Investing.com — South Korea’s $4 trillion equity market has become an important early indicator of global risk appetite, as swings in Samsung Electronics Co Ltd () and SK Hynix Inc () spread across semiconductor and artificial intelligence stocks, Bloomberg reported.

Fund managers in London, New York and Tokyo are increasingly monitoring the before their domestic markets open. The index provides an early indication of sentiment toward memory chips and AI infrastructure spending.

That influence reflects the central role Samsung and SK Hynix play in global semiconductor supply. Both companies produce high-bandwidth memory used alongside AI accelerators from NVIDIA Corporation () and other chip designers.

The relationship with US stocks has strengthened sharply. The 60-day correlation between the Kospi and reached 0.46, close to a two-year high and nearly three times its five-year average of 0.16.

Korean market declines have had an even greater effect. The Nasdaq 100’s sensitivity to below-trend Kospi returns recently climbed to its highest level since 1990, with a similar measure for the MSCI World Index reaching a four-year high.

Last week, concerns about future AI demand sent the Kospi down nearly 9% in one session before the selling reached Wall Street. SK Hynix’s US-listed depositary receipts fell 9.3%, pulling other major chipmakers lower.

Its American listing and Korea-focused exchange-traded funds now allow investors to track the market’s AI exposure across most of the global trading day.

Leverage has amplified those movements, making the Kospi one of the most volatile major equity benchmarks. South Korea temporarily halted new listings of single-stock leveraged exchange-traded products to curb speculative activity.

The Kospi has fallen 25% from its June peak, wiping about $1 trillion from its value. Samsung and SK Hynix have each lost at least 30% during the pullback.

Despite the correction, the benchmark remains up 62% in 2026, keeping it among the world’s strongest-performing major markets.