The Korean won strengthened to below the 1,400-won mark against the U.S. dollar for the first time in nearly 11 months, while the KOSPI plunged 5.8 percent on Wednesday. The won-dollar exchange rate closed at 1,397.7 won per dollar, down 14.1 won from the previous session. It was the first time that the rate fell below 1,400 won since Oct. 2 last year, when it stood at 1,399.5 won. Companies, including Samsung Electronics and SK hynix, are believed to have sold large amounts of dollars ahead of this month's interim corporate tax payments. Recent U.S. consumer and producer price data also came in below expectations, strengthening views that the Federal Reserve will refrain from raising rates next month. In contrast, the stock market was hit by a sharp sell-off amid growing concerns over rising global bond yields. The benchmark KOSPI closed at 6,471.17, down 5.8 percent. The index opened 4.96 percent lower and extended its losses, triggering a sell-side sidecar at 9:06 a.m. It was the 48th sidecar activation on KOSPI this year. Foreign and institutional investors sold a net 3.49 trillion wo