Australian shares are poised to plunge after another rout on US equity markets overnight as investors wait for the promised major US government stimulus response.

The SPI200 futures contract was down 200 points, or 3.49 per cent, at 5528 at 0700 AEDT on Thursday.

US equity markets plunged into fear mode on Wednesday leaving the S&P500 down 4.79 per cent, and the Dow Jones losing 5.54 per cent.

“Markets appeared concerned at the lack of US government response to date, the WHO officially declaring COVID-19 a pandemic, and the number of new cases ex-China rose sharply, Westpac finance’s morning note says.

The Australian dollar was buying 64.87 US cents at 0700 AEDT on Thursday, down from 65.05 US cents from at the market close on Wednesday.