KOSPI Hits 2021 High Correlation with Nasdaq-100 at 0.50 as AI Drives U.S.-South Korea Market Linkage

According to analysts at Futurum Group and other financial institutions, the 60-day correlation coefficient between South Korea's KOSPI index and the Nasdaq-100 index has recently risen to approximately 0.50, marking the highest level since 2021. This increased correlation reflects the growing importance of Samsung Electronics and SK Hynix, which together now account for over 50% of KOSPI's index weight. Both companies sit at the core of the AI hardware supply chain, providing memory chips essential for U.S. tech giants' data centers. Rolf Bulk, analyst at Futurum Group, stated that the correlation increase is driven by KOSPI effectively becoming a semiconductor index.

The linkage was evident on July 13, when KOSPI plunged over 8% following SK Hynix's 15% crash, marking its largest single-day decline on record. On the same day, Nasdaq-100 dropped 1.88%, with major U.S. tech stocks falling in tandem: Micron (MU-US) down 4%, SanDisk (SNDK-US) down 12%, and Intel (INTC-US) down 6%.