Seoul shares ended slightly lower Thursday on renewed concerns about artificial intelligence(AI) valuations.

The benchmark Korea Composite Stock Price Index dipped seven‑point‑79 points, or zero‑point‑19 percent, to close at four‑thousand‑28‑point‑51.

Turnover was moderate at 348‑point‑16 million shares worth 13‑point‑57 trillion won, or nine‑point‑two billion U.S. dollars, with decliners outnumbering advancers 592 to 283.

Fragile sentiment in chip stocks deepened after Microsoft slid as much as three percent on reports of reduced AI sales quotas, weighing on Nvidia and Micron Technology and reviving worries across the sector.

Samsung Electronics rose zero‑point‑57 percent to 105‑thousand‑100 won, while SK hynix dropped one‑point‑81 percent to 542‑thousand won.

Battery maker LG Energy Solution slipped one‑point‑91 percent to 410‑thousand won.

Automakers advanced, with Hyundai Motor surging six‑point‑38 percent to 283‑thousand‑500 won and Kia rising one‑point‑43 percent to 120‑thousand‑300 won on easing tariff concerns.

Earlier in the day, the United States posted a Federal Register notice implementing elements of the South Korea‑U.S. trade deal, including a retroactive cut in import tariffs on South Korean automobiles to 15 percent, effective Nov. 1.

The tech‑heavy KOSDAQ edged down two‑point‑18 points, or zero‑point‑23 percent, to close at 929‑point‑83.

The South Korean won weakened against the U.S. dollar by five‑point‑five won, trading at one‑thousand‑473‑point‑five won as of 3:30 p.m.