The dollar was headed for its worst week of the year on Friday, as investors cheered in the Joe Biden administration by buying riskier currencies and refreshed bets that a pandemic recovery could push the greenback lower still. Against the euro, the dollar is down almost 0.8% this week and it touched a week-low of $1.2173 per euro on Friday. The dollar index has fallen by the same weekly margin, and was steady at 90.075 early in the Asia session. The euro had found some support from the European Central Bank keeping policy steady and accommodative. Sterling rose to a 2-1/2 year high of $1.3745 overnight on hopes Britain's vaccine roll-out can usher in a rebound in growth. It held at that level on Friday, up 1% for the week. The sentiment-driven moves have eroded gains made by the U.S dollar since the Democrats won control of the U.S. Congress earlier this month. The dollar had risen along with U.S. Treasury yields on expectations of more fiscal stimulus and government borrowing under a Biden administration. The dollar was steady against the Japanese yen on Friday at 103.58, but has lost 0.3% over the week. A heavy sell-off in Bitcoin saw the cryptocurrency drop 5% in Asia trade on Friday to hit an almost three-week low of $28,800.