The KOSPI Rally Continues as SK Hynix & Samsung Shares Lead

The KOSPI index continued its impressive ascent, closing at 4,105.93 as substantial gains in the index heavyweights continued the ‘year of the KOSPI'. The South Korean benchmark index has now achieved a remarkable year-to-date increase of 71.16%, showcasing the strength of the local equity market, with the big names more than pulling their weight.

Samsung Electronics (KRX: 005930) saw its shares climb 3.95%, moving into a double year-to-date, with the share price up 106.93% since the start of 2025. However, the standout performer remains SK Hynix, whose shares surged by an impressive 6.03% to bring it's own YTD gain to an astounding 238.79%, positioning it as a key driver of the KOSPI's overall success.

Several factors have converged to create this bullish environment. One pivotal element is the strategic partnerships forged between Samsung Electronics and SK Hynix with OpenAI. These collaborations, announced in early October 2025, involve supplying memory chips for OpenAI's expansive “Stargate” artificial intelligence data center project.

These partnerships not only underscore the critical role of these companies in the AI sector but also bolstered market confidence, leading to substantial stock price increases. Immediately following the announcement, Samsung's shares jumped 4.7%, while SK Hynix soared 12%, collectively adding $37 billion to their market capitalization.

SK Hynix's financial performance has further supported the upward move. The company reported record-breaking third-quarter earnings, with operating profits exceeding KRW 11 trillion. This impressive performance was driven by robust global demand for high-bandwidth AI memory, highlighting the company's pivotal position in the semiconductor supply chain.

Moreover, SK Hynix's commitment to innovation in the AI sector has resonated positively with the markets. In late October, the company unveiled plans for its next-generation AI-NAND (AIN) product lineup, designed to meet the rapidly growing demand for AI-specific memory solutions. This announcement contributed to a 4% increase in its share price, reaching a record high of 537,000 won.

The broader technology sector has played a crucial role in propelling the KOSPI to new heights. Nvidia's CEO expressed intentions to strengthen cooperation with Korean chipmakers, further boosting market confidence in Samsung and SK Hynix; whilst easing trade tensions between the U.S. and China and expectations of U.S. interest rate cuts have created a more favourable macroeconomic environment. 

The performance of bellwether stocks such as SK Hynix and Samsung will continue to be closely monitored as markets assess the sustainability of this upward trend heading into the new year.