Nigeria’s stock exchange introduced a circuit breaker to limit price fall as equities plunged the second-most among global stock markets this week.

Trading on the Nigerian Stock Exchange will be stopped for 30 minutes if the All Share Index moves 5% from the previous day’s close between 10:15 a.m. and 1:45 p.m., the bourse said in a statement on its website. The market will close for the day if the circuit breaker is triggered for a second time or after 13:45 p.m.

The implementation of the rule, originally approved by Nigerian authorities in May 2014, came as the market experienced its sixth day of losses.