By Aysu Bicer
ANKARA (AA) - Turkey's benchmark stock index started the week at 1,054.55 points on Monday, down 0.57% or 6.05 points.
At Friday's close, Borsa Istanbul's BIST 100 index was up by 2.53% at 1,060.59 points with a daily trading volume of 25 billion Turkish liras ($3.4 billion).
The US dollar/Turkish lira exchange rate stood at 7.3190 as of 9.30 a.m. local time (0630GMT), up compared to 7.2030 at the previous close.
The euro/Turkish lira exchange rate also rose to 8.6290 from 8.4830, while the British pound traded for 9.5780 Turkish liras, up from 9.4140.
One barrel of Brent crude oil sold for around $44.88 as of 10.00 a.m. local time.
Meanwhile, Borsa Istanbul on Monday announced it would implement a market-wide circuit breaker system (MWCB system) for the first time, in addition to its current instrument-based system in the equity market.
The MWCB will halt trade during the day in the case of a fall compared to the previous closing value in the BIST 100 Index of 5% or more as its first threshold and 7% or more as the second.
Trading in the BIST 100 will be halted for up to 20 minutes if stocks suddenly dive 5-7 percent below the previous close, according to a statement.
After a 20-minute circuit breaker stop, orders will be collected in the following five minutes.
Borsa Istanbul had put a stock-based circuit breaker system into effect in 2015, replacing another system halting a session completely.
When the MWCB is activated, trading will halt temporarily in the equity market, as will equity and equity index contracts in the derivatives market and in the debt securities equity repo market.
Circuit breakers are regulatory measures to temporarily halt trading on an exchange in case of sudden fluctuations.