Key facts
- The Nikkei 225 index reached an all-time high on June 18, 2026.
- The KOSPI index reached an all-time high on June 18, 2026.
- Investor enthusiasm for artificial intelligence drove market rallies.
- Hopes for geopolitical de-escalation contributed to market gains.
- A U.S.-Iran deal was cited as a factor in geopolitical de-escalation.
- Positive corporate earnings reports bolstered investor confidence.
- Both benchmarks reached unprecedented levels.
On June 18, 2026, both Japan's Nikkei 225 and South Korea's KOSPI stock indices reached all-time highs. This significant market achievement was attributed to a confluence of positive factors, primarily driven by robust investor optimism surrounding the artificial intelligence sector. The burgeoning potential and advancements in AI technology have captured the attention of global investors, leading to increased investment in related companies and sectors.
In addition to the AI boom, a perceived de-escalation in geopolitical tensions provided further impetus for the market rallies. Specifically, hopes for increased stability followed a reported U.S.-Iran deal, which eased concerns about potential conflicts and disruptions in key global regions. This reduction in geopolitical risk is often a catalyst for increased investor confidence and a willingness to allocate capital to equity markets.