An electronic board showing the Korea Composite Stock Price Index at a dealing room of the Hana Bank headquarters in Seoul on Thursday. (Yonhap)
An electronic board showing the Korea Composite Stock Price Index at a dealing room of the Hana Bank headquarters in Seoul on Thursday. (Yonhap)

South Korean stocks opened sharply higher Thursday, set to extend their record-breaking bull run, backed by strong earnings results from the country's major chipmakers.

The benchmark Korea Composite Stock Price Index rose 55.81 points, or 1.08 percent, to 5,226.62 in the first 15 minutes of trading.

Before the market opened, Samsung Electronics said its fourth-quarter operating profit nearly tripled on-year, bolstering market optimism for the artificial intelligence sector.

Its rival SK hynix also announced record-breaking fourth-quarter earnings results a day earlier, boosted by a boom in AI chips.

Overnight, US stocks closed mixed, as investors digested the latest rate-freeze decision by the Federal Reserve ahead of earnings releases from major big tech companies.

The S&P500 closed 0.01 percent lower after hitting an all-time high. The tech-heavy Nasdaq rose 0.2 percent.

The US central bank held the country's base rate steady.

Fed Chair Jerome Powell said the US economy is growing at a "solid pace" and the unemployment rate has been broadly stable, adding that he views tariffs as a one-time price increase.

Investors, meanwhile, remained to the sidelines as US Treasury Secretary Scott Bessent said that Washington will not seek a trade deal until the South Korean parliament ratifies it.

Large cap shares were trading mixed.

Chip giant Samsung Electronics advanced 1.29 percent, while its rival SK hynix jumped 4.04 percent.

Industry leader Hyundai Motor vaulted 6.19 percent, bio firm Celltrion slid 1.83 percent, and major shipbuilder Hanwha Ocean dipped 2.16 percent.

The local currency was trading at 1,426.3 won against the greenback as of 9:15 a.m., down 3.8 won from the previous session's close. (Yonhap)