Kospi Rebounds on SK Hynix AI Memory Surge as Brent Holds Steady Amid US-Iran Strikes

The Quick Take

• South Korea's Kospi index rebounded, led by SK Hynix surging on continued AI memory demand tailwinds, while Japan's Nikkei was little changed amid cautious global sentiment.
• Brent crude held relatively steady despite fresh US military strikes against Iranian targets, as traders priced in limited near-term supply disruption risk through the Strait of Hormuz.
• Asian equity markets showed regional divergence reflecting different sector compositions, with Korea's semiconductor-heavy index outperforming Japan's more broadly diversified Nikkei.

Asian equity markets exhibited divergent performance in early September 2026, with South Korea's Kospi leading regional gains while Japan's Nikkei consolidated. The primary driver of South Korea's outperformance was SK Hynix, whose shares surged on continued evidence that AI memory demand — particularly for high-bandwidth memory used in data center accelerators — is sustaining elevated pricing and order book momentum. The divergence between Seoul and Tokyo reflects the different sector compositions of each index: Korea is more heavily weighted toward semiconductors, while Japan's Nikkei is more broadly diversified across industrials, consumer, and financials with a different sensitivity profile to global macro news.

Oil markets showed resilience in the face of renewed geopolitical tension following US military strikes on Iranian targets near the Strait of Hormuz. Brent crude's muted reaction suggests commodity traders believe the strikes are contained in scope and do not threaten a major supply disruption through the strait — the critical chokepoint for roughly 17 million barrels per day of global oil flow. This interpretation is consistent with options market implied volatility, which has not spiked dramatically. The risk remains asymmetric: a wider escalation that closes or partially disrupts the Strait even temporarily would send crude prices sharply higher, with immediate knock-on effects for Asian energy import costs.

Key forward signals include US economic data releases expected later in the week, which investors in both Tokyo and Seoul markets are monitoring for signals on Federal Reserve policy direction. A stronger-than-expected US jobs report or inflation print could tighten global rate expectations, pressuring Asian equity multiples. On the geopolitical front, watch whether US-Iran tensions escalate to include Strait of Hormuz shipping disruptions — the macro tail risk most likely to override the positive SK Hynix semiconductor narrative and drive a broader risk-off episode across Asian markets in the near term.

Synthesized from 1 source.