[Closing 2026-03-17] KOSPI Surges on AI Chip Rally; SK Hynix Jumps
KOSPI Index · KOSDAQ Index
The South Korean stock market witnessed a notable divergence on Tuesday, March 17, 2026. While the benchmark KOSPI index staged a significant rally driven by a surge in heavyweight technology stocks, the secondary KOSDAQ market struggled to find its footing, eventually closing in negative territory. The primary catalyst for the KOSPI’s upward move was the growing optimism surrounding the global AI semiconductor industry, particularly with the upcoming NVIDIA GTC 2026 event.
AI Chip Rally Lifts Benchmark Index
The AI chip rally KOSPI investors had been anticipating finally materialized today. The KOSPI closed at 5,646.18, up 96.33 points or 1.74% from the previous session. This gains were largely concentrated in the semiconductor and technology sectors. Market participants are closely watching SK Group Chairman Choi Tae-won’s planned visit to NVIDIA’s GTC 2026, which is expected to yield new cooperation plans between the Korean chipmaker and the AI giant.
SK Hynix (000660), a critical supplier of High Bandwidth Memory (HBM) to NVIDIA, saw its share price surge by 7.03%. Similarly, SK Square (402340) jumped 5.24% on the back of the group’s semiconductor momentum. Samsung Electronics (005930) also contributed to the index’s strength, rising 2.83% as investors repositioned for a broader tech recovery.
KOSDAQ Pulls Back Amid Foreign Selling
In contrast to the KOSPI’s gains, the KOSDAQ index finished lower at 1,138.29, shedding 14.67 points or 1.27%. The decline was attributed to heavy selling by foreign investors who remains cautious about the broader economic outlook and currency volatility. While the tech giants on the main board attracted capital, small-to-mid-cap stocks on the KOSDAQ faced liquidity pressure.
Foreign investors were net sellers on Tuesday, a move that capped the potential for a market-wide rally. The selling pressure was particularly evident in the electric vehicle (EV) battery sector and parts manufacturers, which have seen fluctuating sentiment over the past few weeks. This divergence highlights a “selective rally” where capital is flowing into high-conviction AI themes while exiting more speculative or macro-sensitive sectors.
Market Data Summary: March 17, 2026
| Index | Closing Value | Change (%) | Change (Pts) |
|---|---|---|---|
| KOSPI | 5,646.18 | +1.74% | +96.33 |
| KOSDAQ | 1,138.29 | -1.27% | -14.67 |
Sector Performance and Key Movers
Beyond the semiconductor rally, the automotive and defense sectors showed signs of weakness. Hyundai Motor (005380) declined by 2.13%, and Kia (000270) dropped 1.4%, reflecting concerns over global demand and the strengthening won against some trading partners, even as the USD/KRW exchange rate remains high.
The defense sector, often seen as a beneficiary of geopolitical tensions, saw profit-taking. Hanwha Aerospace (-0.81%) and HD Hyundai Heavy Industries (-2.18%) were among the notable decliners as the “Middle East beneficiary” theme cooled off temporarily. Investors appear to be rotating funds back into growth-oriented tech stocks as the AI narrative regains dominance.
| Stock Name | Ticker | Closing Price | Change (%) |
|---|---|---|---|
| SK Hynix | 000660 | – | +7.03% |
| SK Square | 402340 | – | +5.24% |
| Samsung Electronics | 005930 | – | +2.83% |
| Hyundai Motor | 005380 | – | -2.13% |
| Kia | 000270 | – | -1.4% |
Macro Environment and Outlook
The Korean won closed at 1,497.5 against the US dollar, hovering near the psychologically important 1,500 level. This currency volatility remains a double-edged sword for the Korean market; while it benefits exporters like the chipmakers, it also raises concerns about imported inflation and the cost of raw materials. For a deeper dive into how currency shifts are affecting the bourse, see our latest report on Korean market trends for 2026.
Looking ahead, the market direction will likely be dictated by the opening remarks from NVIDIA’s GTC event and the subsequent reaction in US tech markets. If the partnership between Korean semiconductor firms and global AI leaders is further solidified, the KOSPI could test the next resistance level. However, the persistent foreign selling on the KOSDAQ suggests that a broad-based recovery may still be some time away.
Disclaimer: The information provided in this article is for informational purposes only and does not constitute financial or investment advice. Investing in the stock market involves risks, and investors should perform their own due diligence or consult with a professional advisor before making any investment decisions.