The benchmark Korea Composite Stock Price Index(KOSPI) again set a new closing high on Wednesday, breaking the five-thousand-370 mark. 

The KOSPI gained 83-point-02 points, or one-point-57 percent, to close at five-thousand-371-point-10.

The index opened down 27-point-37 points, or zero-point-52 percent from Tuesday at five-thousand-260-point-71 but then surged sharply to surpass the five-thousand-300 mark before climbing further to break the previous closing high of five-thousand-288-point-08 posted the previous day.

Institutional investors bought a net one-point-78 trillion won worth of shares, driving the record-setting index, while foreigners and retail investors offloaded a net one trillion won and 940 billion won, respectively.

Samsung Electronics rose zero-point-96 percent to 169-thousand-100 won, while SK hynix lost zero-point-77 percent to 900-thousand won.

The tech-heavy KOSDAQ gained five-point-31 points, or zero-point-45 percent, to close at one-thousand-149-point-43.

The South Korean won weakened against the U.S. dollar by four-point-eight won, trading at one-thousand-450-point-two won as of 3:30 p.m.