Borsa Istanbul Closes Down 0.71% as Iran Tensions Weigh on Markets

The BIST 100 index closed Monday's session at 14,484.91 points, down 0.71%, as escalating US-Iran tensions rattled global risk appetite and pressured emerging-market equities. Concerns over shipping disruptions in the Strait of Hormuz and the uncertain outcome of US-Iran peace talks pushed investors toward caution.

For Turkey, which relies heavily on energy imports, renewed volatility in crude oil prices adds pressure to the current account and the lira. President Trump's threats to strike Iranian infrastructure if no nuclear deal is reached have clouded the outlook for a rapid de-escalation, keeping regional risk premiums elevated.

The decline coincided with the government's release of public debt data showing Turkey's central government gross debt stock reached 14.4 trillion lira at end-March. Traders will be watching the trajectory of US-Iran diplomacy this week as a key determinant of sentiment across emerging markets including Turkey.