한국 증시 Emergency Briefing: 2026-05-11
On May 11, the KOSPI soared over 4% during intraday trading, holding steady in the 7,800 range as semiconductor giants led the rally, even triggering a buy-side sidecar. Meanwhile, the KOSDAQ slipped, deepening the "K-shaped" divergence, while a tug-of-war between foreign and individual investors continues.
Korean Market Emergency Briefing — 2026-05-11
Market Snapshot
- KOSPI: Around the 7,880 level (up over 4% from the previous day, intraday basis)
- KOSDAQ: 1,204.13 (down 3.59p from the previous day, as of afternoon)
- KRW/USD Exchange Rate: Opened at 1,466.0 KRW (down 5.7 KRW from the previous trading day)
- Market Sentiment: A massive rally led by large-cap semiconductors triggered a KOSPI buy-side sidecar; KOSDAQ fell, deepening K-shaped polarization; intense buying from individuals and institutions vs. persistent selling by foreigners.

Trading Trends (KOSPI)
- Foreigners: Continued net selling — ongoing large-scale sell-offs this month, following record net buying of the "semiconductor duo" (Samsung Electronics and SK Hynix), now facing profit-taking pressure.
- Institutions: Shifted to net buying — absorbing selling pressure from foreigners alongside individual investors.
- Individuals: Large-scale net buying — absorbing 8 trillion KRW worth of foreign sell-offs in a tight tug-of-war.
Top 5 Key News
KOSPI surges 4% intraday; buy-side sidecar triggered
- What happened?: On May 11, the KOSPI jumped over 4% intraday on the back of a semiconductor-led rally, surpassing the 7,800 mark. The rapid gain triggered a KOSPI buy-side sidecar.
- Market Impact: Semiconductor giants like Samsung Electronics and SK Hynix drove the gains, while the KOSDAQ dipped, worsening the K-shaped market divergence.
Cosmo Robotics hits "quadruple" on KOSDAQ; 12 stocks hit price limit
- What happened?: Cosmo Robotics, newly listed on the KOSDAQ, made headlines by reaching a "quadruple" (4x the IPO price) return. Due to speculative buying in semiconductor value chains, power equipment, and materials, 4 stocks on the KOSPI and 8 on the KOSDAQ hit the daily price limit.
- Market Impact: Speculative buying spreading to semiconductor value chains and the power equipment sector.

Trading volume surges 65%; K-shaped rally intensifies due to semiconductor concentration
- What happened?: While KOSPI trading volume jumped 65% from last month, the gains were concentrated in just four stocks: Samsung Electronics, SK Hynix, Samsung Electronics Pref, and SK Square. Their combined share of KOSPI trading volume rose from 34.6% to 43.9% this month.
- Market Impact: KOSDAQ and small-caps feeling the chill; polarization within the KOSPI between semiconductors and other sectors is intensifying.

Foreigners begin "selective buying" in autos, biotech, and secondary batteries
- What happened?: As the KOSPI stays at record highs, foreign interest is diversifying beyond semiconductors into autos, biotech, and secondary batteries. Analysis suggests foreigners are targeting this "triad" while semiconductors support the index floor.
- Market Impact: Increased foreign interest in auto stocks like Hyundai Motor and Kia, as well as some biotech firms; selective approach in secondary batteries.
KRW/USD exchange rate opens at 1,466.0 KRW, down 5.7 KRW
- What happened?: In the Seoul foreign exchange market on May 11, the KRW/USD rate opened at 1,466.0 KRW, down 5.7 KRW from the previous close. This shows a cooling trend after peaking at 1,471.7 KRW due to heavy foreign sell-offs.
- Market Impact: The shift toward a lower exchange rate (stronger Won) is acting as a positive factor for the market by easing foreign selling pressure.
Leading Sectors & Themes
Semiconductors (Samsung Electronics & SK Hynix)
- Trend: The core sector driving the 4% KOSPI surge. The direct cause of the buy-side sidecar. With a 43.9% share of monthly trading volume, it effectively dominates the market.
- Key Stocks: Samsung Electronics (+), SK Hynix (+), SK Square (+)
Semiconductor Value Chain, Power Equipment, Materials
- Trend: Gains in semiconductor giants spread to the wider value chain. Expectations for AI data center infrastructure are fueling speculative buying in power equipment and materials.
- Key Stocks: Power equipment-related stocks (hitting price limits), semiconductor materials (+).
Autos & Biotech (New beneficiaries of foreign interest)
- Trend: Foreign buying interest is broadening. Hyundai Motor Group is seeing net buying due to robot business expectations and earnings improvements. Selective foreign inflows also noted in biotech.
- Key Stocks: Hyundai Motor, Kia (+), major large-cap biotech stocks (selective gains).
Top Movers
Top 3 Gainers
- Cosmo Robotics: Quadruple (+300% from IPO price) — strong debut on the KOSDAQ.
- Samsung Electronics: Led intraday gains — driven by AI infrastructure demand and cumulative foreign buying.
- SK Hynix: Led intraday gains — driven by expectations of capturing the HBM/AI semiconductor market.
Top 3 Losers
- KOSDAQ Large-caps: -3.59p drop — capital flight toward KOSPI semiconductor stocks.
- Cosmetics-related stocks: Declining — high-net-worth investors shifting to "buy semiconductors, sell cosmetics."
- KOSDAQ General Small-caps: Widespread weakness — capital exiting toward KOSPI semiconductor plays.

Global Market Linkage
① Uncertainty over US-Iran peace talks — A major variable for the return of risk-on sentiment. While uncertainty persisted, expectations for negotiations rose on May 11, helping recover risk appetite.
② US Nasdaq AI semiconductor demand growth — A key driver for domestic semiconductor concentration. With the price-to-earnings ratio of Samsung Electronics and SK Hynix still considered low, it provides a logical basis for further foreign buying.
Tomorrow's Checkpoints
- KOSPI breaking 7,900: After holding at 7,880, monitor whether it can successfully breach 7,900 by the close.
- Shift in foreign sentiment: Monitor early morning trading to see if the heavy net selling from earlier this month shifts following the sidecar.
- US CPI and major earnings: Evaluate the impact of US CPI data and large corporate earnings on the exchange rate and semiconductor inflows.
Investor Action Items
- Check semiconductor positions: With Samsung and SK Hynix accounting for 44% of trading volume, monitor early-market signals for profit-taking or shifts in foreign selling.
- Look for KOSDAQ/small-cap opportunities: Check if the KOSDAQ’s decline has reached an oversold zone using technical indicators and foreign inflows.
- Monitor KRW/USD direction: Watch if the Won continues to strengthen (falling exchange rate) to gauge potential for foreign fund reentry and the impact on export-oriented sectors (semiconductors, autos).
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