Kospi locks in 5,000 as chip shares jump

South Korea’s benchmark Kospi wrapped up above the 5,000 mark Tuesday, clinching the psychological threshold on a closing basis for the first time.

The country's chip giants led the gains, with SK hynix reaching 800,000 won ($550), and Samsung Electronics hovering just below 160,000 won.

The index wrapped up the session at a record high of 5,084.85 on the day, advancing 2.73 percent from the previous session. It marked the first time the index finished above the level, after touching the milestone intraday on Thursday.

The Kospi opened at 4,932.89, down 0.34 percent on-session, and at one point slid to as low as 4,890.72, slipping below the 4,900 level. It later pared losses and turned higher, climbing above 5,000 during morning trading and managed to hold the line until the close.

Foreigners snapped up 850 billion won worth of stocks on the main market, with institutions adding 237 billion won. Individual investors offloaded shares worth 1 trillion won.

Tech giants SK hynix and Samsung Electronics drove the gains, each setting fresh highs.

SK hynix edged lower in early trading before extending gains to close up 8.7 percent at 800,000 won. It was the first time for the share to touch the 800,000 won mark.

Samsung Electronics opened down 1.05 percent at 150,500 won and slid nearly 2 percent in early trading, but reversed course to finish up 4.87 percent at 159,500 won, just shy of the 160,000 won mark.

With a combined market cap of 1,527 trillion won, roughly 36 percent of the Kospi’s total valuation of 4,204 trillion won, the two blue-chip shares wield significant influence over the broader market.

Hyundai Motor and Kia pared losses after plunging more than 4 percent in early trading, following US President Donald Trump’s unexpected announcement of plans to raise “reciprocal” tariffs on Korea from 15 percent to 25 percent.

Hyundai Motor closed down 0.81 percent at 488,500 won, while Kia fell 1.1 percent to end at 153,500 won.

“Auto shares came under pressure after Trump's remarks on possible tariff hikes, but losses narrowed on expectations that the impact would be limited and hopes for a robot-driven valuation rerating,” Lim Jung-eun, analyst at KB Securities, said.

Korea's secondary bourse, the Kosdaq, extended gains on Tuesday after reclaiming the 1,000-point milestone for the first time in four years in the previous session.

The Kosdaq closed at 1,082.59, advancing 1.71 percent on-session.

Alteogen, the Kosdaq’s bellwether stock, added 0.49 percent after gaining more than 9 percent over the previous two sessions, marking its third straight day of advances. It closed at 408,000 won.