VN-Index drops most in six weeks amid global sell-off. Vietnamese stocks suffered their biggest pullback Monday since early August as growing investor concern that the US Fed will raise interest rates later this month sparked a global risk-off, flight to safety trade. The market opened lower and bottomed at 655 in the afternoon before closing down 7.12 points, or 1.1%, to 659.76, which reduced the short-term technical bias to bearish from neutral.