Seoul shares closed lower on Friday, ending a six-session winning streak as investors locked in profits from technology and other large-cap stocks. The Korean won sharply depreciated against the U.S. dollar.
South Korea's benchmark Korea Composite Stock Price Index (KOSPI) fell 63.14 points, or 1 percent, to close at 6,244.13 on Friday. The index still posted a weekly gain of 7.5 percent.
Trading volume was heavy at 1.14 billion shares valued at 52.94 trillion won (US$36.8 billion), with decliners outnumbering gainers 625 to 264.
The KOSPI has been in a bullish phase since the start of the year, surpassing 4,500 points for the first time on Jan. 6 and crossing 5,000 on Jan. 27. It broke through 6,000 points on Wednesday, less than a month later.
On Thursday, the index surged 3.67 percent to a record high of 6,307.27.
Institutional investors net bought 491.99 billion won worth of shares, and retail investors net purchased 6.08 trillion won, while foreign investors net sold 6.83 trillion won.
Analysts attributed the decline to overnight losses in U.S. technology stocks, where profit-taking occurred despite strong earnings from Nvidia Corp.
The tech-heavy Nasdaq Composite dropped 1.18 percent, while the Dow Jones Industrial Average edged up 0.03 percent.
"Some investors sold shares to lock in profits after the market had rallied sharply over the past six sessions," said Lee Seong-hoon, an analyst at Kiwoom Securities Co.
Technology stocks led the declines. Market bellwether Samsung Electronics fell 0.69 percent to 216,500 won, and SK hynix declined 3.46 percent to 1,061,000 won.
Leading shipbuilder HD Hyundai dropped 1.02 percent to 292,500 won, and shipping firm HMM shed 4.26 percent to 21,350 won.
Among gainers, top carmaker Hyundai Motor jumped 10.67 percent to an all-time high of 674,000 won, and defense firm Hanwha Aerospace climbed 0.08 percent to 1,195,000 won.
Leading steelmaker POSCO Holdings rose 1.35 percent to 413,000 won, and No. 2 steelmaker Hyundai Steel surged 19.85 percent to 46,500 won.
The Korean won traded at 1,439.70 per U.S. dollar at 3:30 p.m., down 13.9 won from the previous session.
Bond yields fell, with the three-year Treasury yield down 2.1 basis points to 3.041 percent and the five-year government bond yield declining 3.6 basis points to 3.278 percent.