South Korea’s KOSDAQ index surged nearly 6%, triggering its third buy-side circuit breaker since the start of August. The rally came as concerns about a semiconductor peak eased and risk appetite returned, with foreign and institutional investors concentrating heavy buying on large-cap KOSDAQ stocks.

As of 11:01 a.m. on August 10, the KOSDAQ index stood at 846.10, up 47.29 points, or 5.92%, from the previous session. The index opened 1.11% higher at 807.66 before accelerating sharply around 9:50:48 a.m., triggering the buy-side circuit breaker. The measure was activated after KOSDAQ 150 futures prices rose more than 6% from their reference price while the KOSDAQ 150 index simultaneously gained more than 3% from the previous session’s final level for one minute. Program buy orders were suspended for five minutes as a result.

The KOSDAQ market previously saw buy-side circuit breakers triggered on July 31, as well as August 3 and 4. This means circuit breakers have been activated on three of the six trading days so far in August, reflecting extreme volatility.

Foreign and institutional investors drove the day’s KOSDAQ surge. Foreigners bought a net 170 billion won (approximately $119.8 million), while institutions purchased a net 284 billion won (approximately $200.1 million), lifting the index. Retail investors, by contrast, sold a net 447 billion won (approximately $314.9 million), appearing to take profits. Buying sentiment spread broadly, with more than 75% of all KOSDAQ-listed stocks — 1,390 issues — advancing.

Among individual stocks, market-cap leader Alteogen soared 15%, leading the market. The rally was fueled by a disclosure that BlackRock, the world’s largest asset manager, holds a 5% stake in the company. Jusung Engineering also posted double-digit gains, rising 10.25%, while second- and third-largest stocks EcoPro and EcoPro BM gained between 5% and 6%.

The KOSPI also rebounded after three sessions of declines, though gains were limited. At the same time, the benchmark index was up 41.27 points, or 0.66%, at 6,287.63. The index had surged as high as 6,394.06 in early trading, up 2.16%, but gave back much of those gains as foreign selling intensified.

In the KOSPI market, foreigners sold a net 532 billion won (approximately $374.8 million), while institutions bought a net 350 billion won (approximately $246.6 million), defending against further declines. Retail investors purchased approximately 150 billion won (approximately $105.7 million), joining institutions on the buy side. In the KOSPI 200 futures market, however, foreigners showed a net buying bias of 262 billion won (approximately $184.6 million), contrasting with their activity in the spot market.

The broader market’s upward momentum originated from Wall Street. At the end of last week, the Dow Jones Industrial Average rose 0.28%, the S&P 500 gained 0.62%, and the Nasdaq Composite jumped 1.30%. Notably, the S&P 500 set a new all-time closing high, while the Philadelphia Semiconductor Index surged 2.56%, reviving investor sentiment toward the chip sector.

“Nvidia rose amid broad strength in AI server and networking-related companies, while U.S. optical communications firm Coherent gained on expectations for high-speed optical communication demand from AI data centers,” said Kim Rok-ho, an analyst at Hana Securities.

Buoyed by the momentum, Samsung Electronics and SK hynix rose 0.43% and 1.55%, respectively. Morgan Stanley’s outlook that the memory stock correction has ended and re-entry is attractive boosted not only large-cap semiconductor names but also equipment stocks.

However, a Wall Street Journal report that Apple is testing chips from China’s ChangXin Memory Technologies (CXMT) in products including iPhones and MacBooks stirred some caution. News that Apple is considering using CXMT chips for devices sold in China was seen as a potential threat to South Korea’s memory semiconductor industry.

By sector, medical and precision equipment led gains with a 5.88% advance. The metals sector also surged 5.61%, largely driven by Korea Zinc’s more than 11% jump. U.S. Commerce Secretary Howard Lutnick cited Korea Zinc as a prime example while unveiling critical mineral investment plans, noting the company’s $7.4 billion investment in a Tennessee smelter — a remark that positively influenced investor sentiment.

Hanwha Aerospace gained over 5% on news of a second space center construction project, with space-related stocks broadly rallying in sympathy. Sangsangin Securities extended its winning streak to three consecutive sessions on expectations surrounding its pursuit of an acquisition of Sh Suhyup Bank. On the KOSPI, however, KB Financial Group fell 3.8%, while transportation and warehousing, chemicals (-2.24%), and telecommunications (-2.00%) sectors also remained under pressure.

Across the KOSDAQ market, all sectors either advanced or held steady. General services and non-metallic sectors posted gains in the 10% range, while the global sector (8.61%), technology growth companies (7.67%), and machinery and equipment (7.23%) all showed strength, driving a broad-based market rally.