Turkey's benchmark stock index ended the week down 0.17% to close at 88,533.40 points on Friday.
After starting the last business day of the week at 89,480.41 points, Borsa Istanbul's BIST 100 index fell 152.48 points from 88,685.88 points at Thursday's close.
On a weekly basis the benchmark index posted a 5.76% decline, standing at roughly the same level compared to 88,865.01 points at the close on the first business day of 2019.
During Friday's trading, the BIST 100 hovered between 88,315.54 points and 89,855.50 points -- 44 stocks on the index rose, 48 fell, and eight were flat compared to the previous close.
Closing the day with a market value of nearly 588 billion Turkish liras ($95 billion), the benchmark index posted a daily trading volume of 5.56 billion Turkish liras ($908 million).
By market capitalization, Turkish conglomerate Koc Holding ($6.34 billion), private lenders Garanti BBVA ($5.19 billion) and Akbank ($4.77) were the leading companies of BIST 100.
Shares of national flag carrier Turkish Airlines, Garanti BBVA, and leading petrochemicals producer Petkim recorded the highest trading volumes on Friday -- accounting for around 43% of the benchmark index's total trade volume.
Stocks of energy and construction company Isiklar Enerji Yapi Holding (IEYHO) showed the top performance -- up 8.33% -- as shares of prominent airport operator TAV Airports Holding (TAVHL) fell the most with a 3.93% decline.
One ounce of gold was sold for $1,288.60 at the daily close in Borsa Istanbul's Precious Metals and Diamond Markets, versus $1,283.05 at the previous close.
The price of Brent oil was $70.56 per barrel as of 6.15 p.m. local time (1515GMT) on Friday -- with a day range of $70.17 to $71.22.
At the beginning of 2019, a barrel of Brent oil was sold for around $53.
Source: Anadolu Agency