The Straits Times Index (STI) dropped 1% on Tuesday morning as investors reacted to the escalation of US-Iran tensions.
President Donald Trump announced the reinstatement of a naval blockade on Iranian ports and outlined a new 20% toll for transit through the Strait of Hormuz, signaling a significant hardening of the geopolitical stance toward Tehran.
The market sell-off was broad but particularly acute for companies with direct exposure to regional shipping and energy flows.
Keppel, Sembcorp, and Singapore Airlines (SIA) all posted declines, reflecting investor concerns over potential route disruptions and rising insurance premiums in the Persian Gulf corridor.
The Strait of Hormuz remains a critical chokepoint for global energy supplies, and any impediment to transit threatens to spike freight costs and oil prices.
This development follows a period of heightened volatility in US equity markets, which closed lower on Monday after the initial announcement of the blockade.