The KOSPI on Sunday ended up more than 1 percent, regaining the 5,450 level on net buying by institutions. The KOSDAQ, however, fell more than 1 percent to end weaker.

The KOSPI closed up 73.03 points, or 1.36 percent, at 5,450.33. It opened at 5,423.35 and rose as high as 5,505.61 before giving up some gains. The day's low was 5,404.91.

By investor type, institutions were the sole net buyers, purchasing 836.5 billion won worth of shares to lead the index higher. Individuals and foreigners sold 1.05 trillion won and 159.7 billion won, respectively.

Top market-cap stocks were mixed. Samsung Electronics rose 3.71 percent to end at 193,100 won, and SK Hynix gained 1.14 percent to close at 886,000 won.

LG Energy Solution rose 3.51 percent, while Hanwha Aerospace added 0.07 percent. Samsung Biologics rose 0.06 percent, SK Square gained 0.83 percent, Kia rose 0.93 percent and KB Financial Group added 1.65 percent.

Hyundai Motor fell 0.42 percent and Doosan Enerbility dropped 0.93 percent.

The KOSDAQ closed down 16.38 points, or 1.54 percent, at 1,047.37.

In the Seoul foreign exchange market, the won-dollar exchange rate stood at 1,507.00 won in real-time trading, down 3.10 won, or 0.21 percent, from the previous session.