European session review: USD weakens amid renewed optimism on U.S. stimulus talks and COVID-19 vaccine progress

USD fell against its major rivals in the European session on Wednesday as anticipations of a rollout of effective COVID-19 vaccines and progress in fiscal stimulus talks between Democrats and Republicans boosted investors' risk appetite. 

The U.S. Dollar Index (DXY), measuring the U.S. currency's value relative to a basket of foreign currencies, edged down 0.1% to 90.89.

The U.S. Food and Drug Administration is to meet on Thursday to discuss an emergency use authorization of the Pfizer/BioNTech's coronavirus vaccine. On 17 December, the FDA will also consider the emergency use approval of the vaccine, designed by Moderna. The vaccine rollout is expected in the days that follow the approvals.

Late Tuesday, U.S. Treasury Secretary Steven Mnuchin offered a new $916 bln stimulus bill to Democrats, which, however, doesn't include supplementary jobless benefits. The House Speaker Nancy Pelosi said any bill must include unemployment benefit payments to get Democratic support. Anyway, a surprise coronavirus relief proposal marked progress in stimulus talks between the Republican and Democratic leaders, rising hopes that the agreement could be reached before the end of the week.