Semiconductor stocks soar on Micron results, lifting Kospi near 6,970 and Kosdaq up over 4%

The Kospi closed nearly 2 percent higher Thursday, finishing around the 6,970 level on the back of strong earnings from Micron Technology and robust domestic export data. Samsung Electronics and SK hynix each gained roughly 3 percent, leading the benchmark index higher. The Kosdaq also surged more than 4 percent, breaking above the 890 mark.

According to Korea Exchange, the Kospi rose 133.31 points, or 1.95 percent, to close at 6,971.35. The index opened down 23.55 points, or 0.34 percent, at 6,814.49, but reversed course during trading and extended its gains through the session.

Institutional investors were net buyers of 334.5 billion won ($247 million) on the main board. Retail and foreign investors were net sellers of 1.43 trillion won and 548.5 billion won, respectively.

Semiconductor stocks drove the index's advance. Samsung Electronics closed up 7,500 won, or 2.79 percent, at 276,000 won, while SK hynix gained 57,000 won, or 3.21 percent, to finish at 1.83 million won.

Buying flowed into domestic semiconductor shares after Micron overnight reported earnings and guidance that topped market expectations. Micron's revenue for the fourth quarter of fiscal year 2026 came in at $54.23 billion, exceeding the consensus estimate of $51.07 billion. Its revenue guidance for the next quarter, at $60 billion to $63 billion, also surpassed market forecasts.

Strong domestic export figures further lifted sentiment in the semiconductor sector. South Korea's exports in September surged 83.5 percent year-on-year to $120.94 billion. Semiconductor exports soared 262.8 percent to $60.3 billion.

"The domestic market rallied as it priced in a string of positive catalysts," said Lee Kyung-min, an analyst at Daishin Securities. "Micron's strong earnings and South Korea's September export performance both acted as upward pressure on the semiconductor sector."

Among large-cap stocks, Samsung Electronics preferred shares rose 4.76 percent, while Samsung Electro-Mechanics gained 3.17 percent, Samsung Biologics 2.73 percent, SK Square 1.40 percent, Hyundai Motor 1.16 percent, LG Energy Solution 0.98 percent and Samsung Life Insurance 0.71 percent. KB Financial Group fell 1.66 percent.

The Kosdaq closed up 38.38 points, or 4.48 percent, at 894.29. The index opened down 1.95 points, or 0.23 percent, at 853.96, but turned positive during the session and extended its gains.

On the Kosdaq, institutional and foreign investors were net buyers of 568.3 billion won and 228 billion won, respectively. Retail investors were net sellers of 776.4 billion won.

All 10 of the Kosdaq's largest stocks by market capitalization closed higher. Alteogen rose 4.13 percent, Ecopro 5.58 percent, Jusung Engineering 3.56 percent, Ecopro BM 5.13 percent, Rainbow Robotics 5.02 percent, Wonik IPS 9.13 percent, EO Technics 8.46 percent, Leeno Industrial 10.90 percent, Simtech 6.25 percent and HPSP 8.32 percent.