SEOUL, July 16 (Xinhua) -- South Korean stocks dropped over 6 percent on Thursday, triggering temporary trading halts amid big tech sell-offs, driven by reignited concerns over domestic semiconductor manufacturers.
The benchmark KOSPI dived 463.81 points, or 6.37 percent, to close at 6,820.60, while the smaller KOSDAQ tumbled 37.59 points, or 4.53 percent, to finish at 791.84.
In the morning session, sell-side sidecars were issued in both the KOSPI and KOSDAQ markets due to sharp stock price falls in Samsung Electronics and SK hynix.
The sidecar is activated when the benchmark futures index fluctuates for at least one minute by 5 percent for KOSPI and 6 percent for KOSDAQ, which also requires a 3 percent spot index move, leading to a temporary halt of program trading for five minutes.
The local stock market continued an extreme, rollercoaster volatility after buy sidecars were triggered on Monday.
The Bank of Korea (BOK)'s policy rate hike in three and a half years also added downward pressure on the domestic stock market.
Foreign and institutional investors were net sellers, dumping major semiconductor stocks, while retail investors went on buying the dip.
The South Korean won versus U.S. dollar exchange rate finished its daytime session at 1,480.4 won per dollar as of 3:30 p.m. local time (0630 GMT), down 4.3 won from the previous session's daytime close.
Market bellwether Samsung Electronics and memory chip giant SK hynix plunged 8.77 percent and 11.53 percent.
The country's top automaker Hyundai Motor slipped 2.07 percent, and the largest battery maker LG Energy Solution lost 0.30 percent.
The No. 1 biopharmaceutical contract manufacturer Samsung Biologics rose 0.94 percent, and the leading aerospace and defense company Hanwha Aerospace gained 1.51 percent.
The biggest shipbuilder HD Hyundai Heavy Industries increased 2.76 percent, but the energy infrastructure leader Doosan Enerbility was down 4.52 percent. ■