The KOSPI hit another record high and passed the 4,800 mark. In just this week, it set a big milestone by crossing 4,600, 4,700 and 4,800 points in succession. Since the New Year, the KOSPI index has risen for 11 straight trading days, nearing the all-time longest streak of "13 trading days." Semiconductors and nuclear power led the market's gains on the day.
The KOSDAQ also finished higher. It opened lower early in the session, but buying picked up around biotech stocks after Alteogen hinted at an additional technology transfer at the JP Morgan Healthcare Conference (JPMHC 2026).
On the 16th, the KOSPI index closed at 4,840.74, up 43.19 points (0.9%) from the prior trading day. Starting at 4,820.66, the KOSPI index topped the 4,850 level intraday on institutional buying, but it gave back part of its gains late in the session as individual selling intensified.
In the main board, foreigners and institutions were net buyers of 405.0 billion won and 338.5 billion won, respectively. However, institutional buying was driven largely by exchange-traded funds (ETFs) with strong retail characteristics, which were net buyers of 541.5 billion won, while the National Pension Service and other long-term investors were net sellers of 90.1 billion won. Individuals were net sellers of 938.1 billion won.
With TSMC's record results and growing expectations for a policy environment favorable to semiconductors, buying flowed into chip stocks. On the 15th (local time), the United States lowered the semiconductor tariff on Taiwan from 25% to 15% through trade talks, and expectations spread that Korea could receive the same tariff benefit under most-favored-nation provisions. On the day, Samsung Electronics and Samsung Electronics preferred (4.12%), SK hynix (0.93%), and SK Square (3.96%) all finished higher.
On expectations for rising power demand from semiconductors, nuclear-related stocks were also strong, with Doosan Enerbility (6.48%), Korea Electric Power Corporation (1.67%), KEPCO E&C (11.73%), and KEPCO KPS (4.72%) advancing.
While some worry about elevated levels as the KOSPI rally continues, brokerages say valuation pressure is not severe. Lim Jeong-eun, a KB Securities analyst, said, "As of the 15th, the KOSPI 12-month forward price-earnings ratio (PER) is 10.3 times, which is not burdensome," adding, "It is likely to maintain a positive trend for the time being."
The KOSDAQ index also closed at 954.59 points, up 3.43 points (0.36%) from the prior trading day. The index opened at 950.83 and widened losses on foreign selling during the session, then rebounded as market-friendly news emerged at JPMHC 2026 and individual buying came in.
In the KOSDAQ market, individuals and institutions led the index higher with net purchases of 57.1 billion won and 37.9 billion won, respectively, while foreigners were net sellers of 83.3 billion won.
Alteogen, which hinted at a large-scale technology transfer at JPMHC 2026, jumped 10%. Alteogen President Jeon Tae-yeon said, "We plan to announce a technology transfer for ALT-B4 as early as next week," adding, "It will be similar in scale to prior transfers." The market expects, based on past cases, that the deal size could range from several hundred billion won to the trillion-won level.
As buying sentiment spread across biotech, biotech stocks finished higher. ABL Bio (2.54%), Sam Chun Dang Pharm (10.06%), Kolon TissueGene (3.46%), LigaChem Biosciences (2.33%), and Peptron (0.65%) all rose.