The interbank dollar exchange rate rose the eighth time, gaining VND15 per dollar to VND20,723 per dollar on October 18.
The rate has surged VND95 per dollar, or 0.46 percent, this month.
Commercial banks immediately adjusted their exchange rates after the central bank lifted up the price. Vietcombank bought dollars at VND20,925 per dollar, and sold at VND20,930 per dollar. Eximbank sold dollars at the same price, but bought at VND20,910, VND15 per dollar lower than Vietcombank.
Meanwhile, despite the heat of bank dollars, the rate hovered around VND21,370-21,470 on free market recently.
As the capital mobilized from residents strongly declined, some banks had to rely on the interbank lending market, causing the rate to jump to 30 percent per annum for one-month terms.
Overnight rate climbed to 16 percent per annum; rates for one-week terms were around 18 percent per annum.