Turkey's stock exchange fell 0.15 percent, or 142.16 points, to open at 94,354.64 points on Friday.
On the last transaction day of the week, the banking sector index gained 0.02 percent, while the holding sector index dropped 0.21 percent.
Among all sector indices, the BIST metal products machinery was the best performer, up 0.85 percent, while BIST wholesale and retail trade suffered the worst drop, down 0.94 percent.
On Thursday, Borsa Istanbul's BIST 100 closed at 94,496.80, down 2.77 percent, or 2,691.07 points, with a trading volume of 7.3 billion Turkish liras (around $1.18 billion).
The USD/TRY exchange rose to 6.1990 as of 9.30 a.m. local time (0630GMT) on Friday, compared to 6.1490 at the previous close.
The EURO/TRY exchange climbed to 7.1330 by market open, versus 7.1020 at the previous close. One British pound traded for 8.0900 Turkish liras -- from 8.0120 on Thursday's close.
The price of Brent oil stood at $85.06 per barrel as of 10.15 a.m. local time (0715GMT) Friday, compared to $85.72 on Thursday, while it was around $66 at the beginning of 2018.
Turkey's Borsa Istanbul down at open
BIST 100 index falls 0.15 percent from previous close