KOSPI reclaimed the 6,000 mark intraday on April 14 but failed to hold it and finished in the 5,900 range. The last time it closed above 6,000 was 6,244.13 on Feb. 27, the trading day just before the outbreak of the U.S.-Iran war.

KOSPI ended up 159.12 points, or 2.74 percent, at 5,967.74 from the previous session. The index opened at 5,960.00, up 151.38 points, or 2.61 percent, and rose as high as 6,026.52. It was the first time in 30 sessions that it touched 6,000.

By investor type, foreigners were net buyers of 862.5 billion won worth of shares and institutions bought a net 1.22 trillion won, driving the index higher. Individuals dumped 2.39 trillion won worth of shares onto the market.

Most top market-cap stocks rose. Samsung Electronics closed up 2.74 percent at 206,500 won, and SK Hynix finished 6.06 percent higher at 1,103,000 won.

Hyundai Motor rose 2.72 percent, SK Square climbed 10.34 percent, Doosan Enerbility added 0.40 percent and Kia gained 1.22 percent.

LG Energy Solution fell 0.37 percent, Hanwha Aerospace slipped 0.46 percent and Samsung Biologics dropped 0.90 percent.

KOSDAQ ended up 22.04 points, or 2.00 percent, at 1,121.88 from the previous session.

The won-dollar exchange rate ended at 1,481.10 won, up 0.60 won from the previous session.