South Korean stocks finished lower Thursday after two straight days of robust gains, as investors cashed in part of recent gains. The Korean won lost ground against the US dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) shed 18.52 points, or 1.09 percent, to close at 1,686.24, ending its two-day winning streak.

The index spiked nearly 14.5 percent over the last two days on stimulus hopes. 

Trading volume was high at 982 million shares worth 12.2 trillion won ($9.9 billion), with gainers far outpacing losers 698 to 183.

The index had a choppy session despite stimulus measures announced by major economies. It reached as high as 1,735.75 points following the news that the US Senate has passed a $2 trillion coronavirus relief package.

In Seoul, South Korea's central bank announced that it will supply an "unlimited" amount of liquidity to financial institutions over the next three months to help minimize the economic impact of the COVID-19 crisis.

But it went south as investors attempted to go profit-taking.

"The index see-sawed as stimulus measures were already reflected in the market," said Seo Sang-young, an analyst at Kiwoom Securities. "With no additional factors to lead the upward momentum, the index went down."

Foreigners extended their selling streak to a 16th consecutive session, offloading a net 531 billion won worth of stocks on the main bourse. Institutions dumped a net 214 billion won, while retail investors scooped up a net 716 billion won.

Large caps were mixed, although tech shares closed in negative terrain.

Top market cap Samsung Electronics moved down 1.75 percent to 47,800 won, and No. 2 chipmaker SK hynix plunged 4.5 percent to 80,700 won.

No. 1 carmaker Hyundai Motor rose 0.47 percent to 84,900 won, but its small affiliate Kia Motors shed 0.4 percent to 25,050 won.

Auto parts maker Hyundai Mobis lost 1.47 percent to hit 167,000 won.

Pharmaceutical giant Samsung BioLogics dropped 3.89 percent to 456,500 won, and top steelmaker POSCO slipped 3.42 percent to 155,500 won.

The local currency closed at 1,232.80 won against the US dollar, down 2.9 won from the previous session's close. (Yonhap)