South Korean shares extended their winning streak to a fourth session on Tuesday to close at a more than two-year high, helped by advances in tech heavyweights and progress in coronavirus vaccine development. The Korean won rose against the US dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) rose 15.67 points, or 0.65 percent, to close at 2,443.58.

Tuesday's closing marks the highest since June 12, 2018, when the index closed at 2,468.83 points.

Trading volume was moderate at about 840 billion shares worth some 11.7 trillion won ($9.9 billion), with losers outnumbering gainers 423 to 411.

Foreigners bought a net 253 billion won, while retail investors sold a net 77 billion won. Institutions offloaded a net 199 billion won.

Major tech shares led the KOSPI's gain, after a 1.3 percent jump in the previous session, although increased valuation concerns pegged a further hike, analysts said.

"The local stock market showed limited gains today, as some investors apparently turned to profit-taking after yesterday's rally," said Kiwoom Securities analyst Seo Sang-young.

"Still, chipmakers' advances and foreign buying kept the markets bullish," he added.

Growing optimism for COVID-19 vaccines also added vigor to the local stock market.

The chief executive of pharmaceutical giant Pfizer predicted that the United States would be able to deploy a COVID-19 vaccine before the end of the year.

In Seoul, most large caps closed higher.

Market bellwether Samsung Electronics gained 0.99 percent to 61,000 won, with No. 2 chipmaker SK hynix jumping 2.38 percent to 81,900 won.

Top pharmaceutical firm Samsung Biologics rose 1.31 percent to 773,000 won, while Celltrion closed flat at 296,000 won.

Leading chemical maker LG Chem climbed 1.97 percent to 726,000 won, and rechargeable battery maker Samsung SDI surged 3.78 percent to 452,500 won.

Internet portal giant Naver advanced 2.97 percent to 312,000 won, with its rival Kakao up 2.01 percent to 381,000 won.

Hyundai Motor, the country's largest automaker, lost 0.56 percent to 179,000 won, and top steelmaker Posco retreated 0.26 percent to 189,500 won.

The local currency closed at 1,179 won against the US dollar, up 4.5 won from the previous session's close.

Bond prices, which move inversely to yields, closed higher. The yield on three-year Treasurys lost 1.2 basis points to 0.907 percent, and the return on the benchmark five-year government bond fell 1.9 basis points to 1.198 percent. (Yonhap)