Vietcombank sold the dollar at VND24,740, down 0.04% from Wednesday.
The State Bank of Vietnam raised its reference rate by 0.04% to VND24,099.
The dollar was stable at VND24,600 on the black market.
It has increased against the dong by 4.26% since the beginning of the year.
Globally, the dollar fell broadly on Thursday, with risk-sensitive Asian currencies leading gains, as investors cheered a likely peak in U.S. interest rates after the Federal Reserve left them on hold, Reuters reported.
The Australian dollar jumped 0.9% on Wednesday and another 0.7% on Thursday to touch a three-week high of $0.6439. The New Zealand dollar hit a two-week peak of $0.5896.
Bitcoin, sometimes traded as a proxy for risk-taking, broke above $35,000 for the first time since May 2022.
The euro rose 0.2% to $1.0597, the Swiss franc rose for a second day in a row and the yen was helped off a one-year low to 150.45.