The Australian dollar has surged against its US counterpart which has fallen ahead of key Congressional testimony by Federal Reserve chair Janet Yellen, after a Donald Trump Jnr e-mail came to light.

At 0635 AEST on Wednesday, the Australian dollar was worth 76.34 US cents, up from 76.18 US cents on Tuesday.

BK Asset Management FX managing director Kathy Lien said the US dollar had reversed it gains, and had fallen particularly against the yen and the euro, though not sterling.

The dollar fell to a more than one-week low against a basket of major currencies on Tuesday, after US president Donald Trump’s eldest son released an email chain citing Russian support for his father before last year’s US election.

The greenback’s movements, and therefore its stance against the Aussie dollar, over the next few likely will depend on the tone of Federal Reserve chair Janet Yellen’s congressional testimony.

“The (US) dollar will rise if she emphasises the need for continued gradual removal of policy accommodation and will crash hard if she is noncommittal about additional tightening,” Lien said in a Wednesday morning note.

FX Techs’ Niall O’Connor says it is likely the local currency will reverse its course.

“AUD/USD is impulsively reversing from the important .7725/50 area, as the momentum setup suggests a shift is due,” he said in a morning note.

The Aussie dollar is lower against both the yen and the euro.

AAP

Access exclusive analysis, locked news and reports with Inside Retail Weekly. Subscribe today and get our premium print publication delivered to your door every week.