A circuit breaker kicked in on the tech-heavy KOSDAQ on Friday for the first time in four years and six months, as the index plunged more than eight percent during the day. 

The South Korean secondary stock index plummeted more than eight percent to its yearly low of 594-point-75 points, the lowest since February tenth last year.

The last time a circuit breaker was put in place was August eight and ninth in 2011, when the market crumbled due to the United States' downgraded credit rating.

Earlier on Friday, a 5-minute sidecar was implemented on the KOSDAQ after the bourse dropped more than five percent from Thursday.