The Korean stock market experienced a 'Black Thursday' on the 15th, with both the KOSPI and KOSDAQ plummeting more than 7%. Large-cap semiconductor stocks such as Samsung Electronics and SK hynix recorded double-digit declines, and selling pressure also poured into major KOSDAQ sectors including secondary batteries and biotech. Following the U.S. Consumer Price Index (CPI) release, the Producer Price Index (PPI) announced on the night of the 15th also came in above market expectations, drawing attention to the direction of the domestic market on the 16th, ahead of the weekend.

KOSPI Falls 7.57% and KOSDAQ 7.65%; Circuit Breakers Triggered in Both Markets

On the 15th, the KOSPI closed at 5,554.22, down 454.59 points (7.57%) from the previous trading day. The index opened at 5,673.01 and rose as high as 5,751.45 during the session, but losses widened thereafter, sending it down to 5,450.81. Although the market attempted a partial rebound in the late session, it ended the day without recovering the 5,600 level.

The KOSDAQ could not escape the sharp decline either. It closed at 760.82, down 63.06 points (7.65%) from the previous day, and after recording an intraday high of 788.69, mounting selling pressure pushed it down to 745.43. Both markets triggered the first-stage circuit breaker, temporarily halting trading and displaying extreme volatility.

Samsung Electronics Down 10.56% and SK hynix 12.76%; Semiconductor Stocks Post Steep Losses

The semiconductor sector posted the largest decline on the KOSPI. Samsung Electronics finished at 207,500 won, down 10.56%, while SK hynix closed at 1,238,000 won, down 12.76%. Samsung Electronics preferred shares (-10.31%) and SK Square (-11.97%) also fell together.

Samsung Electro-Mechanics fell 18.34% to 1,122,000 won, and Hyundai Motor and LG Energy Solution declined 7.66% and 6.87%, respectively. In contrast, Samsung Biologices rose 4.99% to close at 1,241,000 won, while KB Financial (0.44%) and Shinhan Financial Group (1.16%) also climbed, performing relatively well amid the market rout.

KOSDAQ Also Hit by 'Indiscriminate Selling'; Wonik IPS and Jusung Engineering Plunge Around 18%

On the KOSDAQ, semiconductor equipment stocks took a heavy blow. Wonik IPS closed down 18.35% at 99,200 won, while Jusung Engineering fell 18.05% to 197,100 won. Eotechnics also dropped 11.53%.

Secondary battery-related stocks could not avoid weakness either. EcoPro and EcoPro BM fell 10.34% and 11.85%, respectively, while L&F also declined 7.35%. In the biotech sector, Alteogen (-12.19%), RigaChemBio (-13.55%), Samchundang Pharm (-14.61%), and HLB (-4.64%) all closed lower. All of the top 10 KOSDAQ stocks by market capitalization declined, showing weakness not limited to any specific sector.

U.S. September CPI Up 3.7% and PPI Up 6.3%; Price Pressures Persist

The market's focus is on U.S. inflation indicators. The U.S. September CPI, released on the 14th Korean time, rose 3.7% year over year, while core CPI, excluding food and energy, increased 2.6%. After the release of these figures, U.S. stock markets in New York weakened, followed by a plunge in the domestic market, elevating inflation uncertainty to a major variable across global financial markets.

The U.S. September PPI, released on the 15th Korean time, also recorded a higher-than-expected increase. According to the U.S. Bureau of Labor Statistics, September PPI rose 6.3% year over year, and core PPI also increased 5.0% year over year, demonstrating that price pressures remain strong. With both CPI and PPI showing elevated levels, attention is expected to focus on how the market interprets the future course of U.S. Federal Reserve (Fed) monetary policy.

Key Points for the 16th: Rebound vs. Caution; Whether KOSPI Holds 5,500 and KOSDAQ 750

As the domestic market will confirm the U.S. PPI results after the close on the 15th, how these figures will be reflected in trading on the 16th has emerged as a new focal point. On Friday the 16th, ahead of the weekend, attention is on whether rebound buying will flow in following the plunge or whether cautious sentiment will persist due to external uncertainty. Whether the KOSPI holds the 5,500 level and the KOSDAQ holds the 750 level is also a point of interest.

The movement of large-cap semiconductor stocks such as Samsung Electronics and SK hynix is cited as one of the key variables for gauging the index's direction. In addition, with the further reaction of U.S. markets, foreign investor flows, and the won-dollar exchange rate movement all intertwined, the possibility of expanded intraday volatility cannot be ruled out. With both indices pushed down more than 7% in a single day, all eyes are on whether the fallout from U.S. inflation data will lead to further declines or serve as an opportunity to recover part of the losses, as the direction of the domestic market on the 16th remains in focus.

[※ This article is intended to convey market trends and is not intended to recommend investment in any specific stocks.]