South Korea's KOSPI (the country's benchmark stock index) closed above 9,000 for the first time on June 18, finishing at 9,063.84, up 199.60 points or 2.25%, according to Seoul Economic Daily and Chosun Biz. The milestone headline, however, masks the question a global allocator should ask first: was this a broad re-rating of Korean equities, or a two-stock semiconductor melt-up that the rest of the market sat out?
The breadth data points to the latter. Samsung Electronics (005930.KS), the world's largest memory chipmaker, rose 4.62% and SK Hynix (000660.KS), Korea's second-largest chipmaker and the leading supplier of high-bandwidth memory, jumped 6.51%, per Seoul Economic Daily. Yet on the same session only 112 KOSPI stocks advanced while 791 fell, and the tech-heavy KOSDAQ (Korea's secondary market) sank 3.01% to close at 1,000.93. Businesskorea reports that Samsung and SK Hynix together now account for more than half of the KOSPI's market capitalization — a combined 54.76% — meaning the index can set records while the median Korean stock declines.
What is moving the chipmakers
The immediate catalyst came from the supply side: Chosun Biz reports SK Hynix has begun shipping samples of its next-generation HBM4E 12-layer memory, reinforcing the AI-memory shortage narrative. SK Hynix touched an intraday record of ₩2,738,000 (~USD2,000) before closing at ₩2,685,000 (~USD1,960). Brokerages have been chasing the move with higher targets — Chosun Biz notes the most aggressive, from SK Securities (a Korean brokerage), now stands at ₩610,000 (USD445) for Samsung and ₩4,000,000 (USD2,920) for SK Hynix. At the index level, Goldman Sachs lifted its 12-month KOSPI target to 12,000 from 9,000, per Chosun Biz.
A flows picture that breaks the old rulebook
The rally has overturned a two-decade convention that Korean stocks rise only when foreigners buy. Citing Korea Exchange (KRX, the national bourse operator) data, Chosun Biz reports that from early May through June 18 foreign investors net sold ₩64.73 trillion (USD47.2 billion) of KOSPI shares — including ₩27.12 trillion (USD19.8 billion) of Samsung and ₩24.32 trillion (USD17.8 billion) of SK Hynix — while retail investors net bought ₩52.25 trillion (USD38.1 billion), absorbing the supply. Meritz Securities analyst Hwang Soo-wook attributed the foreign selling to mechanical rebalancing as prices ran ahead, not a bearish call, telling Chosun Biz that foreigners' ownership ratio has actually risen.
What could break it
The sustainability case rests on chip earnings holding up against tightening global liquidity. The Bank of Japan raised its policy rate to 1% on June 16, its highest since 1995, and the European Central Bank lifted its deposit rate to 2.25% from 2%, with the Bank of Korea (Korea's central bank) signaling a hike next month, per Chosun Biz. The market has already shown it is sensitive to AI-demand wobbles: Chosun Biz recalls that in April an OpenAI comment about slower revenue growth sparked a global tech sell-off, and on June 3 Broadcom's next-quarter AI revenue guidance of USD16 billion fell short of the roughly USD17.2 billion consensus, dragging chip names down worldwide.
Two near-term events will test the thesis. MSCI (the global index provider) is due to decide on Korea's developed-market reclassification in late June — Chosun Biz frames it as the single biggest swing factor for foreign flows. After that, the second-quarter earnings season will show whether profit growth is genuinely broadening beyond the two chipmakers, or whether "peak-out" worries that several analysts flagged to Chosun Biz begin to bite.
This article is for informational purposes only and does not constitute investment advice. Figures are sourced from Chosun Biz, Seoul Economic Daily and Businesskorea as cited; currency conversions use an approximate rate of 1 USD = 1,370 KRW.
Sources
- https://biz.chosun.com/stock/stock_general/2026/06/18/JKQ3GDNNANHCHLQIIGWDWLKNI4/
- https://biz.chosun.com/stock/analysis-prospect/2026/06/18/6OEVAGVE4RDF7O3V3GQXN4VK7U/
- https://biz.chosun.com/stock/stock_general/2026/06/18/EE5LPWAAHBBCJA3QCH7YWSTIGQ/
- https://biz.chosun.com/stock/stock_general/2026/06/18/6LRR5UEB4RC6NHEAUKIQFHHDUQ/
- https://www.koreatimes.co.kr/economy/20260618/kospi-tops-another-historic-milestone-9000-on-chip-rally
- https://en.sedaily.com/finance/2026/06/18/kospi-tops-9000-for-first-time-as-chip-less-retail
