The benchmark Korea Composite Stock Price Index(KOSPI) broke the four-thousand mark for the first time during Monday's session.

The main bourse opened at three-thousand-999-79, up one-point-48 percent from Friday's closing, and quickly surpassed the four-thousand mark.

It comes about four months after the index surpassed the three-thousand-point mark on June 20 for the first time in three and a half years.

As of 11:42 a.m., the KOSPI climbed two-point-35 percent from Friday’s closing to four-thousand-34-point-37. 

Samsung Electronics, the largest company by market capitalization on the KOSPI, also topped 100-thousand won for the first time shortly after the market opened.