Vietnam's benchmark VN Index inched up 0.25 percent on Friday, buoyed by banking stocks, but most investors preferred to stay on the sidelines due to a lack of supportive news. The country's four out of six listed lenders rallied, including Vietcombank, the country's second-biggest bank by market value, and BIDV. Vietcombank rose 1.66 percent, while BIDV advanced 0.58 percent. The index, Southeast Asia's best performer last year, has lost 0.65 percent this week, after falling 0.25 percent last week, Thomson Reuters data showed.