Stock markets are on course for a fresh sell-off, unwinding two days of recovery, despite the $2trn (£1.7trn) US coronavirus relief scheme clearing its first hurdle.
The package of federal government help for the world's largest economy to battle disruption caused by COVID-19 overcame last minute Democrat opposition to secure passage in a Senate vote overnight.
The House of Representatives will get its say on Friday. Donald Trump is then expected to sign the Bill into law.
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Stock markets had rallied on Tuesday and Wednesday on hopes the measures - the largest programme of support ever initiated - would have a smooth passage as investors eye the prospect of a recession deeper than that caused by the financial crisis in 2008.
The package includes $58bn for the mostly-grounded airline industry - split between grants and loans to cover pay cheques - with companies drawing support unable to cut staff until the end of September or change their labour agreements.
Advertisement Crisis-hit Boeing, already reeling from the grounding of the 737 MAX, gets $17bn.
Image: Boeing 737 MAX planes were grounded a year ago after a second fatal crash It is understood most Americans would qualify for cheques of up to $1,200 each.
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Stimulus by governments and central banks globally has had a limited effect on supporting investor confidence - with stock market values more than 20% down, on average, ahead of Thursday's open.
After a jittery finish to trading in the US, the Nikkei in Tokyo was 4.5% down amid falls across Asia.
In London, the FTSE 100 Index was forecast to open almost 2% lower.