Vietcombank sold the dollar at VND24,880, up 0.12% from Tuesday.
The dollar is sold at VND25,620 on the black market, down 0.19%.
The State Bank of Vietnam (SBV) also hiked its reference rate by 0.02% to VND24,017.
It has increased against the dong by 1.88% since the beginning of the year.
Globally, the U.S. dollar was largely steady on Wednesday, as traders avoided making big bets ahead of congressional testimony from Federal Reserve Chair Jerome Powell, as well as the European Central Bank rate decision and U.S. jobs data later this week, Reuters reported.
In cryptocurrencies, bitcoin was slightly up but stayed below a record high reached in a volatile overnight session.
The dollar index , which measures the greenback's strength against a basket of six currencies, hovered around 103.84.
The euro edged down 0.1% to $1.0846 as traders braced for the ECB's interest rate decision later on Thursday.