Helped by record-setting results from Samsung Electronics and SK Hynix, the KOSPI on Jan. 29 ended above the 5,200 mark for the first time.

The KOSPI closed up 50.44 points, or 0.98 percent, at 5,221.25.

The index opened up 72.61 points, or 1.40 percent, at 5,243.42 and jumped to as high as 5,252.61 shortly after the open. It then began to fall sharply, slipping to 5,073.12 at one point in the morning.

It later reversed course and recouped losses rapidly, regaining the 5,200 level in the afternoon.

Retail investors alone bought 1.62 trillion won net, lifting the index. Foreigners sold 1.51 trillion won net to lock in profits, and institutions also sold 150.2 billion won.

Just before the domestic market opened, Samsung Electronics released record-setting earnings.

On a consolidated basis, its operating profit for last year was preliminarily tallied at 43.6 trillion won, up 33.2 percent from a year earlier, and revenue rose 10.9 percent to 333.6 trillion won.

Annual revenue was the highest on record, while operating profit ranked fourth after 2018 (58.89 trillion won), 2017 (53.65 trillion won) and 2021 (51.63 trillion won).

In the domestic market that opened in that atmosphere, Samsung Electronics surged 2.59 percent early to as high as 166,600 won.

It soon turned lower and fell to 157,100 won, down 3.26 percent, at one point. It narrowed losses to end down 1.05 percent at 160,700 won.

SK Hynix, which announced record-high results after the previous session’s close, showed a similar share-price pattern, but ultimately ended up 2.38 percent at 861,000 won.

A 'sell-on' effect from materialising catalysts pushed prices down sharply, but bargain buying flowed in, limiting losses or driving a rebound.

Other top market-cap stocks had mixed performances.

Hyundai Motor rose 7.21 percent, SK Square gained 5.36 percent, Kia added 3.47 percent, Naver climbed 3.42 percent and Doosan Enerbility rose 2.17 percent. LG Energy Solution fell 3.36 percent, Celltrion slipped 1.83 percent and Samsung Biologics lost 0.84 percent.

The Kosdaq ended up 30.89 points, or 2.73 percent, at 1,164.41.

The index opened up 19.91 points, or 1.76 percent, at 1,153.43 and slipped to as low as 1,108.43 at one point, before quickly recouping losses and turning higher.

Amid a continued rally, the Kosdaq’s rise since the start of the year stood at 25.8 percent as of the closing price on the day, surpassing the KOSPI’s 23.9 percent to rank first among major global stock markets.