Turkey's benchmark stock index went down 0.48 percent or 453.62 to open at 93,245.87 points on Monday.
On Friday, Borsa Istanbul's BIST 100 index increased 0.94 percent to close the week at 93,699.49 points with a daily trading volume of 5.26 billion Turkish lira ($985.2 million).
The U.S. dollar/Turkish lira exchange rate was flat at 5.2930 as of 9.30 a.m. local time (0630GMT), compared with Friday's closing rate of 5.2940.
The euro/Turkish lira exchange rate was 6.0580, versus 6.0280 at the last close. One British pound traded for 6.7610 Turkish liras, as the GBP/TRY exchange rate was 6.7640 by market close on Friday.
The price of Brent oil rose to $61.92 per barrel as of 10.00 a.m. local time (0700GMT) Monday, versus $61.67 on Friday's closing.