300 Points in a Single Day: KOSPI Closes at 6,307 as Samsung and SK Hynix Surge 7% to Set New All-Time Highs
On February 26, 2026, the KOSPI closed at 6,307.27, breaking through the 6,300 mark just one day after surpassing 6,000. Fueled by Nvidia's earnings surprise, Samsung Electronics (+7.13%) and SK Hynix (+7.96%) both hit all-time highs, driving the index up by 3.67%.
Korea's stock market made history twice today. Just one day after the KOSPI crossed 6,000, it broke through 6,300. Nvidia's earnings surprise ignited a global AI semiconductor rally, sending Samsung Electronics and SK Hynix up more than 7% and lifting the index by 3.67%.
TL;DR
- Closing price: 6,307.27 — up +223.41 points (+3.67%) from the previous day, a new all-time closing high
- Samsung Electronics +7.13% → ₩218,000 / SK Hynix +7.96% → ₩1,099,000 — both stocks hit all-time highs
- Hyundai Mobis +12%+ and other major parts and materials stocks also rose strongly
- Nvidia's Q4 FY2025 earnings surprise reconfirmed AI semiconductor demand → HBM suppliers Samsung and SK Hynix were direct beneficiaries
- Institutional net buying: ₩1.2438 trillion, retail net buying: ₩661.1 billion — foreigners took profits of ₩2.1099 trillion
- Bank of Korea announced the same day: 2026 growth forecast raised from 1.8% to 2.0%
The Facts — What Happened
On February 26, the KOSPI opened up 0.61% at 6,121.03 and rapidly extended gains during the session. After crossing the 6,303 line at 3:14 PM, the index closed at 6,307.27. This is a new all-time closing high, and a second record in just one day following the previous day's first-ever close above 6,000 (6,083.86).
| Category | Figure | Note |
|---|---|---|
| KOSPI Closing Price | 6,307.27 | All-time high |
| Change from Previous Day | +223.41 (+3.67%) | One of the largest single-session gains |
| Samsung Electronics | ₩218,000 (+7.13%) | New all-time high |
| SK Hynix | ₩1,099,000 (+7.96%) | New all-time high |
| Hyundai Mobis | +12%+ | Strong across the board |
| Institutional Net Buying | ₩1.2438 trillion | Dual buying support |
| Retail Net Buying | ₩661.1 billion | |
| Foreign Net Selling | ₩2.1099 trillion | Profit-taking |
Drivers of the Rally — Why Did It Rise So Fast?
1. Nvidia Earnings Surprise
Nvidia's Q4 FY2025 results, released after the U.S. market close on February 25 (Eastern Time), significantly beat expectations. With confirmation that AI accelerator (GPU/HBM) demand remains intact, buying flowed directly into SK Hynix and Samsung Electronics, the key HBM suppliers.
2. Bank of Korea Raises Growth Forecast to 2%
The same day, the Bank of Korea revised its 2026 economic growth forecast upward from 1.8% to 2.0%, an increase of 0.2 percentage points. This reflected a combination of strong semiconductor exports and signs of domestic demand recovery. Confirmation of growth momentum further boosted investor sentiment.
3. Dual Domestic Buying Structure
While retail investors (₩661.1 billion) and institutions (₩1.2438 trillion) were both net buyers, foreigners sold a net ₩2.1099 trillion. Domestic capital fully absorbed the foreign profit-taking. Analysts suggest that regulatory improvements — including the Commercial Act amendment (mandatory treasury share cancellation) and ETF diversification — are increasing incentives for domestic funds to remain invested in the KOSPI.
Context & Background — Why Did the KOSPI Break Out Now?
- September 2025 – February 2026: Commercial Act amendment discussions → mandatory treasury share cancellation confirmed → shareholder return expectations priced in
- February 25, 2026: KOSPI breaks 6,000 for the first time (closing at 6,083.86)
- February 26, 2026 (today): Nvidia earnings + BOK growth forecast upgrade combine to push through 6,300
- Samsung Electronics: AI order momentum re-highlighted following Q4 FY2025 turnaround in the DS (semiconductor) division
- SK Hynix: Near-monopoly position in HBM3E supply + expectations for next-gen HBM4 dominance
The core of this rally is that the market broke through both 6,000 — seen as a psychological resistance level — and 6,300 — seen as a technical resistance level — within just two days.
Outlook — Can the Rally Continue?
Bull Case (Target: 7,000)
- If the AI semiconductor supercycle continues through 2027, HBM demand increases → further EPS upgrades for Samsung and SK Hynix
- If the Korean won strengthens (USD/KRW below 1,400), foreign net buying could return
- Commercial Act amendment resolves 'Korea Discount' → room for PBR to converge toward 1x
Caution Signals
- Large-scale foreign profit-taking (₩2.1 trillion): Short-term supply pressure
- Trump tariff (15%) uncertainty — semiconductor exemption status unconfirmed
- KOSPI RSI and band indicators suggest possible short-term overheating
- BOK rate cut timing in Feb–March unclear → need to recalculate equity attractiveness vs. bonds/real estate
Investor Checklist
References
- KOSPI Breaks 6,300 Too... Samsung, SK Hynix Surge 7% (ZDNet Korea)
- KOSPI Surges 3.67%, Closes Above 6,300 for First Time (Yonhap News)
- BOK raises Korea's 2026 growth forecast to 2% (Korea JoongAng Daily)
- KOSPI Breaks 6,300 for First Time... Samsung, SK Hynix Up 7% (Seoul Shinmun)
Image Credit
- Yeouido Financial District, Seoul: Wikimedia Commons — CC BY-SA 2.0