BIST 100 Falls 1.08% on US Inflation Data

Turnover reached 86.1 billion lira, showing investors stayed active even as they trimmed exposure. Insurance was the only notable gainer among sector indices, rising 0.65%, suggesting a defensive bid as traders rotated away from rate-sensitive names.

The trigger was September US inflation, which rose 3.7% annually, above expectations and enough to strengthen the case for another Fed rate increase. For Turkey, that matters because tighter US policy tends to support the dollar, pressure capital flows into emerging markets and weigh on domestic risk assets already sensitive to funding costs and policy credibility.

Domestic headlines also kept investors cautious. Finance Minister Mehmet Simsek authorized an investigation into former Capital Markets Board chairman Ibrahim Omer Gonul following a preliminary inspection report, adding another layer of uncertainty around the regulatory backdrop.

For traders, the immediate focus is whether the BIST 100 can hold 12,100 and then 12,000, levels analysts flagged as support. Resistance is seen at 12,300 and 12,400, with coming data from the Central Bank of the Republic of Turkey and key US retail sales, producer prices and jobless claims likely to determine whether the selloff deepens or stabilizes.