South Korean stocks extended their gaining streak to an eighth session on Wednesday on hopes for COVID-19 vaccines and optimism for a quick economic rebound from the impacts of the new coronavirus pandemic. The Korean won rose against the US dollar.

After choppy trading, the benchmark Korea Composite Stock Price Index (KOSPI) rose 13.68 points, or 0.57 percent, to close at 2,432.35.

Trading volume was high at about 753 million shares worth some 16.4 trillion won ($13.8 billion), with losers outnumbering gainers 446 to 415.

Foreigners sold a net 176 billion won, while retail investors purchased a net 356 billion won. Institutions offloaded a net 203 billion won.

The local stock market was bearish in the morning, as investors weighed profit-taking in the week-long rally. But it turned upward in the last 30 minutes before the session's close, with investors betting that the index has room for further growth. 

"The continued rally is backed by ample liquidity, better-than-expected corporate earnings in the first half and expectations for a rebound next year," Kang Bong-joo, a researcher at Meritz Securities, said.

Investor sentiment was also boosted by rosy expectations for brisk global demand for chips and pharmaceutical products.

Large caps closed mixed with Samsung affiliates logging decent gains.

Market bellwether Samsung Electronics advanced 1.37 percent to 59,000 won, while No. 2 chipmaker SK hynix slid 0.37 percent to 81,000 won.

Top pharmaceutical company Samsung Biologics spiked 4.85 percent to 843,000 won on expectations of expanded capacity. Samsung C&T, a large shareholder of Samsung Biologics, shot up 8.14 percent to 119,500 won.

In contrast, automakers finished lower as investors cashed in part of recent gains. Hyundai Motor, the country's largest automaker, dipped 3.91 percent to 172,000 won, with its smaller affiliate Kia Motors down 4.13 percent to 45,250 won.

Internet giant Naver lost 2.09 percent to 305,000 won, while its rival Kakao added 0.43 percent to 354,000 won.

Leading steelmaker POSCO climbed 0.72 percent to 208,500 won.

The local currency was trading at 1185.30 won against the US dollar, up 0.30 won from the previous session's close.

Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys rose 0.9 basis point to 0.827 percent, and the return on the benchmark five-year government bond added 1.0 basis point to 1.087 percent. (Yonhap)