The central bank seems so confident of the stability that it introduced a $50 note months after this was announced.
A total of 840 bids worth US$42.3 million were approved, bringing the total so far allotted this year to US$961.9 million.
Business and some politicians have argued that the auction rate is being manipulated.
United States economist Steve Hanke says the black market rate is $142 to the greenback. He, however, says using that rate, inflation in Zimbabwe is now at 46.16%.
Officially it is 106.6%. The central bank expects it to drop to 55% this month and to less than 25% by the end of the year.