NEW YORK: The dollar index fell to a seven-week low on Thursday, the Australian dollar hit a three-year high and safe havens weakened as global growth optimism sent government debt yields surging worldwide.

Easy financial conditions, the promise of fiscal stimulus and accelerating COVID-19 vaccine rollouts have boosted expectations that growth and inflation will accelerate.

The dollar dipped 0.26% against a basket of currencies to 89.797, its lowest since Jan. 8.

Data on Thursday showed that fewer Americans filed new claims for unemployment benefits last week amid falling COVID-19 infections.

Federal Reserve Chair Jerome Powell reiterated on Wednesday that the US central bank would not tighten its policy until the economy improves.

The Aussie got as high as $0.80007 against the greenback while the kiwi reached $0.7463.

The Canadian dollar got as far as 1.2468 loonies per US dollar.

The euro also gained to a three-week high, despite its bond yield increases lagging other countries. It was last up 0.44% at $1.2224.

The safe-haven Japanese yen, which tends to underperform when global growth improves, weakened as far as 106.20 yen per dollar.

Bitcoin was last up 2.67% on the day at $51,080, having recovered some of its losses from the start of the week.