South Korean stocks snapped a five-day winning streak Friday, as investors took to the sidelines to lock in gains amid increased valuation pressure. The Korean won fell against the US dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) retreated 7.35 points, or 0.23 percent, to close at 3,240.08 points.

Trading volume was moderate at about 1.4 billion shares worth some 15.8 trillion won ($14.2 billion), with losers outnumbering gainers 483 to 371.

Foreigners bought a net 162 billion won, while institutions sold 658 billion won. Retail investors bought a net 471 billion won.

The KOSPI got off to a weak start after finishing only an inch away from its all-time high the previous session.

Investor sentiment remained weak ahead of the reveal of US' monthly jobs data on Friday (US time), with lingering concerns of volatility over US tapering jitters.

The KOSPI trimmed part of its losses in the afternoon, as investors were optimistic the rising COVID-19 vaccination rate would hasten the economic rebound at home and overseas.

"Investors' eyes are on the vaccination rate and the bond yields, hoping the social distancing measures in the United States, Europe and the emerging economies will be eased," Eugene Investment & Securities analyst Huh Jae-hwan said.

"There are uncertainties about the US (monthly) jobs data and the next FOMC meeting, but the inflation concerns seem to be well-contained for now," he said.

In Seoul, market bellwether Samsung Electronics declined 0.72 percent to 82,200 won, and No. 2 chipmaker SK hynix shed 0.39 percent to 128,500 won.

Internet portal operator Naver moved down 1.38 percent to 357,000 won, while giant pharmaceutical firm Samsung Biologics advanced 1.94 percent to 840,000 won.

Top automaker Hyundai Motor climbed 1.26 percent to 241,500 won, but leading chemical firm LG Chem decreased 0.37 percent to 809,000 won.

The local currency closed at 1,116.5 won against the US dollar, down 2.9 won from the previous session's close. (Yonhap)