in Seoul, single-stock leveraged exchange-traded funds, or ETFs, tracking Samsung Electronics and SK hynix began trading for the first time on Wednesday. With more than 200,000 investors having completed the mandatory financial education required to trade the products, massive demand flooded into the long-leveraged funds, amplifying gains across the board.

Kospi on the previous day had pulled off a new record high over the 8,000-point level. It was the first time that the Kospi had closed over the 8,000-point level, having only topped the 7,000-point threshold on May 6.

Korea Exchange Chairman Jeong Eun-bo, center, celebrates the Kospi closing above 8,000 points in a ceremony held at the bourse operator's office in western Seoul on May 26. The Kospi on the day rose 2.55 percent to close at a record 8,047.51. [YONHAP]

Samsung Electronics jumped 7.02 percent, and SK hynix spiked 9.99 percent.

Hanmi Semiconductor, a chip manufacturing equipment company, added 1.98 percent, and AI investment firm SK Square surged 12.02 percent.

Carmaker Hyundai Motor, however, fell 0.73 percent, and leading battery maker LG Energy Solution dropped 0.75 percent.

The Kosdaq fell 27.51 points, or 2.35 percent, to 1,145.01.

The won weakened by 1.7 won from the previous session, trading at 1,506 won against the dollar at 9:15 a.m.

BY JEONG JAE-HONG, JANG SEO-YUN, YONHAP [[email protected]]