Institutional Korea Market Close Report: KOSPI and KOSDAQ Advance Amid Sector Divergence

### 1. Identification of Core Common Factors and Money Flow Thesis On September 26, 2026, the South Korean regular market successfully defended key index levels despite external macroeconomic pressures such as the USD/KRW exchange rate at 1,367.4 and the US 10-year Treasury yield at 5.18%. The KOSPI closed up +63.01pt (+0.90%) at 7,080.92pt, and the KOSDAQ advanced +10.10pt (+1.21%) to 844.48pt. Despite institutional and foreign supply frictions, bargain-hunting in large-cap semiconductor and export leaders supported the indices. Screening results indicate that upside breakout leaders are concentrated in machinery and industrial manufacturing (5 stocks, ~50%), steel and industrial metals (1 stock), and finance/securities (1 stock). These companies share fundamental traits of strong export momentum, exchange rate benefits, and earnings quantum leaps driven by surging order backlogs. Recent disclosures and news regarding major shareholders increasing stakes and large-scale supply contracts have solidified market confidence. From a technical perspective, these leading stocks recorded an average 1-month return of +3.2% and broke above their upper resistance lines accompanied by volume spikes averaging 1.4 times their 20-day averages, establishing a textbook trend extension pattern. Conversely, downside vulnerable groups are concentrated in construction and civil infrastructure (2 stocks), machinery laggards (2 stocks), and health supplements/biotechnology (1 stock). They share headwinds of growth valuation discounting under prolonged high interest rates and margin compression from slowing forward demand. They exhibited continuous downtrends within a modest 1-month average return of +0.8%, accompanied by short-term 60-minute downside attempts (D_ATTEMPT) and breaches below 1-month key support lines . ### 2. Quantitative Analysis of Core Leaders Evidencing the Common Thesis LS Eco Energy (229640.KS) demonstrated the clearest supply concentration and price expansion power within the machinery sector, closing up +7.56% at 64,000 KRW with trading volume surging 2.8 times the 20-day average. Over the past month, it has surged +32.2% from the bottom, testing its upper resistance at 67,800 KRW with a support line at 59,600 KRW. SNT Energy (100840.KS) sustained an upward trajectory backed by a 128.2 billion KRW HRSG supply contract disclosure. Closing down -4.68% at 36,700 KRW, it maintains a mid-term uptrend with a +13.3% 1-month return. Upper resistance stands at 40,550 KRW while testing the lower support at 36,500 KRW in a healthy pullback phase. Cenit (037760.KQ) recorded a 1.9x volume surge alongside management stake acquisition disclosures in the steel sector. Closing +0.83% higher at 2,425 KRW, it consolidates energy toward its upper resistance of 2,555 KRW, backed by a solid lower support at 2,160 KRW. ### 3. Downside Laggards and Warning Targets Highlighting Common Risk Factors Dongshin Construction (025950.KQ) reflected demand contraction and high interest rate burdens in the construction sector, closing down -1.10% at 9,880 KRW with a -6.3% 1-month return. With a wide gap from upper resistance at 13,840 KRW, it tests lower support at 8,170 KRW, requiring conservative risk management. Nuon (123840.KQ) showed weakness due to earnings visibility concerns and changes in major shareholders within the biotech sector, closing down -1.30% at 1,750 KRW with volume drying up to 0.3x of its 20-day average. It remains capped below upper resistance at 2,325 KRW, requiring close monitoring of the 1,355 KRW support level. BQ AI (148780.KQ) faced selling pressure amid short-term volatility, closing down -4.21% at 3,755 KRW. A wide band between upper resistance at 6,420 KRW and lower support at 1,850 KRW necessitates strict stop-loss discipline. ### 4. Tactical Response Strategy Based on Thesis Continuity For upside breakout leaders in machinery and exports, maintain a scale-in buying stance supported by quantitative metrics like order backlogs and volume spikes. Avoid chase-buying near resistance lines like LS Eco Energy and focus on pullback entries near lower support levels. For downside laggards and support-threatened groups, apply a principle of reducing positions upon rallies. Construction and lagging small-cap sectors lack clear momentum and suffer from dry trading value, demanding strict stop-loss execution to protect capital.