South Korean stocks inched up on Monday, as investors took to the sidelines amid increased valuation pressure and uncertainties from the Sino-American political friction. The Korean won fell against the US dollar.

After choppy trading, the benchmark Korea Composite Stock Price Index (KOSPI) rose 3.71 points, or 0.12 percent, to close at 3,135.59.

Trading volume was moderate at about 1 billion shares worth around 13.1 trillion won ($11.6 billion), with gainers outnumbering losers 493 to 350.

Foreigners sold a net 324 billion won, while retail investors purchased 691 billion won. Institutions offloaded a net 390 billion won.

Stocks got off to a muted start after the KOSPI snapped its six-day gaining steak the previous session as valuation pressure increased ahead of the earnings report season.

Lingering US-China political friction also pegged the KOSPI's further gains, analysts said.

"Local stock markets seem to be testing the water, with other Asian markets retreating amid rising concerns over the US-China tensions," Kiwoom Securities analyst Seo Sang-young said.

Late last week, the US government added several Chinese supercomputer makers and research labs to its export blacklist, citing technology and security issues.

In Seoul, market kingpin Samsung Electronics lost 0.48 percent to 83,200 won, and No. 2 chipmaker SK hynix shed 1.79 percent to 137,500 won.

Internet portal giant Naver moved up 0.52 percent to 385,500 won, and leading carmaker Hyundai Motor declined 1.09 percent to 226,000 won. Trading was suspended for mobile messenger operator Kakao over share splitting.

Leading chemical maker LG Chem gained 0.62 percent to 817,000 won, while top pharmaceutical firm Samsung Biologics climbed 1.56 percent to 782,000 won.

EV battery maker SK Innovation soared 11.97 percent to 266,500 won after settling its legal dispute with LG Energy Solution in the United States, clearing uncertainties over its business operation.

The local currency closed at 1,124.9 won to the US dollar, down 3.7 won from the previous session's close.

Meanwhile, the tech-laden KOSDAQ market ended at the highest in nearly 21 years.

The secondary market index rose 11.26 points, or 1.14 percent, to close at 1,000.65, marking the first time that it passed the milestone since Sept. 14, 2000.

Total market cap also closed at a record 411.1 trillion won, steeply up from 385.6 trillion won at the final closing last year.

Bond prices, which move inversely to yields, closed higher. The yield on three-year Treasurys lost 2.8 basis points to 1.14 percent, and the return on the benchmark five-year government bond fell 2.8 basis points to 1.550 percent. (Yonhap)