VN-Index falls for first day in five, still has best week in 10 months. Vietnamese stocks opened higher and jumped to above 668 in the first 30 minutes of trading, suggesting the market would close out the week with a fifth straight day of gains. However, the index quickly reversed, still staying in positive territory until the afternoon session, when investors couldn't resist some profit taking ahead of the weekend. The index closed down 4.53 points, or 0.7%, to 655.71.