South Korea's KOSPI index closed up 5.42% at 8,930 points this Thursday following record earnings from U.S. semiconductor company Micron Technology [1].

The surge reflects the deep interdependence between U.S. chip designers and South Korean manufacturers, as Micron's growth signals a massive recovery in global memory demand.

Micron Technology reported an unprecedented revenue jump of 345% [1]. This financial windfall acted as a catalyst for the South Korean market, lifting the KOSPI by more than five% during intraday trading [1]. The index briefly crossed the 9,000-point mark before settling just below that threshold at the close [1].

Major Korean semiconductor firms saw significant gains. Samsung Electronics shares rose five%, while SK Hynix saw a steeper increase of 13% [1]. These two companies serve as the primary pillars of the KOSPI, meaning their individual performance often dictates the direction of the broader national market.

"The announcement of record-breaking results from the US semiconductor company Micron has ignited the upward momentum of the KOSPI," an anchor for YTN said [1].

The market volatility highlighted the scale of the rally. A reporter for YTN said that because Samsung Electronics and SK Hynix surged, the index recovered the 9,000-point level during the day and ended the session nearly at that mark [1].

This rally comes as the global tech sector monitors the stability of the semiconductor supply chain, and the continuing demand for high-bandwidth memory used in artificial intelligence applications.

“KOSPI closed up 5.42% at 8,930 points”

The KOSPI's sensitivity to Micron's earnings underscores the systemic link between US chip demand and South Korean industrial health. Because Samsung and SK Hynix dominate the global memory chip market, a revenue surge at a US peer like Micron serves as a leading indicator for the entire sector's profitability, triggering massive capital inflows into the Seoul exchange.