A financial data screen at Hana Bank's dealing room in central Seoul shows the benchmark Kospi standing at 7,612.86, and Samsung Electronics trading at 293,250 won per share, Thursday. (Yonhap) The South Korean benchmark Kospi surged on Thursday, led by a sharp rally in Samsung Electronics after the memory chip giant averted a strike through a last-minute labor agreement.The Kospi opened 3.85 percent higher at 7,486.37, and extended gains to briefly surpass the 7,700 level during trading, according to the Korea Exchange. As of 2 p.m., the index stood at 7,788 points, advancing 8.04 percent on-session.The index regained momentum after Samsung Electronics, the market’s biggest heavyweight, avoided a full-scale strike, boosting investor sentiment, while an overnight rebound in US semiconductor stocks following stronger-than-expected earnings from Nvidia added further support.Amid the rally, a buy-side sidecar was triggered on the Kospi at 9:24 a.m. after Kospi 200 futures surged 5.04 percent from the previous session. The buying curb was also activated on the Kosdaq at 9:27 a.m., marking the first time since April 1 that sidecars had been triggered on both markets.As of 2 p.m., foreign investors were net sellers of 437.4 billion won ($291.6 million) on the Kospi, extending their selling streak to an 11th consecutive session. Retail investors also offloaded a net 1.81 billion won, while institutional investors alone purchased a net 2.29 trillion won, lifting the benchmark index.Semiconductor heavyweights led the rebound. Samsung Electronics shares climbed 7.61 percent to 297,000 won, while Shares of SK hynix also rose 11.12 percent to 1.94 million won.A surge in Samsung Electronics shares pushed the combined market capitalization of listed Samsung Group affiliates to 2,151.56 trillion won, well above the 2,000 trillion won mark during trading.Chip-led buying momentum spread across large-cap shares throughout the market. SK Square gained 13.02 percent to 1.16 million won. Hyundai Motor rose 11.66 percent to 661,000 won.The Kosdaq also posted sharp gains. The junior bourse opened 2.77 percent higher at 1,085.3 from the previous session and climbed 4.82 percent to 1,106.97 as of 2 p.m.