Turkey's benchmark stock index started Friday with a 92.92-point or 0.09 percent drop to open at 108,298.80 points.
The banking and holding sector indices fell by 0.13 and 0.02 percent, respectively.
Among all sectors, the mining sector index was the best performer, up one percent, while the insurance sector index started the day with the biggest decline, falling 1.51 percent.
Turkey’s benchmark stock index closed Thursday up 1.11 percent at 108,391.71 points -- its highest ever close.
The BIST 100 rose 1,185.55 points with a total trading volume of five billion Turkish liras (around $1.41 billion).
The U.S. dollar/Turkish lira exchange rate climbed to 3.5340 at 9.30 a.m. local time (0630GMT) Friday, compared with 3.52 at Thursday's close.