South Korea's KOSPI falls more than 2 percent in early trading on Sept. 11, slipping to the 6,800 level. Caution grows ahead of the release of U.S. August consumer price index (CPI) data. Profit-taking emerges, led by semiconductor stocks that have driven recent gains.

As of 9:10 a.m., the KOSPI is down 181.81 points, or 2.58 percent, from the previous session at 6,852.11. The index opens down 231.42 points, or 3.29 percent, at 6,802.50.

In the main board market, retail investors are net buyers of 452.1 billion won. Foreigners and institutions are net sellers of 223.7 billion won and 287.5 billion won, respectively.

Semiconductor stocks that have led the recent rise in the index are weaker. Samsung Electronics is trading at 259,500 won, down 3.53 percent from the previous session, and SK Hynix is down 4.10 percent at 1,777,000 won.

SK Square is down 4.76 percent, LG Energy Solution falls 1.92 percent, Hyundai Motor declines 2.25 percent, Samsung Biologics slips 0.84 percent and Samsung Life falls 1.94 percent. KB Financial Group is up 0.69 percent.

The Kosdaq is also lower. At the same time, the Kosdaq is down 13.12 points, or 1.57 percent, from the previous session at 823.80.

In the Seoul foreign exchange market, the won is at 1,347.40 per dollar, down 3.60 won, or 0.27 percent, from the previous session.

Han Ji-young (한지영), an analyst at Kiwoom Securities, said it was worth noting that although the KOSPI at one point fell below 7,000 in intraday trading a day earlier, it later recovered losses and closed above 7,000 for a second straight session. She said short-term volatility could increase depending on the U.S. CPI result, but it is important whether rotation continues into power equipment, nuclear power and small- and mid-cap stocks.