Asian stock markets saw a substantial downturn on Monday, with Japan's Nikkei index plunging by 4.7% and the broader Topix index decreasing by 4.3%. Similarly, South Korea's Kospi index fell by 5.3%, reflecting widespread investor concern over economic stability in the region. This market reaction is largely attributed to escalating tensions in the Iran conflict, driving oil prices higher and impacting investor sentiment.

The decline in Asia's major stock indices coincides with a notable fall in the South Korean won, which has reached its lowest value against the US dollar in 17 years. This depreciation of the currency raises concerns about the economic pressures the South Korean market is facing and reflects investor anxiety over the potential wider implications of rising oil prices. The fall of the won not only affects currency markets but can also lead to increased costs for imports, which may result in inflationary pressures within the country.

In addition to Japan and South Korea, the Hong Kong market also reported losses, with the Hang Seng index dropping nearly 3% at the open, while Shanghai's main index fell around 2%. The situation in Asia’s financial markets underscores the increasingly volatile economic landscape driven by geopolitical tensions and rising oil prices, prompting investors to reassess their positions as uncertainty looms over future market performance.