Seoul shares extended their winning streak for a fourth straight session on Wednesday, setting a new record on strong gains in tech and auto stocks.

The benchmark Korea Composite Stock Price Index rose 25‑point‑58 points, or zero‑point‑57 percent, to close at four‑thousand‑551‑point‑06. The main bourse briefly surpassed the four‑thousand‑600 mark, hitting an intraday high of four‑thousand‑611‑point‑72.

Trading volume was heavy at 548‑point‑38 million shares worth 28‑point‑83 trillion won, about 19‑point‑nine billion U.S. dollars, with losers outnumbering gainers 683 to 199.

Samsung Electronics gained one‑point‑51 percent to 141‑thousand won, while SK hynix climbed two‑point‑two percent to 742‑thousand won.

Hyundai Motor skyrocketed 13‑point‑eight percent to 350‑thousand‑500 won after Hyundai‑owned Boston Dynamics showcased its humanoid robot Atlas for the first time at this year’s Consumer Electronics Show(CES) Monday in Las Vegas. Kia jumped five‑point‑55 percent to 129‑thousand‑300 won.

HD Hyundai Heavy Industries added one‑point‑27 percent on the back of a series of high‑end ship orders.

Among decliners, Korean Air and Korea Electric Power Corp. both slipped one‑point‑78 percent.

Refiner SK Innovation plunged three‑point‑77 percent, while LG Energy Solution dropped one‑point‑98 percent.
 
The tech-heavy KOSDAQ lost eight-point-58 points, or zero-point-nine percent, to close at 947-point-39.
 
The South Korean won weakened against the U.S. dollar by zero-point-three won, trading at one-thousand-445-point-eight won as of 3:30 p.m.