The dollar index hit its lowest in over two years on Thursday, while the euro rises above $1.21 as indications of progress towards the US fiscal stimulus and encouragement over vaccines made investors more ready to move funds to volatile assets.Lawmakers in Washington have failed to reach an agreement on economic stimulus to help relieve the impact of coronavirus in the US, but there were early indications that a $908 billion bipartisan proposal could be gaining attraction.Risk appetite was also fueled by optimism over recent developments towards the roll-out of coronavirus vaccines. The UK approved Pfizer Inc’s vaccine on Wednesday.The dollar dropped, going as low as 90.834 in opposition to a bunch of currencies- its lowest since April 2018. At 0820 GMT it was at 90.890, down 0.1% on the day.