SEOUL, Dec. 29 (Yonhap) — South Korean stocks finished at an all-time high on Tuesday, the annual ex-dividend day that is usually marked by choppy trading. The Korean won rose against the U.S. dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) rose 11.91 points, or 0.42 percent, to close at 2,820.51.

Trading volume was particularly high at about 1 billion shares worth some 19.1 trillion won (US$17.5 billion), with gainers outnumbering losers 537 to 334.

The stock index got a boost from massive 2.2 trillion won net buying by individuals, the largest daily purchase since Nov. 30. Foreigners sold a net 314 billion won, and institutions offloaded a net 2 trillion won.

“High-dividend shares, such as financials and telecommunications, seem to have traded weak in today’s ex-dividend session,” Hana Financial Investment analyst Lee Young-gon said.

In contrast, pharmaceutical shares soared, largely due to growing pandemic concerns.

In ex-dividend sessions, investors become eligible to win year-end dividends even after offloading shares.

  Investors were obliged to hold on to their shares until the previous session for year-end dividends. The final trading session of 2020 is Wednesday.Market bellwether Samsung Electronics lost 0.51 percent to 78,300 won, while No.

2 chipmaker SK hynix gained 0.43 percent to 116,000 won.

Top pharmaceutical firm Samsung Biologics jumped 4.18 percent to 822,000 won. Celltrion spiked 10.08 percent to 360,500 won, after the drug safety agency said it launched a review of the drugmaker’s coronavirus treatment.

Internet portal giant Naver rose 0.71 percent to 283,000 won, with its rival Kakao climbing 3.08 percent to 384,500 won.

Leading chemical maker LG Chem slipped 0.12 percent to 813,000 won, and rechargeable battery maker Samsung SDI surged 7.51 percent to 601,000 won.

Hyundai Motor, the country’s largest automaker, moved up 0.53 percent to 190,500 won.

The local currency closed at 1,092.1 won per dollar, up 4.6 won from the previous session’s close.

Bond prices, which move inversely to yields, closed lower. The yield on three-year Treasurys rose 1.5 basis points to 0.973 percent, and the return on the benchmark five-year government bond added 1.1 basis points to 1.327 percent.