On 14 November, it had fallen to historic low of 317.90 per euro.
Bond yields, already at a high of two and a half years more than 8% should also be under pressure.
To justify its decision, Moody's described the growing uncertainties about the ability of Hungary to achieve its budgetary targets, the high debt levels and what the rating agency designated as growth prospects in the medium term more mixed.
The Hungarian Ministry of Economy said in a statement that the lowering of the Hungarian sovereign rating to Ba1 by Moody's was part of "financial attacks directed against Hungary."