The KOSPI surged more than 4% on the 27th, triggering a buy-side sidecar — a five-minute suspension of program trading buy orders — on the main board for the first time in four trading sessions.
At 10:13:53 a.m., KOSPI 200 futures rose 5.05% from the previous session's close, halting the effect of program trading buy orders for five minutes, according to the Korea Exchange. A buy-side sidecar kicks in when KOSPI 200 futures stay up 5% or more from the prior close for one minute, suspending program trading buy orders for five minutes. It was the first buy-side sidecar on the KOSPI since the 21st of this month, four sessions earlier.
As of 10:17 a.m., the KOSPI traded at 5,701.55, up 232.08 points, or 4.24%, from the previous session. Foreign and institutional investors drove the index higher with net purchases of 428 billion won and 271.1 billion won, respectively. Retail investors sold a net 724.3 billion won. Program trading showed net buying of 441.1 billion won.
Large-cap stocks also rallied. Samsung Electronics traded at 224,250 won, up 5.28%, while SK hynix rose 7.37% to 1,369,000 won. SK Square gained 11.05% and Samsung Electro-Mechanics climbed 9.66%.
The rally was attributed to easing concerns over profitability in the artificial intelligence industry after U.S. AI company Anthropic moved toward an initial public offering. Expectations for AI chip demand revived after Anthropic's first-half revenue was reported to have risen about 1,300% from a year earlier. Analysts said bargain hunting flowed into large-cap chip stocks, helped by a 2.82% gain in the Philadelphia Semiconductor Index overnight and the KOSPI's drop of more than 20% this month.