Geopolitical Tension in Borsa Istanbul: BIST 100 Ends Day with Sharp Decline

Geopolitical Risks Trigger Sell-Off The BIST 100 index at Borsa Istanbul completed the trading day on February 19, 2026, with a sharp decline.
Starting the day at 14,340.28 points with a 0.56% increase compared to the previous close, the index came under intense selling pressure throughout the day due to reports of potential US intervention in Iran and escalating geopolitical tensions.
The BIST 100 index closed the Thursday session with a 3.20% loss, ending the day at 13,804.21 points.
Sectoral Performance and Trading Volume Declines were observed throughout the day, led by the banking and holding indices.
The banking index lost 4.13%, while the holding index decreased by 3.39%.
Among the sector indices, the only group to close in positive territory was the financial leasing and factoring sector with a 0.8% increase, while banking was the sector that lost the most.
The total trading volume in the market reached 117.8 billion lira.