[Edaily Reporter Kim Hyung-il ] The KOSPI rose for the fourth consecutive trading day, regaining the 6,800 level, driven by strong performance from major semiconductor stocks such as SamsungElectronics(005930)and SK hynix(000660). Buying interest centered on semiconductor stocks as concerns over interest rate hikes eased after the U.S. July Consumer Price Index (CPI) came in line with market expectations, and as AI infrastructure-related companies such as CoreWeave and Supermicro Computer continued to report strong earnings.

According to MP Doctor on the 13th, the KOSPI closed at 6,813.34, up 234.30 points (3.56%) from the previous trading day. The index opened at 6,773.92, up 2.96%, and extended its gains, approaching the 6,900 mark during the session. However, it gave up some of those gains in the afternoon and closed around the 6,800 level.

In particular, large-cap semiconductor stocks led the index higher. SamsungElectronics closed at 268,000 won, up 4.89% from the previous trading day, regaining the 260,000-won mark for the first time in nine trading days since the 31st of last month. SK hynix also closed at 1,593,000 won, up 5.92%, maintaining the 1.5 million won level for the second consecutive day and coming within striking distance of the 1.6 million won mark.

The rally spread to stocks with the highest market capitalizations. SamsungElectroMechanics(009150)surged 12.58% as expectations for rising multilayer ceramic capacitor (MLCC) prices and supply pressures came into focus, while SKSQUARE(402340)also rose 9.08%. Large-cap stocks such as HANWHA AEROSPACE(012450)and SAMSUNG SDI CO.,LTD.(006400) also showed strength, supporting the index’s rise. By sector, buying momentum centered on large-cap stocks—particularly in semiconductors and electrical/electronics—was prominent.

Expectations for continued investment in AI infrastructure in the U.S. stock market also provided a boost to domestic semiconductor stocks. On the 12th (local time), CoreWeave and Supermicro Computer each surged by over 19% on the New York Stock Exchange following strong earnings reports. Navius also soared 34.1% after announcing strong earnings and a major cloud contract. Micron and SanDisk also rose 4.9% and 5.8%, respectively, pushing the Philadelphia Semiconductor Index up by around 2%.

Growing expectations that AI demand is expanding beyond graphics processing units (GPUs) to encompass the entire infrastructure—including memory, servers, and power—also had a positive impact on the domestic stock market. As concerns over AI demand peaking and Big Tech’s reduction in capital expenditures (CAPEX) have eased, expectations are rising that a rebound led by semiconductor stocks could continue.

The upward trend also spread to semiconductor materials, parts, and equipment companies. WONIK IPS Co.,Ltd.(240810)rose by over 7%, and semiconductor equipment stocks such as JUSUNG ENGINEERING Co.,Ltd.(036930) continued their strong performance. Power equipment stocks like LS ELECTRIC(010120) also rose, spreading optimism across the entire AI value chain.

U.S. inflation data also supported the preference for risk assets. The U.S. Consumer Price Index (CPI) for July rose 3.4% year-over-year, in line with market expectations, while the core CPI came in at 2.5%, slowing from 2.6% in June. Following the CPI release, the market increasingly anticipated that the Federal Reserve (Fed) would keep its benchmark interest rate unchanged in September.

However, the day’s index gains did not spread across the entire market. While large-cap stocks on the KOSPI rose 3.82%, mid-cap stocks gained only 0.96%, and small-cap stocks fell 0.49%. In fact, there were 333 gainers on the KOSPI, fewer than the 533 decliners. This indicates a strong concentration of gains among large-cap stocks, particularly in the semiconductor sector.

In terms of supply and demand, foreign investors and institutions supported the KOSPI’s rise. Foreign investors made net purchases of 2.1065 trillion won, while institutions made net purchases of 681.7 billion won; in contrast, retail investors made net sales of 2.7356 trillion won. With the scale of foreign net sales in the domestic stock market having recently decreased significantly, analysts suggest that improved earnings in the semiconductor sector and perceptions of oversold conditions are helping to improve the supply-demand environment.

The KOSDAQ’s gains were relatively limited. The KOSDAQ closed at 861.37, up 2.46 points (0.29%) from the previous trading day. There were 634 gainers and 1,009 losers, with the latter outnumbering the former. Retail investors made net purchases of 257 billion won, while foreign and institutional investors made net sales of 136.3 billion won and 115.7 billion won, respectively.

On the KOSDAQ, semiconductor materials, parts, and equipment stocks—such as JUSUNG ENGINEERING Co.,Ltd.—continued their strong performance, while buying interest also flowed into secondary battery stocks like ECOPRO CO., LTD(086520) and robotics stocks like ROBOTIS(108490). In contrast, K-Beauty stocks such as Hugel, Inc.(145020)and SILICON 2 Co.,Ltd.(257720) showed weakness as profit-taking selling emerged.

Lim Jeong-eun, an analyst at KB Securities, noted, “Following CoreWeave and others the previous day, Navius also surged after reporting strong earnings, driving the rally in AI semiconductor stocks.” This indicates that strong earnings from U.S. AI infrastructure companies have improved investor sentiment toward AI semiconductors, and this positive sentiment has translated into a rally in semiconductor stocks on the domestic market as well.