Turkey's benchmark index started the day with a 361.79-point increase to open at 91,165.92 points on Thursday.
On the fourth transaction day of the week, the BIST 100 index rose by 0.40 percent.
The banking and holding sector indices went up by 0.70 percent and 0.15 percent, respectively.
Among all sectors, the banking sector index was the best performer while the insurance index started the day with the biggest decline, falling by 0.64 percent.
The BIST 100 was down 569.65 points or 0.62 percent to reach 90,804.13 with a total trading volume of 5.8 billion Turkish liras ($1.58 billion) at close on Wednesday.
The U.S. dollar/Turkish lira exchange rate declined to 3.6670 at 9.30 a.m. local time (0630GMT) Thursday, compared with 3.6700 at Wednesday's close.
Meanwhile, Turkey's consumer confidence and non-domestic producer price indexes were announced on Thursday.
According to the Turkish Statistical Institute, Turkey's consumer confidence index increased by 5.1 percent to 71.3 points in April, compared to 67.8 in March.
The central government's domestic and external debt statistics are set to be released by Turkey's Treasury Undersecretariat on Thursday. -