Investors are bracing for more massive losses with the Australian share market poised to plunge up to five per cent after panic selling smashed global markets overnight.

The SPI200 futures contract was down 284 points, or 4.97 per cent, to 5432 at 0900 AEDT on Tuesday, suggesting falls of up to five per cent when trading begins.

Overnight, stocks on Wall Street plummeted so fast on what traders are now calling “Black Monday” they triggered the first automatic halt in trading in more than two decades.

The Australian Securities Exchange doesn’t have such an automatic trigger, which can increase rather than decrease volatility.

Instead it has “anomalous order thresholds”, which prevent aggressive orders for a stock outside a range of about 10 per cent of its price at any one moment.

The Australian Securities and Investments Commission introduced short selling bans in 2008 during the global financial crisis to help maintain an orderly market but is not proposing that measure at this point.

Short-selling happens when investors try to make money from falling stock prices by borrowing shares to sell on the open market then trying to buy them back at a cheaper price.

The Dow Jones plunged nearly 8 per cent at one point on Monday and European bourses entered a bear market amid panicked global trading as an oil price war between Saudi Arabia and Russia compounded coronavirus woes.

The Australian stock market suffered its worst single day loss in nearly a dozen years on Monday and looks set for another turbulent day.

The wider market shed about $155 billion in value as the benchmark S&P/ASX200 index plunged 7.33 per cent to a two-year low of 5,760.6.

All eyes will be on Prime Minister Scott Morrison on Tuesday as he addresses business leaders in Sydney on Tuesday about a stimulus package to help the economy as the coronavirus threatens industry.

Mr Morrison is expected to also reassure the public that the $10 billion stimulus to be issued later this week will not be funded by cuts to essential services such as schools, hospitals and the National Disability Insurance Scheme.

The NAB business survey due out on Tuesday is expected to reflect the hit to business confidence and conditions from the virus.

The Aussie dollar was buying 65.91 US cents at 0900 AEDT on Tuesday, up from 65.46 US cents at the market close on Monday.